2016
Pinto, Camila Bonin; Velez, Faddi Ghassan Saleh; Bolognini, Nadia; Crandell, David; Merabet, Lotfi B; Fregni, Felipe
In: JMIR Res Protoc, vol. 5, no. 3, 2016, ISSN: 1929-0748.
@article{Pinto2016,
title = {Optimizing Rehabilitation for Phantom Limb Pain Using Mirror Therapy and Transcranial Direct Current Stimulation: A Randomized, Double–Blind Clinical Trial Study Protocol},
author = {Camila Bonin Pinto and Faddi Ghassan Saleh Velez and Nadia Bolognini and David Crandell and Lotfi B Merabet and Felipe Fregni},
doi = {10.2196/resprot.5645},
issn = {1929-0748},
year = {2016},
date = {2016-00-00},
journal = {JMIR Res Protoc},
volume = {5},
number = {3},
publisher = {JMIR Publications Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2015
Rinaldi, Luca; Vecchi, Tomaso; Fantino, Micaela; Merabet, Lotfi B; Cattaneo, Zaira
The effect of hand movements on numerical bisection judgments in early blind and sighted individuals Journal Article
In: Cortex, vol. 71, pp. 76–84, 2015, ISSN: 1973-8102.
@article{pmid26184675,
title = {The effect of hand movements on numerical bisection judgments in early blind and sighted individuals},
author = {Luca Rinaldi and Tomaso Vecchi and Micaela Fantino and Lotfi B Merabet and Zaira Cattaneo},
doi = {10.1016/j.cortex.2015.06.005},
issn = {1973-8102},
year = {2015},
date = {2015-10-01},
journal = {Cortex},
volume = {71},
pages = {76--84},
abstract = {Recent evidence suggests that in representing numbers blind individuals might be affected differently by proprioceptive cues (e.g., hand positions, head turns) than are sighted individuals. In this study, we asked a group of early blind and sighted individuals to perform a numerical bisection task while executing hand movements in left or right peripersonal space and with either hand. We found that in bisecting ascending numerical intervals, the hemi-space in which the hand was moved (but not the moved hand itself) influenced the bisection bias similarly in both early blind and sighted participants. However, when numerical intervals were presented in descending order, the moved hand (and not the hemi-space in which it was moved) affected the bisection bias in all participants. Overall, our data show that the operation to be performed on the mental number line affects the activated spatial reference frame, regardless of participants' previous visual experience. In particular, both sighted and early blind individuals' representation of numerical magnitude is mainly rooted in world-centered coordinates when numerical information is given in canonical orientation (i.e., from small to large), whereas hand-centered coordinates become more relevant when the scanning of the mental number line proceeds in non-canonical direction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recent evidence suggests that in representing numbers blind individuals might be affected differently by proprioceptive cues (e.g., hand positions, head turns) than are sighted individuals. In this study, we asked a group of early blind and sighted individuals to perform a numerical bisection task while executing hand movements in left or right peripersonal space and with either hand. We found that in bisecting ascending numerical intervals, the hemi-space in which the hand was moved (but not the moved hand itself) influenced the bisection bias similarly in both early blind and sighted participants. However, when numerical intervals were presented in descending order, the moved hand (and not the hemi-space in which it was moved) affected the bisection bias in all participants. Overall, our data show that the operation to be performed on the mental number line affects the activated spatial reference frame, regardless of participants' previous visual experience. In particular, both sighted and early blind individuals' representation of numerical magnitude is mainly rooted in world-centered coordinates when numerical information is given in canonical orientation (i.e., from small to large), whereas hand-centered coordinates become more relevant when the scanning of the mental number line proceeds in non-canonical direction.
Bauer, Corinna; Yazzolino, Lindsay; Hirsch, Gabriella; Cattaneo, Zaira; Vecchi, Tomaso; Merabet, Lotfi B
Neural correlates associated with superior tactile symmetry perception in the early blind Journal Article
In: Cortex, vol. 63, pp. 104–117, 2015, ISSN: 1973-8102.
@article{pmid25243993,
title = {Neural correlates associated with superior tactile symmetry perception in the early blind},
author = {Corinna Bauer and Lindsay Yazzolino and Gabriella Hirsch and Zaira Cattaneo and Tomaso Vecchi and Lotfi B Merabet},
doi = {10.1016/j.cortex.2014.08.003},
issn = {1973-8102},
year = {2015},
date = {2015-02-01},
journal = {Cortex},
volume = {63},
pages = {104--117},
abstract = {Symmetry is an organizational principle that is ubiquitous throughout the visual world. However, this property can also be detected through non-visual modalities such as touch. The role of prior visual experience on detecting tactile patterns containing symmetry remains unclear. We compared the behavioral performance of early blind and sighted (blindfolded) controls on a tactile symmetry detection task. The tactile patterns used were similar in design and complexity as in previous visual perceptual studies. The neural correlates associated with this behavioral task were identified with functional magnetic resonance imaging (fMRI). In line with growing evidence demonstrating enhanced tactile processing abilities in the blind, we found that early blind individuals showed significantly superior performance in detecting tactile symmetric patterns compared to sighted controls. Furthermore, comparing patterns of activation between these two groups identified common areas of activation (e.g. superior parietal cortex) but key differences also emerged. In particular, tactile symmetry detection in the early blind was also associated with activation that included peri-calcarine cortex, lateral occipital (LO), and middle temporal (MT) cortex, as well as inferior temporal and fusiform cortex. These results contribute to the growing evidence supporting superior behavioral abilities in the blind, and the neural correlates associated with crossmodal neuroplasticity following visual deprivation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Symmetry is an organizational principle that is ubiquitous throughout the visual world. However, this property can also be detected through non-visual modalities such as touch. The role of prior visual experience on detecting tactile patterns containing symmetry remains unclear. We compared the behavioral performance of early blind and sighted (blindfolded) controls on a tactile symmetry detection task. The tactile patterns used were similar in design and complexity as in previous visual perceptual studies. The neural correlates associated with this behavioral task were identified with functional magnetic resonance imaging (fMRI). In line with growing evidence demonstrating enhanced tactile processing abilities in the blind, we found that early blind individuals showed significantly superior performance in detecting tactile symmetric patterns compared to sighted controls. Furthermore, comparing patterns of activation between these two groups identified common areas of activation (e.g. superior parietal cortex) but key differences also emerged. In particular, tactile symmetry detection in the early blind was also associated with activation that included peri-calcarine cortex, lateral occipital (LO), and middle temporal (MT) cortex, as well as inferior temporal and fusiform cortex. These results contribute to the growing evidence supporting superior behavioral abilities in the blind, and the neural correlates associated with crossmodal neuroplasticity following visual deprivation.
Bauer, Corinna; Yazzolino, Lindsay; Hirsch, Gabriella; Cattaneo, Zaira; Vecchi, Tomaso; Merabet, Lotfi B.
Neural correlates associated with superior tactile symmetry perception in the early blind Journal Article
In: Cortex, vol. 63, pp. 104–117, 2015, ISSN: 0010-9452.
@article{Bauer2015,
title = {Neural correlates associated with superior tactile symmetry perception in the early blind},
author = {Corinna Bauer and Lindsay Yazzolino and Gabriella Hirsch and Zaira Cattaneo and Tomaso Vecchi and Lotfi B. Merabet},
doi = {10.1016/j.cortex.2014.08.003},
issn = {0010-9452},
year = {2015},
date = {2015-02-00},
journal = {Cortex},
volume = {63},
pages = {104--117},
publisher = {Elsevier BV},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hirsch, Gabriella V; Bauer, Corinna M; Merabet, Lotfi B.
Using structural and functional brain imaging to uncover how the brain adapts to blindness Journal Article
In: Annals of Neuroscience and Psychology, vol. 2, no. 5, 2015.
@article{hirsch2015using,
title = {Using structural and functional brain imaging to uncover how the brain adapts to blindness},
author = {Gabriella V Hirsch and Corinna M Bauer and Lotfi B. Merabet},
url = {http://www.vipoa.org/journals/pdf/5856124233.pdf},
year = {2015},
date = {2015-01-01},
journal = {Annals of Neuroscience and Psychology},
volume = {2},
number = {5},
abstract = {Advances in neuroimaging technology have been instrumental in uncovering the dramatic neurological changes that result from blindness, as well as revealing the inner workings of the human brain. Specifically, modern imaging techniques enable us to examine how the brain adapts and “re-wires” itself as a result of changes in behavior, the environment, injury, or disease; a process referred to as neuroplasticity. Following an overview of commonly employed neuroimaging techniques, we discuss structural and functional neuroplastic brain changes associated with profound visual deprivation. In particular, we highlight how associated structural changes often occur within areas that process intact senses (such as hearing, touch, and smell) while functional changes tend to implicate areas of the brain normally ascribed to the processing of visual information. Evidence will primarily focus on profound blindness due to ocular cause, but related work in cerebral/cortical visual impairment (CVI) will also be discussed. The potential importance of these findings within the context of education and rehabilitation is proposed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Advances in neuroimaging technology have been instrumental in uncovering the dramatic neurological changes that result from blindness, as well as revealing the inner workings of the human brain. Specifically, modern imaging techniques enable us to examine how the brain adapts and “re-wires” itself as a result of changes in behavior, the environment, injury, or disease; a process referred to as neuroplasticity. Following an overview of commonly employed neuroimaging techniques, we discuss structural and functional neuroplastic brain changes associated with profound visual deprivation. In particular, we highlight how associated structural changes often occur within areas that process intact senses (such as hearing, touch, and smell) while functional changes tend to implicate areas of the brain normally ascribed to the processing of visual information. Evidence will primarily focus on profound blindness due to ocular cause, but related work in cerebral/cortical visual impairment (CVI) will also be discussed. The potential importance of these findings within the context of education and rehabilitation is proposed.
2014
Cattaneo, Zaira; Lega, Carlotta; Gardelli, Chiara; Merabet, Lotfi B; Cela-Conde, Camilo J; Nadal, Marcos
The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study Journal Article
In: Neuroimage, vol. 99, pp. 443–450, 2014, ISSN: 1095-9572.
@article{pmid24857715,
title = {The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study},
author = {Zaira Cattaneo and Carlotta Lega and Chiara Gardelli and Lotfi B Merabet and Camilo J Cela-Conde and Marcos Nadal},
doi = {10.1016/j.neuroimage.2014.05.037},
issn = {1095-9572},
year = {2014},
date = {2014-10-01},
journal = {Neuroimage},
volume = {99},
pages = {443--450},
abstract = {To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other.
Deer, Timothy R; Mekhail, Nagy; Petersen, Erika; Krames, Elliot; Staats, Peter; Pope, Jason; Saweris, Youssef; Lad, Shivanand P; Diwan, Sudhir; Falowski, Steven; Feler, Claudio; Slavin, Konstantin; Narouze, Samer; Merabet, Lotfi; Buvanendran, Asokumar; Fregni, Felipe; Wellington, Joshua; and, Robert M Levy
In: Neuromodulation, vol. 17, no. 6, pp. 551–70; discussion 570, 2014, ISSN: 1525-1403.
@article{pmid25112890,
title = {The appropriate use of neurostimulation: stimulation of the intracranial and extracranial space and head for chronic pain. Neuromodulation Appropriateness Consensus Committee},
author = {Timothy R Deer and Nagy Mekhail and Erika Petersen and Elliot Krames and Peter Staats and Jason Pope and Youssef Saweris and Shivanand P Lad and Sudhir Diwan and Steven Falowski and Claudio Feler and Konstantin Slavin and Samer Narouze and Lotfi Merabet and Asokumar Buvanendran and Felipe Fregni and Joshua Wellington and Robert M Levy and },
doi = {10.1111/ner.12215},
issn = {1525-1403},
year = {2014},
date = {2014-08-01},
journal = {Neuromodulation},
volume = {17},
number = {6},
pages = {551--70; discussion 570},
abstract = {INTRODUCTION: The International Neuromodulation Society (INS) has identified a need for evaluation and analysis of the practice of neurostimulation of the brain and extracranial nerves of the head to treat chronic pain.nnMETHODS: The INS board of directors chose an expert panel, the Neuromodulation Appropriateness Consensus Committee (NACC), to evaluate the peer-reviewed literature, current research, and clinical experience and to give guidance for the appropriate use of these methods. The literature searches involved key word searches in PubMed, EMBASE, and Google Scholar dated 1970-2013, which were graded and evaluated by the authors.nnRESULTS: The NACC found that evidence supports extracranial stimulation for facial pain, migraine, and scalp pain but is limited for intracranial neuromodulation. High cervical spinal cord stimulation is an evolving option for facial pain. Intracranial neurostimulation may be an excellent option to treat diseases of the nervous system, such as tremor and Parkinson's disease, and in the future, potentially Alzheimer's disease and traumatic brain injury, but current use of intracranial stimulation for pain should be seen as investigational.nnCONCLUSIONS: The NACC concludes that extracranial nerve stimulation should be considered in the algorithmic treatment of migraine and other disorders of the head. We should strive to perfect targets outside the cranium when treating pain, if at all possible.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
INTRODUCTION: The International Neuromodulation Society (INS) has identified a need for evaluation and analysis of the practice of neurostimulation of the brain and extracranial nerves of the head to treat chronic pain.nnMETHODS: The INS board of directors chose an expert panel, the Neuromodulation Appropriateness Consensus Committee (NACC), to evaluate the peer-reviewed literature, current research, and clinical experience and to give guidance for the appropriate use of these methods. The literature searches involved key word searches in PubMed, EMBASE, and Google Scholar dated 1970-2013, which were graded and evaluated by the authors.nnRESULTS: The NACC found that evidence supports extracranial stimulation for facial pain, migraine, and scalp pain but is limited for intracranial neuromodulation. High cervical spinal cord stimulation is an evolving option for facial pain. Intracranial neurostimulation may be an excellent option to treat diseases of the nervous system, such as tremor and Parkinson's disease, and in the future, potentially Alzheimer's disease and traumatic brain injury, but current use of intracranial stimulation for pain should be seen as investigational.nnCONCLUSIONS: The NACC concludes that extracranial nerve stimulation should be considered in the algorithmic treatment of migraine and other disorders of the head. We should strive to perfect targets outside the cranium when treating pain, if at all possible.
Bauer, Corinna M; Heidary, Gena; Koo, Bang-Bon; Killiany, Ronald J; Bex, Peter; Merabet, Lotfi B
In: J AAPOS, vol. 18, no. 4, pp. 398–401, 2014, ISSN: 1528-3933.
@article{pmid25087644,
title = {Abnormal white matter tractography of visual pathways detected by high-angular-resolution diffusion imaging (HARDI) corresponds to visual dysfunction in cortical/cerebral visual impairment},
author = {Corinna M Bauer and Gena Heidary and Bang-Bon Koo and Ronald J Killiany and Peter Bex and Lotfi B Merabet},
doi = {10.1016/j.jaapos.2014.03.004},
issn = {1528-3933},
year = {2014},
date = {2014-08-01},
journal = {J AAPOS},
volume = {18},
number = {4},
pages = {398--401},
abstract = {Cortical (cerebral) visual impairment (CVI) is characterized by visual dysfunction associated with damage to the optic radiations and/or visual cortex. Typically it results from pre- or perinatal hypoxic damage to postchiasmal visual structures and pathways. The neuroanatomical basis of this condition remains poorly understood, particularly with regard to how the resulting maldevelopment of visual processing pathways relates to observations in the clinical setting. We report our investigation of 2 young adults diagnosed with CVI and visual dysfunction characterized by difficulties related to visually guided attention and visuospatial processing. Using high-angular-resolution diffusion imaging (HARDI), we characterized and compared their individual white matter projections of the extrageniculo-striate visual system with a normal-sighted control. Compared to a sighted control, both CVI cases revealed a striking reduction in association fibers, including the inferior frontal-occipital fasciculus as well as superior and inferior longitudinal fasciculi. This reduction in fibers associated with the major pathways implicated in visual processing may provide a neuroanatomical basis for the visual dysfunctions observed in these patients.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cortical (cerebral) visual impairment (CVI) is characterized by visual dysfunction associated with damage to the optic radiations and/or visual cortex. Typically it results from pre- or perinatal hypoxic damage to postchiasmal visual structures and pathways. The neuroanatomical basis of this condition remains poorly understood, particularly with regard to how the resulting maldevelopment of visual processing pathways relates to observations in the clinical setting. We report our investigation of 2 young adults diagnosed with CVI and visual dysfunction characterized by difficulties related to visually guided attention and visuospatial processing. Using high-angular-resolution diffusion imaging (HARDI), we characterized and compared their individual white matter projections of the extrageniculo-striate visual system with a normal-sighted control. Compared to a sighted control, both CVI cases revealed a striking reduction in association fibers, including the inferior frontal-occipital fasciculus as well as superior and inferior longitudinal fasciculi. This reduction in fibers associated with the major pathways implicated in visual processing may provide a neuroanatomical basis for the visual dysfunctions observed in these patients.
Connell, Nyssa; Merabet, Lotfi B
Uncovering the connectivity of the brain in relation to novel vision rehabilitation strategies Miscellaneous
2014, ISSN: 1526-632X.
@misc{pmid24991035,
title = {Uncovering the connectivity of the brain in relation to novel vision rehabilitation strategies},
author = {Nyssa Connell and Lotfi B Merabet},
doi = {10.1212/WNL.0000000000000664},
issn = {1526-632X},
year = {2014},
date = {2014-08-01},
journal = {Neurology},
volume = {83},
number = {6},
pages = {484--485},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Halko, Mark A; Connors, Erin C; Sánchez, Jaime; Merabet, Lotfi B
Real world navigation independence in the early blind correlates with differential brain activity associated with virtual navigation Journal Article
In: Hum Brain Mapp, vol. 35, no. 6, pp. 2768–2778, 2014, ISSN: 1097-0193.
@article{pmid24027192,
title = {Real world navigation independence in the early blind correlates with differential brain activity associated with virtual navigation},
author = {Mark A Halko and Erin C Connors and Jaime Sánchez and Lotfi B Merabet},
doi = {10.1002/hbm.22365},
issn = {1097-0193},
year = {2014},
date = {2014-06-01},
journal = {Hum Brain Mapp},
volume = {35},
number = {6},
pages = {2768--2778},
abstract = {Navigating is a complex cognitive task that places high demands on spatial abilities, particularly in the absence of sight. Significant advances have been made in identifying the neural correlates associated with various aspects of this skill; however, how the brain is able to navigate in the absence of visual experience remains poorly understood. Furthermore, how neural network activity relates to the wide variability in navigational independence and skill in the blind population is also unknown. Using functional magnetic resonance imaging, we investigated the neural correlates of audio-based navigation within a large scale, indoor virtual environment in early profoundly blind participants with differing levels of spatial navigation independence (assessed by the Santa Barbara Sense of Direction scale). Performing path integration tasks in the virtual environment was associated with activation within areas of a core network implicated in navigation. Furthermore, we found a positive relationship between Santa Barbara Sense of Direction scores and activation within right temporal parietal junction during the planning and execution phases of the task. These findings suggest that differential navigational ability in the blind may be related to the utilization of different brain network structures. Further characterization of the factors that influence network activity may have important implications regarding how this skill is taught in the blind community.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Navigating is a complex cognitive task that places high demands on spatial abilities, particularly in the absence of sight. Significant advances have been made in identifying the neural correlates associated with various aspects of this skill; however, how the brain is able to navigate in the absence of visual experience remains poorly understood. Furthermore, how neural network activity relates to the wide variability in navigational independence and skill in the blind population is also unknown. Using functional magnetic resonance imaging, we investigated the neural correlates of audio-based navigation within a large scale, indoor virtual environment in early profoundly blind participants with differing levels of spatial navigation independence (assessed by the Santa Barbara Sense of Direction scale). Performing path integration tasks in the virtual environment was associated with activation within areas of a core network implicated in navigation. Furthermore, we found a positive relationship between Santa Barbara Sense of Direction scores and activation within right temporal parietal junction during the planning and execution phases of the task. These findings suggest that differential navigational ability in the blind may be related to the utilization of different brain network structures. Further characterization of the factors that influence network activity may have important implications regarding how this skill is taught in the blind community.
Connors, Erin C.; Chrastil, Elizabeth R.; Sánchez, Jaime; Merabet, Lotfi B.
In: Front. Hum. Neurosci., vol. 8, 2014, ISSN: 1662-5161.
@article{Connors2014,
title = {Virtual environments for the transfer of navigation skills in the blind: a comparison of directed instruction vs. video game based learning approaches},
author = {Erin C. Connors and Elizabeth R. Chrastil and Jaime Sánchez and Lotfi B. Merabet},
doi = {10.3389/fnhum.2014.00223},
issn = {1662-5161},
year = {2014},
date = {2014-05-01},
journal = {Front. Hum. Neurosci.},
volume = {8},
publisher = {Frontiers Media SA},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cattaneo, Zaira; Renzi, Chiara; Bona, Silvia; Merabet, Lotfi B; Carbon, Claus-Christian; Vecchi, Tomaso
Hemispheric asymmetry in discriminating faces differing for featural or configural (second-order relations) aspects Journal Article
In: Psychon Bull Rev, vol. 21, no. 2, pp. 363–369, 2014, ISSN: 1531-5320.
@article{pmid23888423,
title = {Hemispheric asymmetry in discriminating faces differing for featural or configural (second-order relations) aspects},
author = {Zaira Cattaneo and Chiara Renzi and Silvia Bona and Lotfi B Merabet and Claus-Christian Carbon and Tomaso Vecchi},
doi = {10.3758/s13423-013-0484-2},
issn = {1531-5320},
year = {2014},
date = {2014-04-01},
journal = {Psychon Bull Rev},
volume = {21},
number = {2},
pages = {363--369},
abstract = {The human capacity to discriminate among different faces relies on distinct parallel subprocesses, based either on the analysis of configural aspects or on the sequential analysis of the single elements of a face. A particular type of configural processing consists of considering whether two faces differ in terms of internal spacing among their features, referred to as second-order relations processing. Findings from electrophysiological, neuroimaging, and lesion studies suggest that, overall, configural processes rely more on the right hemisphere, whereas analysis of single features would involve more the left. However, results are not always consistent, and behavioral evidence for a right-hemisphere specialization in second-order relations processing is lacking. Here, we used divided visual field presentation to investigate the possible different contributions of the two hemispheres to face discrimination based on relational versus featural processing. Our data indicate a right-hemispheric specialization in relational processing of upright (but not inverted) faces. Furthermore, we provide evidence regarding the involvement of both the right and left hemispheres in the processing of faces differing for inner features, suggesting that both analytical and configural modes of processing are at play.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The human capacity to discriminate among different faces relies on distinct parallel subprocesses, based either on the analysis of configural aspects or on the sequential analysis of the single elements of a face. A particular type of configural processing consists of considering whether two faces differ in terms of internal spacing among their features, referred to as second-order relations processing. Findings from electrophysiological, neuroimaging, and lesion studies suggest that, overall, configural processes rely more on the right hemisphere, whereas analysis of single features would involve more the left. However, results are not always consistent, and behavioral evidence for a right-hemisphere specialization in second-order relations processing is lacking. Here, we used divided visual field presentation to investigate the possible different contributions of the two hemispheres to face discrimination based on relational versus featural processing. Our data indicate a right-hemispheric specialization in relational processing of upright (but not inverted) faces. Furthermore, we provide evidence regarding the involvement of both the right and left hemispheres in the processing of faces differing for inner features, suggesting that both analytical and configural modes of processing are at play.
Connors, Erin C.; Chrastil, Elizabeth R.; Sánchez, Jaime; Merabet, Lotfi B.
Action video game play and transfer of navigation and spatial cognition skills in adolescents who are blind Journal Article
In: Front. Hum. Neurosci., vol. 8, 2014, ISSN: 1662-5161.
@article{Connors2014b,
title = {Action video game play and transfer of navigation and spatial cognition skills in adolescents who are blind},
author = {Erin C. Connors and Elizabeth R. Chrastil and Jaime Sánchez and Lotfi B. Merabet},
doi = {10.3389/fnhum.2014.00133},
issn = {1662-5161},
year = {2014},
date = {2014-03-11},
journal = {Front. Hum. Neurosci.},
volume = {8},
publisher = {Frontiers Media SA},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Sánchez, Jaime; Campos, Márcia Borba; Espinoza, Matías; Merabet, Lotfi B.
Audio haptic videogaming for developing wayfinding skills in learners who are blind Journal Article
In: IUI, pp. 199-208, 2014.
@article{166976,
title = {Audio haptic videogaming for developing wayfinding skills in learners who are blind},
author = {Jaime Sánchez and Márcia Borba Campos and Matías Espinoza and Lotfi B. Merabet},
url = {http://dl.acm.org/citation.cfm?doid=2557500.2557519},
year = {2014},
date = {2014-01-01},
journal = {IUI},
pages = {199-208},
abstract = {Interactive digital technologies are currently being developed as a novel tool for education and skill development. Audiopolis is an audio and haptic based videogame designed for developing orientation and mobility (O&M) skills in people who are blind. We have evaluated the cognitive impact of videogame play on O&M skills by assessing performance on a series of behavioral tasks carried out in both indoor and outdoor virtual spaces. Our results demonstrate that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged learners who are blind. The impact of audio and haptic information on learning is also discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Interactive digital technologies are currently being developed as a novel tool for education and skill development. Audiopolis is an audio and haptic based videogame designed for developing orientation and mobility (O&M) skills in people who are blind. We have evaluated the cognitive impact of videogame play on O&M skills by assessing performance on a series of behavioral tasks carried out in both indoor and outdoor virtual spaces. Our results demonstrate that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged learners who are blind. The impact of audio and haptic information on learning is also discussed.
Sánchez, Jaime; Campos, Márcia Borba; Espinoza, Matías; Merabet, Lotfi B.
Audio haptic videogaming for developing wayfinding skills in learners who are blind Journal Article
In: IUI, pp. 199-208, 2014.
@article{166976b,
title = {Audio haptic videogaming for developing wayfinding skills in learners who are blind},
author = {Jaime Sánchez and Márcia Borba Campos and Matías Espinoza and Lotfi B. Merabet},
url = {http://dl.acm.org/citation.cfm?doid=2557500.2557519},
year = {2014},
date = {2014-01-01},
journal = {IUI},
pages = {199-208},
abstract = {Interactive digital technologies are currently being developed as a novel tool for education and skill development. Audiopolis is an audio and haptic based videogame designed for developing orientation and mobility (O&M) skills in people who are blind. We have evaluated the cognitive impact of videogame play on O&M skills by assessing performance on a series of behavioral tasks carried out in both indoor and outdoor virtual spaces. Our results demonstrate that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged learners who are blind. The impact of audio and haptic information on learning is also discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Interactive digital technologies are currently being developed as a novel tool for education and skill development. Audiopolis is an audio and haptic based videogame designed for developing orientation and mobility (O&M) skills in people who are blind. We have evaluated the cognitive impact of videogame play on O&M skills by assessing performance on a series of behavioral tasks carried out in both indoor and outdoor virtual spaces. Our results demonstrate that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged learners who are blind. The impact of audio and haptic information on learning is also discussed.
Connors, Erin C; Chrastil, Elizabeth R; Sánchez, Jaime; Merabet, Lotfi B
Action video game play and transfer of navigation and spatial cognition skills in adolescents who are blind Journal Article
In: Front Hum Neurosci, vol. 8, pp. 133, 2014, ISSN: 1662-5161.
@article{pmid24653690,
title = {Action video game play and transfer of navigation and spatial cognition skills in adolescents who are blind},
author = {Erin C Connors and Elizabeth R Chrastil and Jaime Sánchez and Lotfi B Merabet},
doi = {10.3389/fnhum.2014.00133},
issn = {1662-5161},
year = {2014},
date = {2014-01-01},
journal = {Front Hum Neurosci},
volume = {8},
pages = {133},
abstract = {For individuals who are blind, navigating independently in an unfamiliar environment represents a considerable challenge. Inspired by the rising popularity of video games, we have developed a novel approach to train navigation and spatial cognition skills in adolescents who are blind. Audio-based Environment Simulator (AbES) is a software application that allows for the virtual exploration of an existing building set in an action video game metaphor. Using this ludic-based approach to learning, we investigated the ability and efficacy of adolescents with early onset blindness to acquire spatial information gained from the exploration of a target virtual indoor environment. Following game play, participants were assessed on their ability to transfer and mentally manipulate acquired spatial information on a set of navigation tasks carried out in the real environment. Success in transfer of navigation skill performance was markedly high suggesting that interacting with AbES leads to the generation of an accurate spatial mental representation. Furthermore, there was a positive correlation between success in game play and navigation task performance. The role of virtual environments and gaming in the development of mental spatial representations is also discussed. We conclude that this game based learning approach can facilitate the transfer of spatial knowledge and further, can be used by individuals who are blind for the purposes of navigation in real-world environments.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
For individuals who are blind, navigating independently in an unfamiliar environment represents a considerable challenge. Inspired by the rising popularity of video games, we have developed a novel approach to train navigation and spatial cognition skills in adolescents who are blind. Audio-based Environment Simulator (AbES) is a software application that allows for the virtual exploration of an existing building set in an action video game metaphor. Using this ludic-based approach to learning, we investigated the ability and efficacy of adolescents with early onset blindness to acquire spatial information gained from the exploration of a target virtual indoor environment. Following game play, participants were assessed on their ability to transfer and mentally manipulate acquired spatial information on a set of navigation tasks carried out in the real environment. Success in transfer of navigation skill performance was markedly high suggesting that interacting with AbES leads to the generation of an accurate spatial mental representation. Furthermore, there was a positive correlation between success in game play and navigation task performance. The role of virtual environments and gaming in the development of mental spatial representations is also discussed. We conclude that this game based learning approach can facilitate the transfer of spatial knowledge and further, can be used by individuals who are blind for the purposes of navigation in real-world environments.
Kalia, Amy; Hopkins, Rose; Jin, David; Yazzolino, Lindsay; Verma, Svena; Merabet, Lotfi; Phillips, Flip; Sinha, Pawan
Perception of tactile graphics: embossings versus cutouts Journal Article
In: Multisens Res, vol. 27, no. 2, pp. 111–125, 2014, ISSN: 2213-4794.
@article{pmid25296474,
title = {Perception of tactile graphics: embossings versus cutouts},
author = {Amy Kalia and Rose Hopkins and David Jin and Lindsay Yazzolino and Svena Verma and Lotfi Merabet and Flip Phillips and Pawan Sinha},
doi = {10.1163/22134808-00002450},
issn = {2213-4794},
year = {2014},
date = {2014-01-01},
journal = {Multisens Res},
volume = {27},
number = {2},
pages = {111--125},
abstract = {Graphical information, such as illustrations, graphs, and diagrams, are an essential complement to text for conveying knowledge about the world. Although graphics can be communicated well via the visual modality, conveying this information via touch has proven to be challenging. The lack of easily comprehensible tactile graphics poses a problem for the blind. In this paper, we advance a hypothesis for the limited effectiveness of tactile graphics. The hypothesis contends that conventional graphics that rely upon embossings on two-dimensional surfaces do not allow the deployment of tactile exploratory procedures that are crucial for assessing global shape. Besides potentially accounting for some of the shortcomings of current approaches, this hypothesis also serves a prescriptive purpose by suggesting a different strategy for conveying graphical information via touch, one based on cutouts. We describe experiments demonstrating the greater effectiveness of this approach for conveying shape and identity information. These results hold the potential for creating more comprehensible tactile drawings for the visually impaired while also providing insights into shape estimation processes in the tactile modality.},
keywords = {},
pubstate = {published},
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Graphical information, such as illustrations, graphs, and diagrams, are an essential complement to text for conveying knowledge about the world. Although graphics can be communicated well via the visual modality, conveying this information via touch has proven to be challenging. The lack of easily comprehensible tactile graphics poses a problem for the blind. In this paper, we advance a hypothesis for the limited effectiveness of tactile graphics. The hypothesis contends that conventional graphics that rely upon embossings on two-dimensional surfaces do not allow the deployment of tactile exploratory procedures that are crucial for assessing global shape. Besides potentially accounting for some of the shortcomings of current approaches, this hypothesis also serves a prescriptive purpose by suggesting a different strategy for conveying graphical information via touch, one based on cutouts. We describe experiments demonstrating the greater effectiveness of this approach for conveying shape and identity information. These results hold the potential for creating more comprehensible tactile drawings for the visually impaired while also providing insights into shape estimation processes in the tactile modality.
Sánchez, Jaime; de Borba Campos, Marcia; Espinoza, Matías; Merabet, Lotfi B
Audio Haptic Videogaming for Developing Wayfinding Skills in Learners Who are Blind Journal Article
In: IUI, vol. 2014, pp. 199–208, 2014.
@article{pmid25485312,
title = {Audio Haptic Videogaming for Developing Wayfinding Skills in Learners Who are Blind},
author = {Jaime Sánchez and Marcia de Borba Campos and Matías Espinoza and Lotfi B Merabet},
doi = {10.1145/2557500.2557519},
year = {2014},
date = {2014-01-01},
journal = {IUI},
volume = {2014},
pages = {199--208},
abstract = {Interactive digital technologies are currently being developed as a novel tool for education and skill development. Audiopolis is an audio and haptic based videogame designed for developing orientation and mobility (O&M) skills in people who are blind. We have evaluated the cognitive impact of videogame play on O&M skills by assessing performance on a series of behavioral tasks carried out in both indoor and outdoor virtual spaces. Our results demonstrate that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged learners who are blind. The impact of audio and haptic information on learning is also discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Interactive digital technologies are currently being developed as a novel tool for education and skill development. Audiopolis is an audio and haptic based videogame designed for developing orientation and mobility (O&M) skills in people who are blind. We have evaluated the cognitive impact of videogame play on O&M skills by assessing performance on a series of behavioral tasks carried out in both indoor and outdoor virtual spaces. Our results demonstrate that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged learners who are blind. The impact of audio and haptic information on learning is also discussed.
Marques, Lucas Murrins; Lapenta, Olivia Morgan; Merabet, Lotfi B; Bolognini, Nadia; Boggio, Paulo Sérgio
Tuning and disrupting the brain-modulating the McGurk illusion with electrical stimulation Journal Article
In: Front Hum Neurosci, vol. 8, pp. 533, 2014, ISSN: 1662-5161.
@article{pmid25140136,
title = {Tuning and disrupting the brain-modulating the McGurk illusion with electrical stimulation},
author = {Lucas Murrins Marques and Olivia Morgan Lapenta and Lotfi B Merabet and Nadia Bolognini and Paulo Sérgio Boggio},
doi = {10.3389/fnhum.2014.00533},
issn = {1662-5161},
year = {2014},
date = {2014-01-01},
journal = {Front Hum Neurosci},
volume = {8},
pages = {533},
abstract = {In the so-called McGurk illusion, when the synchronized presentation of the visual stimulus /ga/ is paired with the auditory stimulus /ba/, people in general hear it as /da/. Multisensory integration processing underlying this illusion seems to occur within the Superior Temporal Sulcus (STS). Herein, we present evidence demonstrating that bilateral cathodal transcranial direct current stimulation (tDCS) of this area can decrease the McGurk illusion-type responses. Additionally, we show that the manipulation of this audio-visual integrated output occurs irrespective of the number of eye-fixations on the mouth of the speaker. Bilateral anodal tDCS of the Parietal Cortex also modulates the illusion, but in the opposite manner, inducing more illusion-type responses. This is the first demonstration of using non-invasive brain stimulation to modulate multisensory speech perception in an illusory context (i.e., both increasing and decreasing illusion-type responses to a verbal audio-visual integration task). These findings provide clear evidence that both the superior temporal and parietal areas contribute to multisensory integration processing related to speech perception. Specifically, STS seems fundamental for the temporal synchronization and integration of auditory and visual inputs. For its part, posterior parietal cortex (PPC) may adjust the arrival of incoming audio and visual information to STS thereby enhancing their interaction in this latter area.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the so-called McGurk illusion, when the synchronized presentation of the visual stimulus /ga/ is paired with the auditory stimulus /ba/, people in general hear it as /da/. Multisensory integration processing underlying this illusion seems to occur within the Superior Temporal Sulcus (STS). Herein, we present evidence demonstrating that bilateral cathodal transcranial direct current stimulation (tDCS) of this area can decrease the McGurk illusion-type responses. Additionally, we show that the manipulation of this audio-visual integrated output occurs irrespective of the number of eye-fixations on the mouth of the speaker. Bilateral anodal tDCS of the Parietal Cortex also modulates the illusion, but in the opposite manner, inducing more illusion-type responses. This is the first demonstration of using non-invasive brain stimulation to modulate multisensory speech perception in an illusory context (i.e., both increasing and decreasing illusion-type responses to a verbal audio-visual integration task). These findings provide clear evidence that both the superior temporal and parietal areas contribute to multisensory integration processing related to speech perception. Specifically, STS seems fundamental for the temporal synchronization and integration of auditory and visual inputs. For its part, posterior parietal cortex (PPC) may adjust the arrival of incoming audio and visual information to STS thereby enhancing their interaction in this latter area.
Lega, Carlotta; Cattaneo, Zaira; Merabet, Lotfi B; Vecchi, Tomaso; Cucchi, Silvia
The effect of musical expertise on the representation of space Journal Article
In: Front Hum Neurosci, vol. 8, pp. 250, 2014, ISSN: 1662-5161.
@article{pmid24795605,
title = {The effect of musical expertise on the representation of space},
author = {Carlotta Lega and Zaira Cattaneo and Lotfi B Merabet and Tomaso Vecchi and Silvia Cucchi},
doi = {10.3389/fnhum.2014.00250},
issn = {1662-5161},
year = {2014},
date = {2014-01-01},
journal = {Front Hum Neurosci},
volume = {8},
pages = {250},
abstract = {Consistent evidence suggests that pitch height may be represented in a spatial format, having both a vertical and a horizontal representation. The spatial representation of pitch height results into response compatibility effects for which high pitch tones are preferentially associated to up-right responses, and low pitch tones are preferentially associated to down-left responses (i.e., the Spatial-Musical Association of Response Codes (SMARC) effect), with the strength of these associations depending on individuals' musical skills. In this study we investigated whether listening to tones of different pitch affects the representation of external space, as assessed in a visual and haptic line bisection paradigm, in musicians and non musicians. Low and high pitch tones affected the bisection performance in musicians differently, both when pitch was relevant and irrelevant for the task, and in both the visual and the haptic modality. No effect of pitch height was observed on the bisection performance of non musicians. Moreover, our data also show that musicians present a (supramodal) rightward bisection bias in both the visual and the haptic modality, extending previous findings limited to the visual modality, and consistent with the idea that intense practice with musical notation and bimanual instrument training affects hemispheric lateralization.},
keywords = {},
pubstate = {published},
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Consistent evidence suggests that pitch height may be represented in a spatial format, having both a vertical and a horizontal representation. The spatial representation of pitch height results into response compatibility effects for which high pitch tones are preferentially associated to up-right responses, and low pitch tones are preferentially associated to down-left responses (i.e., the Spatial-Musical Association of Response Codes (SMARC) effect), with the strength of these associations depending on individuals' musical skills. In this study we investigated whether listening to tones of different pitch affects the representation of external space, as assessed in a visual and haptic line bisection paradigm, in musicians and non musicians. Low and high pitch tones affected the bisection performance in musicians differently, both when pitch was relevant and irrelevant for the task, and in both the visual and the haptic modality. No effect of pitch height was observed on the bisection performance of non musicians. Moreover, our data also show that musicians present a (supramodal) rightward bisection bias in both the visual and the haptic modality, extending previous findings limited to the visual modality, and consistent with the idea that intense practice with musical notation and bimanual instrument training affects hemispheric lateralization.
Connors, Erin C; Chrastil, Elizabeth R; Sánchez, Jaime; Merabet, Lotfi B
In: Front Hum Neurosci, vol. 8, pp. 223, 2014, ISSN: 1662-5161.
@article{pmid24822044,
title = {Virtual environments for the transfer of navigation skills in the blind: a comparison of directed instruction vs. video game based learning approaches},
author = {Erin C Connors and Elizabeth R Chrastil and Jaime Sánchez and Lotfi B Merabet},
doi = {10.3389/fnhum.2014.00223},
issn = {1662-5161},
year = {2014},
date = {2014-01-01},
journal = {Front Hum Neurosci},
volume = {8},
pages = {223},
abstract = {For profoundly blind individuals, navigating in an unfamiliar building can represent a significant challenge. We investigated the use of an audio-based, virtual environment called Audio-based Environment Simulator (AbES) that can be explored for the purposes of learning the layout of an unfamiliar, complex indoor environment. Furthermore, we compared two modes of interaction with AbES. In one group, blind participants implicitly learned the layout of a target environment while playing an exploratory, goal-directed video game. By comparison, a second group was explicitly taught the same layout following a standard route and instructions provided by a sighted facilitator. As a control, a third group interacted with AbES while playing an exploratory, goal-directed video game however, the explored environment did not correspond to the target layout. Following interaction with AbES, a series of route navigation tasks were carried out in the virtual and physical building represented in the training environment to assess the transfer of acquired spatial information. We found that participants from both modes of interaction were able to transfer the spatial knowledge gained as indexed by their successful route navigation performance. This transfer was not apparent in the control participants. Most notably, the game-based learning strategy was also associated with enhanced performance when participants were required to find alternate routes and short cuts within the target building suggesting that a ludic-based training approach may provide for a more flexible mental representation of the environment. Furthermore, outcome comparisons between early and late blind individuals suggested that greater prior visual experience did not have a significant effect on overall navigation performance following training. Finally, performance did not appear to be associated with other factors of interest such as age, gender, and verbal memory recall. We conclude that the highly interactive and immersive exploration of the virtual environment greatly engages a blind user to develop skills akin to positive near transfer of learning. Learning through a game play strategy appears to confer certain behavioral advantages with respect to how spatial information is acquired and ultimately manipulated for navigation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
For profoundly blind individuals, navigating in an unfamiliar building can represent a significant challenge. We investigated the use of an audio-based, virtual environment called Audio-based Environment Simulator (AbES) that can be explored for the purposes of learning the layout of an unfamiliar, complex indoor environment. Furthermore, we compared two modes of interaction with AbES. In one group, blind participants implicitly learned the layout of a target environment while playing an exploratory, goal-directed video game. By comparison, a second group was explicitly taught the same layout following a standard route and instructions provided by a sighted facilitator. As a control, a third group interacted with AbES while playing an exploratory, goal-directed video game however, the explored environment did not correspond to the target layout. Following interaction with AbES, a series of route navigation tasks were carried out in the virtual and physical building represented in the training environment to assess the transfer of acquired spatial information. We found that participants from both modes of interaction were able to transfer the spatial knowledge gained as indexed by their successful route navigation performance. This transfer was not apparent in the control participants. Most notably, the game-based learning strategy was also associated with enhanced performance when participants were required to find alternate routes and short cuts within the target building suggesting that a ludic-based training approach may provide for a more flexible mental representation of the environment. Furthermore, outcome comparisons between early and late blind individuals suggested that greater prior visual experience did not have a significant effect on overall navigation performance following training. Finally, performance did not appear to be associated with other factors of interest such as age, gender, and verbal memory recall. We conclude that the highly interactive and immersive exploration of the virtual environment greatly engages a blind user to develop skills akin to positive near transfer of learning. Learning through a game play strategy appears to confer certain behavioral advantages with respect to how spatial information is acquired and ultimately manipulated for navigation.
2013
Peters, Megan A K; Thompson, Benjamin; Merabet, Lotfi B; Wu, Allan D; Shams, Ladan
Anodal tDCS to V1 blocks visual perceptual learning consolidation Journal Article
In: Neuropsychologia, vol. 51, no. 7, pp. 1234–1239, 2013, ISSN: 1873-3514.
@article{pmid23562964,
title = {Anodal tDCS to V1 blocks visual perceptual learning consolidation},
author = {Megan A K Peters and Benjamin Thompson and Lotfi B Merabet and Allan D Wu and Ladan Shams},
doi = {10.1016/j.neuropsychologia.2013.03.013},
issn = {1873-3514},
year = {2013},
date = {2013-06-01},
journal = {Neuropsychologia},
volume = {51},
number = {7},
pages = {1234--1239},
abstract = {This study examined the effects of visual cortex transcranial direct current stimulation (tDCS) on visual processing and learning. Participants performed a contrast detection task on two consecutive days. Each session consisted of a baseline measurement followed by measurements made during active or sham stimulation. On the first day, one group received anodal stimulation to primary visual cortex (V1), while another received cathodal stimulation. Stimulation polarity was reversed for these groups on the second day. The third (control) group of subjects received sham stimulation on both days. No improvements or decrements in contrast sensitivity relative to the same-day baseline were observed during real tDCS, nor was any within-session learning trend observed. However, task performance improved significantly from Day 1 to Day 2 for the participants who received cathodal tDCS on Day 1 and for the sham group. No such improvement was found for the participants who received anodal stimulation on Day 1, indicating that anodal tDCS blocked overnight consolidation of visual learning, perhaps through engagement of inhibitory homeostatic plasticity mechanisms or alteration of the signal-to-noise ratio within stimulated cortex. These results show that applying tDCS to the visual cortex can modify consolidation of visual learning.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study examined the effects of visual cortex transcranial direct current stimulation (tDCS) on visual processing and learning. Participants performed a contrast detection task on two consecutive days. Each session consisted of a baseline measurement followed by measurements made during active or sham stimulation. On the first day, one group received anodal stimulation to primary visual cortex (V1), while another received cathodal stimulation. Stimulation polarity was reversed for these groups on the second day. The third (control) group of subjects received sham stimulation on both days. No improvements or decrements in contrast sensitivity relative to the same-day baseline were observed during real tDCS, nor was any within-session learning trend observed. However, task performance improved significantly from Day 1 to Day 2 for the participants who received cathodal tDCS on Day 1 and for the sham group. No such improvement was found for the participants who received anodal stimulation on Day 1, indicating that anodal tDCS blocked overnight consolidation of visual learning, perhaps through engagement of inhibitory homeostatic plasticity mechanisms or alteration of the signal-to-noise ratio within stimulated cortex. These results show that applying tDCS to the visual cortex can modify consolidation of visual learning.
Connors, Erin C; Yazzolino, Lindsay A; Sánchez, Jaime; Merabet, Lotfi B
Development of an audio-based virtual gaming environment to assist with navigation skills in the blind Journal Article
In: J Vis Exp, no. 73, 2013, ISSN: 1940-087X.
@article{pmid23568182,
title = {Development of an audio-based virtual gaming environment to assist with navigation skills in the blind},
author = {Erin C Connors and Lindsay A Yazzolino and Jaime Sánchez and Lotfi B Merabet},
doi = {10.3791/50272},
issn = {1940-087X},
year = {2013},
date = {2013-03-01},
journal = {J Vis Exp},
number = {73},
abstract = {Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio based cues and set within the context of a video game metaphor, users gather relevant spatial information regarding a building's layout. This allows the user to develop an accurate spatial cognitive map of a large-scale three-dimensional space that can be manipulated for the purposes of a real indoor navigation task. After game play, participants are then assessed on their ability to navigate within the target physical building represented in the game. Preliminary results suggest that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building as indexed by their performance on a series of navigation tasks. These tasks included path finding through the virtual and physical building, as well as a series of drop off tasks. We find that the immersive and highly interactive nature of the AbES software appears to greatly engage the blind user to actively explore the virtual environment. Applications of this approach may extend to larger populations of visually impaired individuals.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio based cues and set within the context of a video game metaphor, users gather relevant spatial information regarding a building's layout. This allows the user to develop an accurate spatial cognitive map of a large-scale three-dimensional space that can be manipulated for the purposes of a real indoor navigation task. After game play, participants are then assessed on their ability to navigate within the target physical building represented in the game. Preliminary results suggest that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building as indexed by their performance on a series of navigation tasks. These tasks included path finding through the virtual and physical building, as well as a series of drop off tasks. We find that the immersive and highly interactive nature of the AbES software appears to greatly engage the blind user to actively explore the virtual environment. Applications of this approach may extend to larger populations of visually impaired individuals.
Cattaneo, Zaira; Vecchi, Tomaso; Monegato, Maura; Pece, Alfredo; Merabet, Lotfi B; Carbon, Claus-Christian
Strabismic amblyopia affects relational but not featural and Gestalt processing of faces Journal Article
In: Vision Res, vol. 80, pp. 19–30, 2013, ISSN: 1878-5646.
@article{pmid23376210,
title = {Strabismic amblyopia affects relational but not featural and Gestalt processing of faces},
author = {Zaira Cattaneo and Tomaso Vecchi and Maura Monegato and Alfredo Pece and Lotfi B Merabet and Claus-Christian Carbon},
doi = {10.1016/j.visres.2013.01.007},
issn = {1878-5646},
year = {2013},
date = {2013-03-01},
journal = {Vision Res},
volume = {80},
pages = {19--30},
abstract = {The ability to identify faces is of critical importance for normal social interactions. Previous evidence suggests that early visual deprivation may impair certain aspects of face recognition. The effects of strabismic amblyopia on face processing have not been investigated previously. In this study, a group of individuals with amblyopia were administered two tasks known to selectively measure face detection based on a Gestalt representation of a face (Mooney faces task) and featural and relational processing of faces (Jane faces task). Our data show that--when relying on their amblyopic eye only - strabismic amblyopes perform as well as normally sighted individuals in face detection and recognition on the basis of their single features. However, they are significantly impaired in discriminating among different faces on the basis of the spacing of their single features (i.e., configural processing of relational information). Our findings are the first to demonstrate that strabismic amblyopia may cause specific deficits in face recognition, and add to previous reports characterizing visual perceptual deficits associated in amblyopia as high-level and not only as low-level processing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The ability to identify faces is of critical importance for normal social interactions. Previous evidence suggests that early visual deprivation may impair certain aspects of face recognition. The effects of strabismic amblyopia on face processing have not been investigated previously. In this study, a group of individuals with amblyopia were administered two tasks known to selectively measure face detection based on a Gestalt representation of a face (Mooney faces task) and featural and relational processing of faces (Jane faces task). Our data show that--when relying on their amblyopic eye only - strabismic amblyopes perform as well as normally sighted individuals in face detection and recognition on the basis of their single features. However, they are significantly impaired in discriminating among different faces on the basis of the spacing of their single features (i.e., configural processing of relational information). Our findings are the first to demonstrate that strabismic amblyopia may cause specific deficits in face recognition, and add to previous reports characterizing visual perceptual deficits associated in amblyopia as high-level and not only as low-level processing.
Bolognini, Nadia; Convento, Silvia; Rossetti, Angela; Merabet, Lotfi B
Multisensory processing after a brain damage: clues on post-injury crossmodal plasticity from neuropsychology Journal Article
In: Neurosci Biobehav Rev, vol. 37, no. 3, pp. 269–278, 2013, ISSN: 1873-7528.
@article{pmid23253947,
title = {Multisensory processing after a brain damage: clues on post-injury crossmodal plasticity from neuropsychology},
author = {Nadia Bolognini and Silvia Convento and Angela Rossetti and Lotfi B Merabet},
doi = {10.1016/j.neubiorev.2012.12.006},
issn = {1873-7528},
year = {2013},
date = {2013-03-01},
journal = {Neurosci Biobehav Rev},
volume = {37},
number = {3},
pages = {269--278},
abstract = {Current neuropsychological evidence demonstrates that damage to sensory-specific and heteromodal areas of the brain not only disrupts the ability of combining sensory information from multiple sources, but can also cause altered multisensory experiences. On the other hand, there is also evidence of behavioural benefits induced by spared multisensory mechanisms. Thus, crossmodal plasticity can be viewed in both an adaptive and maladaptive context. The emerging view is that different crossmodal plastic changes can result following damage to sensory-specific and heteromodal areas, with post-injury crossmodal plasticity representing an attempt of a multisensory system to reconnect the various senses and by-pass injured areas. Changes can be considered adaptive when there is compensation for the lesion-induced sensory impairment. Conversely, it may prove maladaptive when atypical or even illusory multisensory experiences are generated as a result of re-arranged multisensory networks. This theoretical framework posits new intriguing questions for neuropsychological research and places greater emphasis on the study of multisensory phenomena within the context of damage to large-scale brain networks, rather than just focal damage alone.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Current neuropsychological evidence demonstrates that damage to sensory-specific and heteromodal areas of the brain not only disrupts the ability of combining sensory information from multiple sources, but can also cause altered multisensory experiences. On the other hand, there is also evidence of behavioural benefits induced by spared multisensory mechanisms. Thus, crossmodal plasticity can be viewed in both an adaptive and maladaptive context. The emerging view is that different crossmodal plastic changes can result following damage to sensory-specific and heteromodal areas, with post-injury crossmodal plasticity representing an attempt of a multisensory system to reconnect the various senses and by-pass injured areas. Changes can be considered adaptive when there is compensation for the lesion-induced sensory impairment. Conversely, it may prove maladaptive when atypical or even illusory multisensory experiences are generated as a result of re-arranged multisensory networks. This theoretical framework posits new intriguing questions for neuropsychological research and places greater emphasis on the study of multisensory phenomena within the context of damage to large-scale brain networks, rather than just focal damage alone.
Cattaneo, Zaira; Vecchi, Tomaso; Fantino, Micaela; Herbert, Andrew M; Merabet, Lotfi B
The effect of vertical and horizontal symmetry on memory for tactile patterns in late blind individuals Journal Article
In: Atten Percept Psychophys, vol. 75, no. 2, pp. 375–382, 2013, ISSN: 1943-393X.
@article{pmid23150215,
title = {The effect of vertical and horizontal symmetry on memory for tactile patterns in late blind individuals},
author = {Zaira Cattaneo and Tomaso Vecchi and Micaela Fantino and Andrew M Herbert and Lotfi B Merabet},
doi = {10.3758/s13414-012-0393-x},
issn = {1943-393X},
year = {2013},
date = {2013-02-01},
journal = {Atten Percept Psychophys},
volume = {75},
number = {2},
pages = {375--382},
abstract = {Visual stimuli that exhibit vertical symmetry are easier to remember than stimuli symmetric along other axes, an advantage that extends to the haptic modality as well. Critically, the vertical symmetry memory advantage has not been found in early blind individuals, despite their overall superior memory, as compared with sighted individuals, and the presence of an overall advantage for identifying symmetric over asymmetric patterns. The absence of the vertical axis memory advantage in the early blind may depend on their total lack of visual experience or on the effect of prolonged visual deprivation. To disentangle this issue, in this study, we measured the ability of late blind individuals to remember tactile spatial patterns that were either vertically or horizontally symmetric or asymmetric. Late blind participants showed better memory performance for symmetric patterns. An additional advantage for the vertical axis of symmetry over the horizontal one was reported, but only for patterns presented in the frontal plane. In the horizontal plane, no difference was observed between vertical and horizontal symmetric patterns, due to the latter being recalled particularly well. These results are discussed in terms of the influence of the spatial reference frame adopted during exploration. Overall, our data suggest that prior visual experience is sufficient to drive the vertical symmetry memory advantage, at least when an external reference frame based on geocentric cues (i.e., gravity) is adopted.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Visual stimuli that exhibit vertical symmetry are easier to remember than stimuli symmetric along other axes, an advantage that extends to the haptic modality as well. Critically, the vertical symmetry memory advantage has not been found in early blind individuals, despite their overall superior memory, as compared with sighted individuals, and the presence of an overall advantage for identifying symmetric over asymmetric patterns. The absence of the vertical axis memory advantage in the early blind may depend on their total lack of visual experience or on the effect of prolonged visual deprivation. To disentangle this issue, in this study, we measured the ability of late blind individuals to remember tactile spatial patterns that were either vertically or horizontally symmetric or asymmetric. Late blind participants showed better memory performance for symmetric patterns. An additional advantage for the vertical axis of symmetry over the horizontal one was reported, but only for patterns presented in the frontal plane. In the horizontal plane, no difference was observed between vertical and horizontal symmetric patterns, due to the latter being recalled particularly well. These results are discussed in terms of the influence of the spatial reference frame adopted during exploration. Overall, our data suggest that prior visual experience is sufficient to drive the vertical symmetry memory advantage, at least when an external reference frame based on geocentric cues (i.e., gravity) is adopted.
Sánchez, Jaime; Campos, Marcia Borba; Espinoza, Matías; Merabet, Lotfi B.
Accessibility for people who are blind in public transportation systems Journal Article
In: IUI, pp. 753-756, 2013.
@article{166991,
title = {Accessibility for people who are blind in public transportation systems},
author = {Jaime Sánchez and Marcia Borba Campos and Matías Espinoza and Lotfi B. Merabet},
url = {http://dl.acm.org/citation.cfm?doid=2494091.2496002},
year = {2013},
date = {2013-01-01},
journal = {IUI},
pages = {753-756},
abstract = {In order to support access for people who are blind to modes of transportation in the city, it is necessary to design technological tools that allow them to carry out activities safely, autonomously, and functionally. In this context, three mobile orientation and mobility support systems were designed for people who are blind to aid in their effective navigation using various modes of transportation in the city of Santiago, Chile. This work presents the most significant implications of the use of these systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In order to support access for people who are blind to modes of transportation in the city, it is necessary to design technological tools that allow them to carry out activities safely, autonomously, and functionally. In this context, three mobile orientation and mobility support systems were designed for people who are blind to aid in their effective navigation using various modes of transportation in the city of Santiago, Chile. This work presents the most significant implications of the use of these systems.
Sánchez, Jaime; Espinoza, Matías; de Borba Campos, Marcia; Merabet, Lotfi B
Enhancing Orientation and Mobility Skills in Learners who are Blind through Video gaming Journal Article
In: Creat Cognit, vol. 2013, pp. 353–356, 2013.
@article{pmid25505797,
title = {Enhancing Orientation and Mobility Skills in Learners who are Blind through Video gaming},
author = {Jaime Sánchez and Matías Espinoza and Marcia de Borba Campos and Lotfi B Merabet},
doi = {10.1145/2466627.2466673},
year = {2013},
date = {2013-01-01},
journal = {Creat Cognit},
volume = {2013},
pages = {353--356},
abstract = {In this work we present the results of the cognitive impact evaluation regarding the use of Audiopolis, an audio and/or haptic-based videogame. The software has been designed, developed and evaluated for the purpose of developing orientation and mobility (O&M) skills in blind users. The videogame was evaluated through cognitive tasks performed by a sample of 12 learners. The results demonstrated that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged blind learners.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work we present the results of the cognitive impact evaluation regarding the use of Audiopolis, an audio and/or haptic-based videogame. The software has been designed, developed and evaluated for the purpose of developing orientation and mobility (O&M) skills in blind users. The videogame was evaluated through cognitive tasks performed by a sample of 12 learners. The results demonstrated that the use of Audiopolis had a positive impact on the development and use of O&M skills in school-aged blind learners.
Volz, Magdalena Sarah; Suarez-Contreras, Vanessa; Mendonca, Mariana E; Pinheiro, Fernando Santos; Merabet, Lotfi B; Fregni, Felipe
Effects of sensory behavioral tasks on pain threshold and cortical excitability Journal Article
In: PLoS One, vol. 8, no. 1, pp. e52968, 2013, ISSN: 1932-6203.
@article{pmid23301010,
title = {Effects of sensory behavioral tasks on pain threshold and cortical excitability},
author = {Magdalena Sarah Volz and Vanessa Suarez-Contreras and Mariana E Mendonca and Fernando Santos Pinheiro and Lotfi B Merabet and Felipe Fregni},
doi = {10.1371/journal.pone.0052968},
issn = {1932-6203},
year = {2013},
date = {2013-01-01},
journal = {PLoS One},
volume = {8},
number = {1},
pages = {e52968},
abstract = {BACKGROUND/OBJECTIVE: Transcutaneous electrical stimulation has been proven to modulate nervous system activity, leading to changes in pain perception, via the peripheral sensory system, in a bottom up approach. We tested whether different sensory behavioral tasks induce significant effects in pain processing and whether these changes correlate with cortical plasticity.nnMETHODOLOGY/PRINCIPAL FINDINGS: This randomized parallel designed experiment included forty healthy right-handed males. Three different somatosensory tasks, including learning tasks with and without visual feedback and simple somatosensory input, were tested on pressure pain threshold and motor cortex excitability using transcranial magnetic stimulation (TMS). Sensory tasks induced hand-specific pain modulation effects. They increased pain thresholds of the left hand (which was the target to the sensory tasks) and decreased them in the right hand. TMS showed that somatosensory input decreased cortical excitability, as indexed by reduced MEP amplitudes and increased SICI. Although somatosensory tasks similarly altered pain thresholds and cortical excitability, there was no significant correlation between these variables and only the visual feedback task showed significant somatosensory learning.nnCONCLUSIONS/SIGNIFICANCE: Lack of correlation between cortical excitability and pain thresholds and lack of differential effects across tasks, but significant changes in pain thresholds suggest that analgesic effects of somatosensory tasks are not primarily associated with motor cortical neural mechanisms, thus, suggesting that subcortical neural circuits and/or spinal cord are involved with the observed effects. Identifying the neural mechanisms of somatosensory stimulation on pain may open novel possibilities for combining different targeted therapies for pain control.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND/OBJECTIVE: Transcutaneous electrical stimulation has been proven to modulate nervous system activity, leading to changes in pain perception, via the peripheral sensory system, in a bottom up approach. We tested whether different sensory behavioral tasks induce significant effects in pain processing and whether these changes correlate with cortical plasticity.nnMETHODOLOGY/PRINCIPAL FINDINGS: This randomized parallel designed experiment included forty healthy right-handed males. Three different somatosensory tasks, including learning tasks with and without visual feedback and simple somatosensory input, were tested on pressure pain threshold and motor cortex excitability using transcranial magnetic stimulation (TMS). Sensory tasks induced hand-specific pain modulation effects. They increased pain thresholds of the left hand (which was the target to the sensory tasks) and decreased them in the right hand. TMS showed that somatosensory input decreased cortical excitability, as indexed by reduced MEP amplitudes and increased SICI. Although somatosensory tasks similarly altered pain thresholds and cortical excitability, there was no significant correlation between these variables and only the visual feedback task showed significant somatosensory learning.nnCONCLUSIONS/SIGNIFICANCE: Lack of correlation between cortical excitability and pain thresholds and lack of differential effects across tasks, but significant changes in pain thresholds suggest that analgesic effects of somatosensory tasks are not primarily associated with motor cortical neural mechanisms, thus, suggesting that subcortical neural circuits and/or spinal cord are involved with the observed effects. Identifying the neural mechanisms of somatosensory stimulation on pain may open novel possibilities for combining different targeted therapies for pain control.
2012
Plow, Ela B; Obretenova, Souzana N; Jackson, Mary Lou; Merabet, Lotfi B.
Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation Journal Article
In: Neuromodulation, vol. 15, no. 4, pp. 367-73, 2012, ISSN: 1525-1403.
@article{55116,
title = {Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation},
author = {Ela B Plow and Souzana N Obretenova and Mary Lou Jackson and Lotfi B. Merabet},
doi = {10.1111/j.1525-1403.2012.00440.x},
issn = {1525-1403},
year = {2012},
date = {2012-07-01},
journal = {Neuromodulation},
volume = {15},
number = {4},
pages = {367-73},
abstract = {OBJECTIVES: We have previously reported that transcranial direct current stimulation (tDCS) delivered to the occipital cortex enhances visual functional recovery when combined with three months of computer-based rehabilitative training in patients with hemianopia. The principal objective of this study was to evaluate the temporal sequence of effects of tDCS on visual recovery as they appear over the course of training and across different indicators of visual function.
METHODS: Primary objective outcome measures were 1) shifts in visual field border and 2) stimulus detection accuracy within the affected hemifield. These were compared between patients randomized to either vision restoration therapy (VRT) combined with active tDCS or VRT paired with sham tDCS. Training comprised two half-hour sessions, three times a week for three months. Primary outcome measures were collected at baseline (pretest), monthly interim intervals, and at posttest (three months). As secondary outcome measures, contrast sensitivity and reading performance were collected at pretest and posttest time points only.
RESULTS: Active tDCS combined with VRT accelerated the recovery of stimulus detection as between-group differences appeared within the first month of training. In contrast, a shift in the visual field border was only evident at posttest (after three months of training). tDCS did not affect contrast sensitivity or reading performance.
CONCLUSIONS: These results suggest that tDCS may differentially affect the magnitude and sequence of visual recovery in a manner that is task specific to the type of visual rehabilitative training strategy employed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVES: We have previously reported that transcranial direct current stimulation (tDCS) delivered to the occipital cortex enhances visual functional recovery when combined with three months of computer-based rehabilitative training in patients with hemianopia. The principal objective of this study was to evaluate the temporal sequence of effects of tDCS on visual recovery as they appear over the course of training and across different indicators of visual function.
METHODS: Primary objective outcome measures were 1) shifts in visual field border and 2) stimulus detection accuracy within the affected hemifield. These were compared between patients randomized to either vision restoration therapy (VRT) combined with active tDCS or VRT paired with sham tDCS. Training comprised two half-hour sessions, three times a week for three months. Primary outcome measures were collected at baseline (pretest), monthly interim intervals, and at posttest (three months). As secondary outcome measures, contrast sensitivity and reading performance were collected at pretest and posttest time points only.
RESULTS: Active tDCS combined with VRT accelerated the recovery of stimulus detection as between-group differences appeared within the first month of training. In contrast, a shift in the visual field border was only evident at posttest (after three months of training). tDCS did not affect contrast sensitivity or reading performance.
CONCLUSIONS: These results suggest that tDCS may differentially affect the magnitude and sequence of visual recovery in a manner that is task specific to the type of visual rehabilitative training strategy employed.
METHODS: Primary objective outcome measures were 1) shifts in visual field border and 2) stimulus detection accuracy within the affected hemifield. These were compared between patients randomized to either vision restoration therapy (VRT) combined with active tDCS or VRT paired with sham tDCS. Training comprised two half-hour sessions, three times a week for three months. Primary outcome measures were collected at baseline (pretest), monthly interim intervals, and at posttest (three months). As secondary outcome measures, contrast sensitivity and reading performance were collected at pretest and posttest time points only.
RESULTS: Active tDCS combined with VRT accelerated the recovery of stimulus detection as between-group differences appeared within the first month of training. In contrast, a shift in the visual field border was only evident at posttest (after three months of training). tDCS did not affect contrast sensitivity or reading performance.
CONCLUSIONS: These results suggest that tDCS may differentially affect the magnitude and sequence of visual recovery in a manner that is task specific to the type of visual rehabilitative training strategy employed.
Plow, Ela B; Obretenova, Souzana N; Fregni, Felipe; Pascual-Leone, Alvaro; Merabet, Lotfi B.
Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation Journal Article
In: Neurorehabil Neural Repair, vol. 26, no. 6, pp. 616-26, 2012, ISSN: 1552-6844.
@article{55121,
title = {Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation},
author = {Ela B Plow and Souzana N Obretenova and Felipe Fregni and Alvaro Pascual-Leone and Lotfi B. Merabet},
doi = {10.1177/1545968311431963},
issn = {1552-6844},
year = {2012},
date = {2012-07-01},
journal = {Neurorehabil Neural Repair},
volume = {26},
number = {6},
pages = {616-26},
abstract = {BACKGROUND: Vision Restoration Therapy (VRT) aims to improve visual field function by systematically training regions of residual vision associated with the activity of suboptimal firing neurons within the occipital cortex. Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability.
OBJECTIVE: Assess the possible efficacy of tDCS combined with VRT.
METHODS: The authors conducted a randomized, double-blind, demonstration-of-concept pilot study where participants were assigned to either VRT and tDCS or VRT and sham. The anode was placed over the occipital pole to target both affected and unaffected lobes. One hour training sessions were carried out 3 times per week for 3 months in a laboratory. Outcome measures included objective and subjective changes in visual field, recording of visual fixation performance, and vision-related activities of daily living (ADLs) and quality of life (QOL).
RESULTS: Although 12 participants were enrolled, only 8 could be analyzed. The VRT and tDCS group demonstrated significantly greater expansion in visual field and improvement on ADLs compared with the VRT and sham group. Contrary to expectations, subjective perception of visual field change was greater in the VRT and sham group. QOL did not change for either group. The observed changes in visual field were unrelated to compensatory eye movements, as shown with fixation monitoring.
CONCLUSIONS: The combination of occipital cortical tDCS with visual field rehabilitation appears to enhance visual functional outcomes compared with visual rehabilitation alone. TDCS may enhance inherent mechanisms of plasticity associated with training.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Vision Restoration Therapy (VRT) aims to improve visual field function by systematically training regions of residual vision associated with the activity of suboptimal firing neurons within the occipital cortex. Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability.
OBJECTIVE: Assess the possible efficacy of tDCS combined with VRT.
METHODS: The authors conducted a randomized, double-blind, demonstration-of-concept pilot study where participants were assigned to either VRT and tDCS or VRT and sham. The anode was placed over the occipital pole to target both affected and unaffected lobes. One hour training sessions were carried out 3 times per week for 3 months in a laboratory. Outcome measures included objective and subjective changes in visual field, recording of visual fixation performance, and vision-related activities of daily living (ADLs) and quality of life (QOL).
RESULTS: Although 12 participants were enrolled, only 8 could be analyzed. The VRT and tDCS group demonstrated significantly greater expansion in visual field and improvement on ADLs compared with the VRT and sham group. Contrary to expectations, subjective perception of visual field change was greater in the VRT and sham group. QOL did not change for either group. The observed changes in visual field were unrelated to compensatory eye movements, as shown with fixation monitoring.
CONCLUSIONS: The combination of occipital cortical tDCS with visual field rehabilitation appears to enhance visual functional outcomes compared with visual rehabilitation alone. TDCS may enhance inherent mechanisms of plasticity associated with training.
OBJECTIVE: Assess the possible efficacy of tDCS combined with VRT.
METHODS: The authors conducted a randomized, double-blind, demonstration-of-concept pilot study where participants were assigned to either VRT and tDCS or VRT and sham. The anode was placed over the occipital pole to target both affected and unaffected lobes. One hour training sessions were carried out 3 times per week for 3 months in a laboratory. Outcome measures included objective and subjective changes in visual field, recording of visual fixation performance, and vision-related activities of daily living (ADLs) and quality of life (QOL).
RESULTS: Although 12 participants were enrolled, only 8 could be analyzed. The VRT and tDCS group demonstrated significantly greater expansion in visual field and improvement on ADLs compared with the VRT and sham group. Contrary to expectations, subjective perception of visual field change was greater in the VRT and sham group. QOL did not change for either group. The observed changes in visual field were unrelated to compensatory eye movements, as shown with fixation monitoring.
CONCLUSIONS: The combination of occipital cortical tDCS with visual field rehabilitation appears to enhance visual functional outcomes compared with visual rehabilitation alone. TDCS may enhance inherent mechanisms of plasticity associated with training.
Brunoni, Andre Russowsky; Nitsche, Michael A; Bolognini, Nadia; Bikson, Marom; Wagner, Tim; Merabet, Lotfi; Edwards, Dylan J; Valero-Cabre, Antoni; Rotenberg, Alexander; Pascual-Leone, Alvaro; Ferrucci, Roberta; Priori, Alberto; Boggio, Paulo Sergio; Fregni, Felipe
Clinical research with transcranial direct current stimulation (tDCS): challenges and future directions. Journal Article
In: Brain Stimul, vol. 5, no. 3, pp. 175-95, 2012, ISSN: 1935-861X.
@article{55126,
title = {Clinical research with transcranial direct current stimulation (tDCS): challenges and future directions.},
author = {Andre Russowsky Brunoni and Michael A Nitsche and Nadia Bolognini and Marom Bikson and Tim Wagner and Lotfi Merabet and Dylan J Edwards and Antoni Valero-Cabre and Alexander Rotenberg and Alvaro Pascual-Leone and Roberta Ferrucci and Alberto Priori and Paulo Sergio Boggio and Felipe Fregni},
doi = {10.1016/j.brs.2011.03.002},
issn = {1935-861X},
year = {2012},
date = {2012-07-01},
journal = {Brain Stimul},
volume = {5},
number = {3},
pages = {175-95},
abstract = {BACKGROUND: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past 10 years, tDCS physiologic mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodologic, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them. METHODS: We convened a workgroup of researchers in the field to review, discuss, and provide updates and key challenges of tDCS use in clinical research. MAIN FINDINGS/DISCUSSION: We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (1) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (2) methodologic aspects related to the clinical research of tDCS as divided according to study phase (ie, preclinical, phase I, phase II, and phase III studies); (3) ethical and regulatory concerns; and (4) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past 10 years, tDCS physiologic mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodologic, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them. METHODS: We convened a workgroup of researchers in the field to review, discuss, and provide updates and key challenges of tDCS use in clinical research. MAIN FINDINGS/DISCUSSION: We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (1) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (2) methodologic aspects related to the clinical research of tDCS as divided according to study phase (ie, preclinical, phase I, phase II, and phase III studies); (3) ethical and regulatory concerns; and (4) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS.
Fregni, Felipe; Merabet, Lotfi B
Bench to clinical translational applications of noninvasive brain stimulation Journal Article
In: Neuromodulation, vol. 15, no. 4, pp. 281–282, 2012, ISSN: 1525-1403.
@article{pmid22882243,
title = {Bench to clinical translational applications of noninvasive brain stimulation},
author = {Felipe Fregni and Lotfi B Merabet},
doi = {10.1111/j.1525-1403.2012.00485.x},
issn = {1525-1403},
year = {2012},
date = {2012-07-01},
journal = {Neuromodulation},
volume = {15},
number = {4},
pages = {281--282},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Brunoni, Andre Russowsky; Nitsche, Michael A; Bolognini, Nadia; Bikson, Marom; Wagner, Tim; Merabet, Lotfi; Edwards, Dylan J; Valero-Cabre, Antoni; Rotenberg, Alexander; Pascual-Leone, Alvaro; Ferrucci, Roberta; Priori, Alberto; Boggio, Paulo Sergio; Fregni, Felipe
Clinical research with transcranial direct current stimulation (tDCS): challenges and future directions Journal Article
In: Brain Stimul, vol. 5, no. 3, pp. 175–195, 2012, ISSN: 1876-4754.
@article{pmid22037126,
title = {Clinical research with transcranial direct current stimulation (tDCS): challenges and future directions},
author = {Andre Russowsky Brunoni and Michael A Nitsche and Nadia Bolognini and Marom Bikson and Tim Wagner and Lotfi Merabet and Dylan J Edwards and Antoni Valero-Cabre and Alexander Rotenberg and Alvaro Pascual-Leone and Roberta Ferrucci and Alberto Priori and Paulo Sergio Boggio and Felipe Fregni},
doi = {10.1016/j.brs.2011.03.002},
issn = {1876-4754},
year = {2012},
date = {2012-07-01},
journal = {Brain Stimul},
volume = {5},
number = {3},
pages = {175--195},
abstract = {BACKGROUND: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past 10 years, tDCS physiologic mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodologic, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them.nnMETHODS: We convened a workgroup of researchers in the field to review, discuss, and provide updates and key challenges of tDCS use in clinical research.nnMAIN FINDINGS/DISCUSSION: We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (1) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (2) methodologic aspects related to the clinical research of tDCS as divided according to study phase (ie, preclinical, phase I, phase II, and phase III studies); (3) ethical and regulatory concerns; and (4) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity, direct current to cortical areas facilitating or inhibiting spontaneous neuronal activity. In the past 10 years, tDCS physiologic mechanisms of action have been intensively investigated giving support for the investigation of its applications in clinical neuropsychiatry and rehabilitation. However, new methodologic, ethical, and regulatory issues emerge when translating the findings of preclinical and phase I studies into phase II and III clinical studies. The aim of this comprehensive review is to discuss the key challenges of this process and possible methods to address them.nnMETHODS: We convened a workgroup of researchers in the field to review, discuss, and provide updates and key challenges of tDCS use in clinical research.nnMAIN FINDINGS/DISCUSSION: We reviewed several basic and clinical studies in the field and identified potential limitations, taking into account the particularities of the technique. We review and discuss the findings into four topics: (1) mechanisms of action of tDCS, parameters of use and computer-based human brain modeling investigating electric current fields and magnitude induced by tDCS; (2) methodologic aspects related to the clinical research of tDCS as divided according to study phase (ie, preclinical, phase I, phase II, and phase III studies); (3) ethical and regulatory concerns; and (4) future directions regarding novel approaches, novel devices, and future studies involving tDCS. Finally, we propose some alternative methods to facilitate clinical research on tDCS.
Bikson, Marom; Rahman, Asif; Datta, Abhishek; Fregni, Felipe; Merabet, Lotfi
High-resolution modeling assisted design of customized and individualized transcranial direct current stimulation protocols Journal Article
In: Neuromodulation, vol. 15, no. 4, pp. 306–315, 2012, ISSN: 1525-1403.
@article{pmid22780230,
title = {High-resolution modeling assisted design of customized and individualized transcranial direct current stimulation protocols},
author = {Marom Bikson and Asif Rahman and Abhishek Datta and Felipe Fregni and Lotfi Merabet},
doi = {10.1111/j.1525-1403.2012.00481.x},
issn = {1525-1403},
year = {2012},
date = {2012-07-01},
journal = {Neuromodulation},
volume = {15},
number = {4},
pages = {306--315},
abstract = {OBJECTIVES: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity currents facilitating or inhibiting spontaneous neuronal activity. tDCS is attractive since dose is readily adjustable by simply changing electrode number, position, size, shape, and current. In the recent past, computational models have been developed with increased precision with the goal to help customize tDCS dose. The aim of this review is to discuss the incorporation of high-resolution patient-specific computer modeling to guide and optimize tDCS.nnMETHODS: In this review, we discuss the following topics: 1) The clinical motivation and rationale for models of transcranial stimulation is considered pivotal in order to leverage the flexibility of neuromodulation; 2) the protocols and the workflow for developing high-resolution models; 3) the technical challenges and limitations of interpreting modeling predictions; and 4) real cases merging modeling and clinical data illustrating the impact of computational models on the rational design of rehabilitative electrotherapy.nnCONCLUSIONS: Though modeling for noninvasive brain stimulation is still in its development phase, it is predicted that with increased validation, dissemination, simplification, and democratization of modeling tools, computational forward models of neuromodulation will become useful tools to guide the optimization of clinical electrotherapy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVES: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity currents facilitating or inhibiting spontaneous neuronal activity. tDCS is attractive since dose is readily adjustable by simply changing electrode number, position, size, shape, and current. In the recent past, computational models have been developed with increased precision with the goal to help customize tDCS dose. The aim of this review is to discuss the incorporation of high-resolution patient-specific computer modeling to guide and optimize tDCS.nnMETHODS: In this review, we discuss the following topics: 1) The clinical motivation and rationale for models of transcranial stimulation is considered pivotal in order to leverage the flexibility of neuromodulation; 2) the protocols and the workflow for developing high-resolution models; 3) the technical challenges and limitations of interpreting modeling predictions; and 4) real cases merging modeling and clinical data illustrating the impact of computational models on the rational design of rehabilitative electrotherapy.nnCONCLUSIONS: Though modeling for noninvasive brain stimulation is still in its development phase, it is predicted that with increased validation, dissemination, simplification, and democratization of modeling tools, computational forward models of neuromodulation will become useful tools to guide the optimization of clinical electrotherapy.
Plow, Ela B; Obretenova, Souzana N; Jackson, Mary Lou; Merabet, Lotfi B
Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation Journal Article
In: Neuromodulation, vol. 15, no. 4, pp. 367–373, 2012, ISSN: 1525-1403.
@article{pmid22376226,
title = {Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation},
author = {Ela B Plow and Souzana N Obretenova and Mary Lou Jackson and Lotfi B Merabet},
doi = {10.1111/j.1525-1403.2012.00440.x},
issn = {1525-1403},
year = {2012},
date = {2012-07-01},
journal = {Neuromodulation},
volume = {15},
number = {4},
pages = {367--373},
abstract = {OBJECTIVES: We have previously reported that transcranial direct current stimulation (tDCS) delivered to the occipital cortex enhances visual functional recovery when combined with three months of computer-based rehabilitative training in patients with hemianopia. The principal objective of this study was to evaluate the temporal sequence of effects of tDCS on visual recovery as they appear over the course of training and across different indicators of visual function.nnMETHODS: Primary objective outcome measures were 1) shifts in visual field border and 2) stimulus detection accuracy within the affected hemifield. These were compared between patients randomized to either vision restoration therapy (VRT) combined with active tDCS or VRT paired with sham tDCS. Training comprised two half-hour sessions, three times a week for three months. Primary outcome measures were collected at baseline (pretest), monthly interim intervals, and at posttest (three months). As secondary outcome measures, contrast sensitivity and reading performance were collected at pretest and posttest time points only.nnRESULTS: Active tDCS combined with VRT accelerated the recovery of stimulus detection as between-group differences appeared within the first month of training. In contrast, a shift in the visual field border was only evident at posttest (after three months of training). tDCS did not affect contrast sensitivity or reading performance.nnCONCLUSIONS: These results suggest that tDCS may differentially affect the magnitude and sequence of visual recovery in a manner that is task specific to the type of visual rehabilitative training strategy employed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVES: We have previously reported that transcranial direct current stimulation (tDCS) delivered to the occipital cortex enhances visual functional recovery when combined with three months of computer-based rehabilitative training in patients with hemianopia. The principal objective of this study was to evaluate the temporal sequence of effects of tDCS on visual recovery as they appear over the course of training and across different indicators of visual function.nnMETHODS: Primary objective outcome measures were 1) shifts in visual field border and 2) stimulus detection accuracy within the affected hemifield. These were compared between patients randomized to either vision restoration therapy (VRT) combined with active tDCS or VRT paired with sham tDCS. Training comprised two half-hour sessions, three times a week for three months. Primary outcome measures were collected at baseline (pretest), monthly interim intervals, and at posttest (three months). As secondary outcome measures, contrast sensitivity and reading performance were collected at pretest and posttest time points only.nnRESULTS: Active tDCS combined with VRT accelerated the recovery of stimulus detection as between-group differences appeared within the first month of training. In contrast, a shift in the visual field border was only evident at posttest (after three months of training). tDCS did not affect contrast sensitivity or reading performance.nnCONCLUSIONS: These results suggest that tDCS may differentially affect the magnitude and sequence of visual recovery in a manner that is task specific to the type of visual rehabilitative training strategy employed.
Plow, Ela B; Obretenova, Souzana N; Fregni, Felipe; Pascual-Leone, Alvaro; Merabet, Lotfi B
Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation Journal Article
In: Neurorehabil Neural Repair, vol. 26, no. 6, pp. 616–626, 2012, ISSN: 1552-6844.
@article{pmid22291042,
title = {Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation},
author = {Ela B Plow and Souzana N Obretenova and Felipe Fregni and Alvaro Pascual-Leone and Lotfi B Merabet},
doi = {10.1177/1545968311431963},
issn = {1552-6844},
year = {2012},
date = {2012-01-01},
journal = {Neurorehabil Neural Repair},
volume = {26},
number = {6},
pages = {616--626},
abstract = {BACKGROUND: Vision Restoration Therapy (VRT) aims to improve visual field function by systematically training regions of residual vision associated with the activity of suboptimal firing neurons within the occipital cortex. Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability.nnOBJECTIVE: Assess the possible efficacy of tDCS combined with VRT.nnMETHODS: The authors conducted a randomized, double-blind, demonstration-of-concept pilot study where participants were assigned to either VRT and tDCS or VRT and sham. The anode was placed over the occipital pole to target both affected and unaffected lobes. One hour training sessions were carried out 3 times per week for 3 months in a laboratory. Outcome measures included objective and subjective changes in visual field, recording of visual fixation performance, and vision-related activities of daily living (ADLs) and quality of life (QOL).nnRESULTS: Although 12 participants were enrolled, only 8 could be analyzed. The VRT and tDCS group demonstrated significantly greater expansion in visual field and improvement on ADLs compared with the VRT and sham group. Contrary to expectations, subjective perception of visual field change was greater in the VRT and sham group. QOL did not change for either group. The observed changes in visual field were unrelated to compensatory eye movements, as shown with fixation monitoring.nnCONCLUSIONS: The combination of occipital cortical tDCS with visual field rehabilitation appears to enhance visual functional outcomes compared with visual rehabilitation alone. TDCS may enhance inherent mechanisms of plasticity associated with training.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: Vision Restoration Therapy (VRT) aims to improve visual field function by systematically training regions of residual vision associated with the activity of suboptimal firing neurons within the occipital cortex. Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability.nnOBJECTIVE: Assess the possible efficacy of tDCS combined with VRT.nnMETHODS: The authors conducted a randomized, double-blind, demonstration-of-concept pilot study where participants were assigned to either VRT and tDCS or VRT and sham. The anode was placed over the occipital pole to target both affected and unaffected lobes. One hour training sessions were carried out 3 times per week for 3 months in a laboratory. Outcome measures included objective and subjective changes in visual field, recording of visual fixation performance, and vision-related activities of daily living (ADLs) and quality of life (QOL).nnRESULTS: Although 12 participants were enrolled, only 8 could be analyzed. The VRT and tDCS group demonstrated significantly greater expansion in visual field and improvement on ADLs compared with the VRT and sham group. Contrary to expectations, subjective perception of visual field change was greater in the VRT and sham group. QOL did not change for either group. The observed changes in visual field were unrelated to compensatory eye movements, as shown with fixation monitoring.nnCONCLUSIONS: The combination of occipital cortical tDCS with visual field rehabilitation appears to enhance visual functional outcomes compared with visual rehabilitation alone. TDCS may enhance inherent mechanisms of plasticity associated with training.
Merabet, Lotfi B; Connors, Erin C; Halko, Mark A; Sánchez, Jaime
Teaching the blind to find their way by playing video games Journal Article
In: PLoS One, vol. 7, no. 9, pp. e44958, 2012, ISSN: 1932-6203.
@article{pmid23028703,
title = {Teaching the blind to find their way by playing video games},
author = {Lotfi B Merabet and Erin C Connors and Mark A Halko and Jaime Sánchez},
doi = {10.1371/journal.pone.0044958},
issn = {1932-6203},
year = {2012},
date = {2012-01-01},
journal = {PLoS One},
volume = {7},
number = {9},
pages = {e44958},
abstract = {Computer based video games are receiving great interest as a means to learn and acquire new skills. As a novel approach to teaching navigation skills in the blind, we have developed Audio-based Environment Simulator (AbES); a virtual reality environment set within the context of a video game metaphor. Despite the fact that participants were naïve to the overall purpose of the software, we found that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building using audio based cues alone. This was confirmed by a series of behavioral performance tests designed to assess the transfer of acquired spatial information to a large-scale, real-world indoor navigation task. Furthermore, learning the spatial layout through a goal directed gaming strategy allowed for the mental manipulation of spatial information as evidenced by enhanced navigation performance when compared to an explicit route learning strategy. We conclude that the immersive and highly interactive nature of the software greatly engages the blind user to actively explore the virtual environment. This in turn generates an accurate sense of a large-scale three-dimensional space and facilitates the learning and transfer of navigation skills to the physical world.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Computer based video games are receiving great interest as a means to learn and acquire new skills. As a novel approach to teaching navigation skills in the blind, we have developed Audio-based Environment Simulator (AbES); a virtual reality environment set within the context of a video game metaphor. Despite the fact that participants were naïve to the overall purpose of the software, we found that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building using audio based cues alone. This was confirmed by a series of behavioral performance tests designed to assess the transfer of acquired spatial information to a large-scale, real-world indoor navigation task. Furthermore, learning the spatial layout through a goal directed gaming strategy allowed for the mental manipulation of spatial information as evidenced by enhanced navigation performance when compared to an explicit route learning strategy. We conclude that the immersive and highly interactive nature of the software greatly engages the blind user to actively explore the virtual environment. This in turn generates an accurate sense of a large-scale three-dimensional space and facilitates the learning and transfer of navigation skills to the physical world.
2011
Plow, Ela B; Obretenova, Souzana N; Halko, Mark A; Kenkel, Sigrid; Jackson, Mary Lou; Pascual-Leone, Alvaro; Merabet, Lotfi B.
In: PM R, vol. 3, no. 9, pp. 825-35, 2011, ISSN: 1934-1563.
@article{55131,
title = {Combining visual rehabilitative training and noninvasive brain stimulation to enhance visual function in patients with hemianopia: a comparative case study},
author = {Ela B Plow and Souzana N Obretenova and Mark A Halko and Sigrid Kenkel and Mary Lou Jackson and Alvaro Pascual-Leone and Lotfi B. Merabet},
doi = {10.1016/j.pmrj.2011.05.026},
issn = {1934-1563},
year = {2011},
date = {2011-09-01},
journal = {PM R},
volume = {3},
number = {9},
pages = {825-35},
abstract = {OBJECTIVE: To standardize a protocol for promoting visual rehabilitative outcomes in post-stroke hemianopia by combining occipital cortical transcranial direct current stimulation (tDCS) with Vision Restoration Therapy (VRT).
DESIGN: A comparative case study assessing feasibility and safety.
SETTING: A controlled laboratory setting.
PATIENTS: Two patients, both with right hemianopia after occipital stroke damage. METHODS AND OUTCOME MEASUREMENTS: Both patients underwent an identical VRT protocol that lasted 3 months (30 minutes, twice a day, 3 days per week). In patient 1, anodal tDCS was delivered to the occipital cortex during VRT training, whereas in patient 2 sham tDCS with VRT was performed. The primary outcome, visual field border, was defined objectively by using high-resolution perimetry. Secondary outcomes included subjective characterization of visual deficit and functional surveys that assessed performance on activities of daily living. For patient 1, the neural correlates of visual recovery were also investigated, by using functional magnetic resonance imaging.
RESULTS: Delivery of combined tDCS with VRT was feasible and safe. High-resolution perimetry revealed a greater shift in visual field border for patient 1 versus patient 2. Patient 1 also showed greater recovery of function in activities of daily living. Contrary to the expectation, patient 2 perceived greater subjective improvement in visual field despite objective high-resolution perimetry results that indicated otherwise. In patient 1, visual function recovery was associated with functional magnetic resonance imaging activity in surviving peri-lesional and bilateral higher-order visual areas.
CONCLUSIONS: Results of preliminary case comparisons suggest that occipital cortical tDCS may enhance recovery of visual function associated with concurrent VRT through visual cortical reorganization. Future studies may benefit from incorporating protocol refinements such as those described here, which include global capture of function, control for potential confounds, and investigation of underlying neural substrates of recovery.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVE: To standardize a protocol for promoting visual rehabilitative outcomes in post-stroke hemianopia by combining occipital cortical transcranial direct current stimulation (tDCS) with Vision Restoration Therapy (VRT).
DESIGN: A comparative case study assessing feasibility and safety.
SETTING: A controlled laboratory setting.
PATIENTS: Two patients, both with right hemianopia after occipital stroke damage. METHODS AND OUTCOME MEASUREMENTS: Both patients underwent an identical VRT protocol that lasted 3 months (30 minutes, twice a day, 3 days per week). In patient 1, anodal tDCS was delivered to the occipital cortex during VRT training, whereas in patient 2 sham tDCS with VRT was performed. The primary outcome, visual field border, was defined objectively by using high-resolution perimetry. Secondary outcomes included subjective characterization of visual deficit and functional surveys that assessed performance on activities of daily living. For patient 1, the neural correlates of visual recovery were also investigated, by using functional magnetic resonance imaging.
RESULTS: Delivery of combined tDCS with VRT was feasible and safe. High-resolution perimetry revealed a greater shift in visual field border for patient 1 versus patient 2. Patient 1 also showed greater recovery of function in activities of daily living. Contrary to the expectation, patient 2 perceived greater subjective improvement in visual field despite objective high-resolution perimetry results that indicated otherwise. In patient 1, visual function recovery was associated with functional magnetic resonance imaging activity in surviving peri-lesional and bilateral higher-order visual areas.
CONCLUSIONS: Results of preliminary case comparisons suggest that occipital cortical tDCS may enhance recovery of visual function associated with concurrent VRT through visual cortical reorganization. Future studies may benefit from incorporating protocol refinements such as those described here, which include global capture of function, control for potential confounds, and investigation of underlying neural substrates of recovery.
DESIGN: A comparative case study assessing feasibility and safety.
SETTING: A controlled laboratory setting.
PATIENTS: Two patients, both with right hemianopia after occipital stroke damage. METHODS AND OUTCOME MEASUREMENTS: Both patients underwent an identical VRT protocol that lasted 3 months (30 minutes, twice a day, 3 days per week). In patient 1, anodal tDCS was delivered to the occipital cortex during VRT training, whereas in patient 2 sham tDCS with VRT was performed. The primary outcome, visual field border, was defined objectively by using high-resolution perimetry. Secondary outcomes included subjective characterization of visual deficit and functional surveys that assessed performance on activities of daily living. For patient 1, the neural correlates of visual recovery were also investigated, by using functional magnetic resonance imaging.
RESULTS: Delivery of combined tDCS with VRT was feasible and safe. High-resolution perimetry revealed a greater shift in visual field border for patient 1 versus patient 2. Patient 1 also showed greater recovery of function in activities of daily living. Contrary to the expectation, patient 2 perceived greater subjective improvement in visual field despite objective high-resolution perimetry results that indicated otherwise. In patient 1, visual function recovery was associated with functional magnetic resonance imaging activity in surviving peri-lesional and bilateral higher-order visual areas.
CONCLUSIONS: Results of preliminary case comparisons suggest that occipital cortical tDCS may enhance recovery of visual function associated with concurrent VRT through visual cortical reorganization. Future studies may benefit from incorporating protocol refinements such as those described here, which include global capture of function, control for potential confounds, and investigation of underlying neural substrates of recovery.
Plow, Ela B; Obretenova, Souzana N; Halko, Mark A; Kenkel, Sigrid; Jackson, Mary Lou; Pascual-Leone, Alvaro; Merabet, Lotfi B
In: PM R, vol. 3, no. 9, pp. 825–835, 2011, ISSN: 1934-1563.
@article{pmid21944300,
title = {Combining visual rehabilitative training and noninvasive brain stimulation to enhance visual function in patients with hemianopia: a comparative case study},
author = {Ela B Plow and Souzana N Obretenova and Mark A Halko and Sigrid Kenkel and Mary Lou Jackson and Alvaro Pascual-Leone and Lotfi B Merabet},
doi = {10.1016/j.pmrj.2011.05.026},
issn = {1934-1563},
year = {2011},
date = {2011-09-01},
journal = {PM R},
volume = {3},
number = {9},
pages = {825--835},
abstract = {OBJECTIVE: To standardize a protocol for promoting visual rehabilitative outcomes in post-stroke hemianopia by combining occipital cortical transcranial direct current stimulation (tDCS) with Vision Restoration Therapy (VRT).nnDESIGN: A comparative case study assessing feasibility and safety.nnSETTING: A controlled laboratory setting.nnPATIENTS: Two patients, both with right hemianopia after occipital stroke damage. METHODS AND OUTCOME MEASUREMENTS: Both patients underwent an identical VRT protocol that lasted 3 months (30 minutes, twice a day, 3 days per week). In patient 1, anodal tDCS was delivered to the occipital cortex during VRT training, whereas in patient 2 sham tDCS with VRT was performed. The primary outcome, visual field border, was defined objectively by using high-resolution perimetry. Secondary outcomes included subjective characterization of visual deficit and functional surveys that assessed performance on activities of daily living. For patient 1, the neural correlates of visual recovery were also investigated, by using functional magnetic resonance imaging.nnRESULTS: Delivery of combined tDCS with VRT was feasible and safe. High-resolution perimetry revealed a greater shift in visual field border for patient 1 versus patient 2. Patient 1 also showed greater recovery of function in activities of daily living. Contrary to the expectation, patient 2 perceived greater subjective improvement in visual field despite objective high-resolution perimetry results that indicated otherwise. In patient 1, visual function recovery was associated with functional magnetic resonance imaging activity in surviving peri-lesional and bilateral higher-order visual areas.nnCONCLUSIONS: Results of preliminary case comparisons suggest that occipital cortical tDCS may enhance recovery of visual function associated with concurrent VRT through visual cortical reorganization. Future studies may benefit from incorporating protocol refinements such as those described here, which include global capture of function, control for potential confounds, and investigation of underlying neural substrates of recovery.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
OBJECTIVE: To standardize a protocol for promoting visual rehabilitative outcomes in post-stroke hemianopia by combining occipital cortical transcranial direct current stimulation (tDCS) with Vision Restoration Therapy (VRT).nnDESIGN: A comparative case study assessing feasibility and safety.nnSETTING: A controlled laboratory setting.nnPATIENTS: Two patients, both with right hemianopia after occipital stroke damage. METHODS AND OUTCOME MEASUREMENTS: Both patients underwent an identical VRT protocol that lasted 3 months (30 minutes, twice a day, 3 days per week). In patient 1, anodal tDCS was delivered to the occipital cortex during VRT training, whereas in patient 2 sham tDCS with VRT was performed. The primary outcome, visual field border, was defined objectively by using high-resolution perimetry. Secondary outcomes included subjective characterization of visual deficit and functional surveys that assessed performance on activities of daily living. For patient 1, the neural correlates of visual recovery were also investigated, by using functional magnetic resonance imaging.nnRESULTS: Delivery of combined tDCS with VRT was feasible and safe. High-resolution perimetry revealed a greater shift in visual field border for patient 1 versus patient 2. Patient 1 also showed greater recovery of function in activities of daily living. Contrary to the expectation, patient 2 perceived greater subjective improvement in visual field despite objective high-resolution perimetry results that indicated otherwise. In patient 1, visual function recovery was associated with functional magnetic resonance imaging activity in surviving peri-lesional and bilateral higher-order visual areas.nnCONCLUSIONS: Results of preliminary case comparisons suggest that occipital cortical tDCS may enhance recovery of visual function associated with concurrent VRT through visual cortical reorganization. Future studies may benefit from incorporating protocol refinements such as those described here, which include global capture of function, control for potential confounds, and investigation of underlying neural substrates of recovery.
Halko, M A; Datta, A; Plow, E B; Scaturro, J; Bikson, M; Merabet, L B
Neuroplastic changes following rehabilitative training correlate with regional electrical field induced with tDCS Journal Article
In: Neuroimage, vol. 57, no. 3, pp. 885–891, 2011, ISSN: 1095-9572.
@article{pmid21620985,
title = {Neuroplastic changes following rehabilitative training correlate with regional electrical field induced with tDCS},
author = {M A Halko and A Datta and E B Plow and J Scaturro and M Bikson and L B Merabet},
doi = {10.1016/j.neuroimage.2011.05.026},
issn = {1095-9572},
year = {2011},
date = {2011-08-01},
journal = {Neuroimage},
volume = {57},
number = {3},
pages = {885--891},
abstract = {Transcranial direct current stimulation (tDCS) has recently emerged as a promising approach to enhance neurorehabilitative outcomes. However, little is known about how the local electrical field generated by tDCS relates to underlying neuroplastic changes and behavior. To address this question, we present a case study analysis of an individual with hemianopia due to stroke and who benefited from a combined visual rehabilitation training and tDCS treatment program. Activation associated with a visual motion perception task (obtained by functional magnetic resonance imaging; fMRI) was used to characterize local changes in brain activity at baseline and after training. Individualized, high-resolution electrical field modeling reproducing precise cerebral and lesioned tissue geometry, predicted distortions of current flow in peri-lesional areas and diffuse clusters of peak electric fields. Using changes in fMRI signal as an index of cortical recovery, correlations to the electrical field map were determined. Significant correlations between the electrical field and change in fMRI signal were region specific including cortical areas under the anode electrode and peri-lesional visual areas. These patterns were consistent with effective tDCS facilitated rehabilitation. We describe the methodology used to analyze tDCS mechanisms through combined fMRI and computational modeling with the ultimate goal of developing a rationale for individualized therapy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Transcranial direct current stimulation (tDCS) has recently emerged as a promising approach to enhance neurorehabilitative outcomes. However, little is known about how the local electrical field generated by tDCS relates to underlying neuroplastic changes and behavior. To address this question, we present a case study analysis of an individual with hemianopia due to stroke and who benefited from a combined visual rehabilitation training and tDCS treatment program. Activation associated with a visual motion perception task (obtained by functional magnetic resonance imaging; fMRI) was used to characterize local changes in brain activity at baseline and after training. Individualized, high-resolution electrical field modeling reproducing precise cerebral and lesioned tissue geometry, predicted distortions of current flow in peri-lesional areas and diffuse clusters of peak electric fields. Using changes in fMRI signal as an index of cortical recovery, correlations to the electrical field map were determined. Significant correlations between the electrical field and change in fMRI signal were region specific including cortical areas under the anode electrode and peri-lesional visual areas. These patterns were consistent with effective tDCS facilitated rehabilitation. We describe the methodology used to analyze tDCS mechanisms through combined fMRI and computational modeling with the ultimate goal of developing a rationale for individualized therapy.
Merabet, Lotfi B
Building the bionic eye: an emerging reality and opportunity Journal Article
In: Prog Brain Res, vol. 192, pp. 3–15, 2011, ISSN: 1875-7855.
@article{pmid21763515,
title = {Building the bionic eye: an emerging reality and opportunity},
author = {Lotfi B Merabet},
doi = {10.1016/B978-0-444-53355-5.00001-4},
issn = {1875-7855},
year = {2011},
date = {2011-01-01},
journal = {Prog Brain Res},
volume = {192},
pages = {3--15},
abstract = {Once the topic of folklore and science fiction, the notion of restoring vision to the blind is now approaching a tractable reality. Technological advances have inspired numerous multidisciplinary groups worldwide to develop visual neuroprosthetic devices that could potentially provide useful vision and improve the quality of life of profoundly blind individuals. While a variety of approaches and designs are being pursued, they all share a common principle of creating visual percepts through the stimulation of visual neural elements using appropriate patterns of electrical stimulation. Human clinical trials are now well underway and initial results have been met with a balance of excitement and cautious optimism. As remaining technical and surgical challenges continue to be solved and clinical trials move forward, we now enter a phase of development that requires careful consideration of a new set of issues. Establishing appropriate patient selection criteria, methods of evaluating long-term performance and effectiveness, and strategies to rehabilitate implanted patients will all need to be considered in order to achieve optimal outcomes and establish these devices as viable therapeutic options.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Once the topic of folklore and science fiction, the notion of restoring vision to the blind is now approaching a tractable reality. Technological advances have inspired numerous multidisciplinary groups worldwide to develop visual neuroprosthetic devices that could potentially provide useful vision and improve the quality of life of profoundly blind individuals. While a variety of approaches and designs are being pursued, they all share a common principle of creating visual percepts through the stimulation of visual neural elements using appropriate patterns of electrical stimulation. Human clinical trials are now well underway and initial results have been met with a balance of excitement and cautious optimism. As remaining technical and surgical challenges continue to be solved and clinical trials move forward, we now enter a phase of development that requires careful consideration of a new set of issues. Establishing appropriate patient selection criteria, methods of evaluating long-term performance and effectiveness, and strategies to rehabilitate implanted patients will all need to be considered in order to achieve optimal outcomes and establish these devices as viable therapeutic options.
2010
Bolognini, Nadia; Senna, Irene; Maravita, Angelo; Pascual-Leone, Alvaro; Merabet, Lotfi B.
Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity Journal Article
In: Neurosci Lett, vol. 477, no. 3, pp. 109-14, 2010, ISSN: 1872-7972.
@article{55146,
title = {Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity},
author = {Nadia Bolognini and Irene Senna and Angelo Maravita and Alvaro Pascual-Leone and Lotfi B. Merabet},
doi = {10.1016/j.neulet.2010.04.044},
issn = {1872-7972},
year = {2010},
date = {2010-06-01},
journal = {Neurosci Lett},
volume = {477},
number = {3},
pages = {109-14},
abstract = {Multisensory integration of information from different sensory modalities is an essential component of perception. Neurophysiological studies have revealed that audiovisual interactions occur early in time and even within sensory cortical areas believed to be modality-specific. Here we investigated the effect of auditory stimuli on visual perception of phosphenes induced by transcranial magnetic stimulation (TMS) delivered to the occipital visual cortex. TMS applied at subthreshold intensity led to the perception of phosphenes when coupled with an auditory stimulus presented within close spatiotemporal congruency at the expected retinotopic location of the phosphene percept. The effect was maximal when the auditory stimulus preceded the occipital TMS pulse by 40 ms. Follow-up experiments confirmed a high degree of temporal and spatial specificity of this facilitatory effect. Furthermore, audiovisual facilitation was only present at subthreshold TMS intensity for the phosphenes, suggesting that suboptimal levels of excitability within unisensory cortices may be better suited for enhanced crossmodal interactions. Overall, our findings reveal early auditory-visual interactions due to the enhancement of visual cortical excitability by auditory stimuli. These interactions may reflect an underlying anatomical connectivity between unisensory cortices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Multisensory integration of information from different sensory modalities is an essential component of perception. Neurophysiological studies have revealed that audiovisual interactions occur early in time and even within sensory cortical areas believed to be modality-specific. Here we investigated the effect of auditory stimuli on visual perception of phosphenes induced by transcranial magnetic stimulation (TMS) delivered to the occipital visual cortex. TMS applied at subthreshold intensity led to the perception of phosphenes when coupled with an auditory stimulus presented within close spatiotemporal congruency at the expected retinotopic location of the phosphene percept. The effect was maximal when the auditory stimulus preceded the occipital TMS pulse by 40 ms. Follow-up experiments confirmed a high degree of temporal and spatial specificity of this facilitatory effect. Furthermore, audiovisual facilitation was only present at subthreshold TMS intensity for the phosphenes, suggesting that suboptimal levels of excitability within unisensory cortices may be better suited for enhanced crossmodal interactions. Overall, our findings reveal early auditory-visual interactions due to the enhancement of visual cortical excitability by auditory stimuli. These interactions may reflect an underlying anatomical connectivity between unisensory cortices.
Bolognini, Nadia; Senna, Irene; Maravita, Angelo; Pascual-Leone, Alvaro; Merabet, Lotfi B
Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity Journal Article
In: Neurosci Lett, vol. 477, no. 3, pp. 109–114, 2010, ISSN: 1872-7972.
@article{pmid20430065,
title = {Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity},
author = {Nadia Bolognini and Irene Senna and Angelo Maravita and Alvaro Pascual-Leone and Lotfi B Merabet},
doi = {10.1016/j.neulet.2010.04.044},
issn = {1872-7972},
year = {2010},
date = {2010-06-01},
journal = {Neurosci Lett},
volume = {477},
number = {3},
pages = {109--114},
abstract = {Multisensory integration of information from different sensory modalities is an essential component of perception. Neurophysiological studies have revealed that audiovisual interactions occur early in time and even within sensory cortical areas believed to be modality-specific. Here we investigated the effect of auditory stimuli on visual perception of phosphenes induced by transcranial magnetic stimulation (TMS) delivered to the occipital visual cortex. TMS applied at subthreshold intensity led to the perception of phosphenes when coupled with an auditory stimulus presented within close spatiotemporal congruency at the expected retinotopic location of the phosphene percept. The effect was maximal when the auditory stimulus preceded the occipital TMS pulse by 40 ms. Follow-up experiments confirmed a high degree of temporal and spatial specificity of this facilitatory effect. Furthermore, audiovisual facilitation was only present at subthreshold TMS intensity for the phosphenes, suggesting that suboptimal levels of excitability within unisensory cortices may be better suited for enhanced crossmodal interactions. Overall, our findings reveal early auditory-visual interactions due to the enhancement of visual cortical excitability by auditory stimuli. These interactions may reflect an underlying anatomical connectivity between unisensory cortices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Multisensory integration of information from different sensory modalities is an essential component of perception. Neurophysiological studies have revealed that audiovisual interactions occur early in time and even within sensory cortical areas believed to be modality-specific. Here we investigated the effect of auditory stimuli on visual perception of phosphenes induced by transcranial magnetic stimulation (TMS) delivered to the occipital visual cortex. TMS applied at subthreshold intensity led to the perception of phosphenes when coupled with an auditory stimulus presented within close spatiotemporal congruency at the expected retinotopic location of the phosphene percept. The effect was maximal when the auditory stimulus preceded the occipital TMS pulse by 40 ms. Follow-up experiments confirmed a high degree of temporal and spatial specificity of this facilitatory effect. Furthermore, audiovisual facilitation was only present at subthreshold TMS intensity for the phosphenes, suggesting that suboptimal levels of excitability within unisensory cortices may be better suited for enhanced crossmodal interactions. Overall, our findings reveal early auditory-visual interactions due to the enhancement of visual cortical excitability by auditory stimuli. These interactions may reflect an underlying anatomical connectivity between unisensory cortices.
Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi B.
Enhancing navigation skills through audio gaming Journal Article
In: pp. 3991-3996, 2010.
@article{167001,
title = {Enhancing navigation skills through audio gaming},
author = {Jaime Sánchez and Mauricio Sáenz and Alvaro Pascual-Leone and Lotfi B. Merabet},
url = {http://dl.acm.org/citation.cfm?doid=1753846.1754091},
year = {2010},
date = {2010-01-01},
pages = {3991-3996},
abstract = {We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks.
Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi B.
Navigation for the blind through audio-based virtual environments Journal Article
In: IUI, pp. 3409-3414, 2010.
@article{166996,
title = {Navigation for the blind through audio-based virtual environments},
author = {Jaime Sánchez and Mauricio Sáenz and Alvaro Pascual-Leone and Lotfi B. Merabet},
url = {http://dl.acm.org/citation.cfm?doid=1753846.1753993},
year = {2010},
date = {2010-01-01},
journal = {IUI},
pages = {3409-3414},
abstract = {We present the design, development and an initial study changes and adaptations related to navigation that take place in the brain, by incorporating an Audio-Based Environments Simulator (AbES) within a neuroimaging environment. This virtual environment enables a blind user to navigate through a virtual representation of a real space in order to train his/her orientation and mobility skills. Our initial results suggest that this kind of virtual environment could be highly efficient as a testing, training and rehabilitation platform for learning and navigation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present the design, development and an initial study changes and adaptations related to navigation that take place in the brain, by incorporating an Audio-Based Environments Simulator (AbES) within a neuroimaging environment. This virtual environment enables a blind user to navigate through a virtual representation of a real space in order to train his/her orientation and mobility skills. Our initial results suggest that this kind of virtual environment could be highly efficient as a testing, training and rehabilitation platform for learning and navigation.
Merabet, Lotfi B.; Pascual-Leone, Alvaro
Neural reorganization following sensory loss: the opportunity of change Journal Article
In: Nat Rev Neurosci, vol. 11, no. 1, pp. 44-52, 2010, ISSN: 1471-0048.
@article{55166,
title = {Neural reorganization following sensory loss: the opportunity of change},
author = {Lotfi B. Merabet and Alvaro Pascual-Leone},
doi = {10.1038/nrn2758},
issn = {1471-0048},
year = {2010},
date = {2010-01-01},
journal = {Nat Rev Neurosci},
volume = {11},
number = {1},
pages = {44-52},
abstract = {There is growing evidence that sensory deprivation is associated with crossmodal neuroplastic changes in the brain. After visual or auditory deprivation, brain areas that are normally associated with the lost sense are recruited by spared sensory modalities. These changes underlie adaptive and compensatory behaviours in blind and deaf individuals. Although there are differences between these populations owing to the nature of the deprived sensory modality, there seem to be common principles regarding how the brain copes with sensory loss and the factors that influence neuroplastic changes. Here, we discuss crossmodal neuroplasticity with regards to behavioural adaptation after sensory deprivation and highlight the possibility of maladaptive consequences within the context of rehabilitation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
There is growing evidence that sensory deprivation is associated with crossmodal neuroplastic changes in the brain. After visual or auditory deprivation, brain areas that are normally associated with the lost sense are recruited by spared sensory modalities. These changes underlie adaptive and compensatory behaviours in blind and deaf individuals. Although there are differences between these populations owing to the nature of the deprived sensory modality, there seem to be common principles regarding how the brain copes with sensory loss and the factors that influence neuroplastic changes. Here, we discuss crossmodal neuroplasticity with regards to behavioural adaptation after sensory deprivation and highlight the possibility of maladaptive consequences within the context of rehabilitation.
Merabet, Lotfi B; Pascual-Leone, Alvaro
Neural reorganization following sensory loss: the opportunity of change Journal Article
In: Nat Rev Neurosci, vol. 11, no. 1, pp. 44–52, 2010, ISSN: 1471-0048.
@article{pmid19935836,
title = {Neural reorganization following sensory loss: the opportunity of change},
author = {Lotfi B Merabet and Alvaro Pascual-Leone},
doi = {10.1038/nrn2758},
issn = {1471-0048},
year = {2010},
date = {2010-01-01},
journal = {Nat Rev Neurosci},
volume = {11},
number = {1},
pages = {44--52},
abstract = {There is growing evidence that sensory deprivation is associated with crossmodal neuroplastic changes in the brain. After visual or auditory deprivation, brain areas that are normally associated with the lost sense are recruited by spared sensory modalities. These changes underlie adaptive and compensatory behaviours in blind and deaf individuals. Although there are differences between these populations owing to the nature of the deprived sensory modality, there seem to be common principles regarding how the brain copes with sensory loss and the factors that influence neuroplastic changes. Here, we discuss crossmodal neuroplasticity with regards to behavioural adaptation after sensory deprivation and highlight the possibility of maladaptive consequences within the context of rehabilitation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
There is growing evidence that sensory deprivation is associated with crossmodal neuroplastic changes in the brain. After visual or auditory deprivation, brain areas that are normally associated with the lost sense are recruited by spared sensory modalities. These changes underlie adaptive and compensatory behaviours in blind and deaf individuals. Although there are differences between these populations owing to the nature of the deprived sensory modality, there seem to be common principles regarding how the brain copes with sensory loss and the factors that influence neuroplastic changes. Here, we discuss crossmodal neuroplasticity with regards to behavioural adaptation after sensory deprivation and highlight the possibility of maladaptive consequences within the context of rehabilitation.
Obretenova, Souzana; Halko, Mark A; Plow, Ela B; Pascual-Leone, Alvaro; Merabet, Lotfi B
Neuroplasticity associated with tactile language communication in a deaf-blind subject Journal Article
In: Front Hum Neurosci, vol. 3, pp. 60, 2010, ISSN: 1662-5161.
@article{pmid20130756,
title = {Neuroplasticity associated with tactile language communication in a deaf-blind subject},
author = {Souzana Obretenova and Mark A Halko and Ela B Plow and Alvaro Pascual-Leone and Lotfi B Merabet},
doi = {10.3389/neuro.09.060.2009},
issn = {1662-5161},
year = {2010},
date = {2010-01-01},
journal = {Front Hum Neurosci},
volume = {3},
pages = {60},
abstract = {A long-standing debate in cognitive neuroscience pertains to the innate nature of language development and the underlying factors that determine this faculty. We explored the neural correlates associated with language processing in a unique individual who is early blind, congenitally deaf, and possesses a high level of language function. Using functional magnetic resonance imaging (fMRI), we compared the neural networks associated with the tactile reading of words presented in Braille, Print on Palm (POP), and a haptic form of American Sign Language (haptic ASL or hASL). With all three modes of tactile communication, indentifying words was associated with robust activation within occipital cortical regions as well as posterior superior temporal and inferior frontal language areas (lateralized within the left hemisphere). In a normally sighted and hearing interpreter, identifying words through hASL was associated with left-lateralized activation of inferior frontal language areas however robust occipital cortex activation was not observed. Diffusion tensor imaging -based tractography revealed differences consistent with enhanced occipital-temporal connectivity in the deaf-blind subject. Our results demonstrate that in the case of early onset of both visual and auditory deprivation, tactile-based communication is associated with an extensive cortical network implicating occipital as well as posterior superior temporal and frontal associated language areas. The cortical areas activated in this deaf-blind subject are consistent with characteristic cortical regions previously implicated with language. Finally, the resilience of language function within the context of early and combined visual and auditory deprivation may be related to enhanced connectivity between relevant cortical areas.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A long-standing debate in cognitive neuroscience pertains to the innate nature of language development and the underlying factors that determine this faculty. We explored the neural correlates associated with language processing in a unique individual who is early blind, congenitally deaf, and possesses a high level of language function. Using functional magnetic resonance imaging (fMRI), we compared the neural networks associated with the tactile reading of words presented in Braille, Print on Palm (POP), and a haptic form of American Sign Language (haptic ASL or hASL). With all three modes of tactile communication, indentifying words was associated with robust activation within occipital cortical regions as well as posterior superior temporal and inferior frontal language areas (lateralized within the left hemisphere). In a normally sighted and hearing interpreter, identifying words through hASL was associated with left-lateralized activation of inferior frontal language areas however robust occipital cortex activation was not observed. Diffusion tensor imaging -based tractography revealed differences consistent with enhanced occipital-temporal connectivity in the deaf-blind subject. Our results demonstrate that in the case of early onset of both visual and auditory deprivation, tactile-based communication is associated with an extensive cortical network implicating occipital as well as posterior superior temporal and frontal associated language areas. The cortical areas activated in this deaf-blind subject are consistent with characteristic cortical regions previously implicated with language. Finally, the resilience of language function within the context of early and combined visual and auditory deprivation may be related to enhanced connectivity between relevant cortical areas.
2009
Plow, Ela B; Maguire, Sara; Obretenova, Souzana; Pascual-Leone, Alvaro; Merabet, Lotfi B.
Approaches to rehabilitation for visual field defects following brain lesions Journal Article
In: Expert Rev Med Devices, vol. 6, no. 3, pp. 291-305, 2009, ISSN: 1745-2422.
@article{55161,
title = {Approaches to rehabilitation for visual field defects following brain lesions},
author = {Ela B Plow and Sara Maguire and Souzana Obretenova and Alvaro Pascual-Leone and Lotfi B. Merabet},
doi = {10.1586/erd.09.8},
issn = {1745-2422},
year = {2009},
date = {2009-05-01},
journal = {Expert Rev Med Devices},
volume = {6},
number = {3},
pages = {291-305},
abstract = {Visual field defects often result from stroke and brain injury. The resulting visual impairment can be debilitating for patients, impeding daily activities such as reading and mobility. Historically, it was believed that there was little opportunity for restoration of function following visual system damage. However, the development of various visual rehabilitative strategies suggests that visual field defects are partially repairable and a certain degree of function can be improved. While this provides hope for patients, many of these strategies have been met with skepticism within the clinical and scientific communities. Further development of these strategies through carefully designed studies could validate their efficacy and reveal underlying mechanisms. Novel techniques, aimed at enhancing the effect of these rehabilitative strategies, are also discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Visual field defects often result from stroke and brain injury. The resulting visual impairment can be debilitating for patients, impeding daily activities such as reading and mobility. Historically, it was believed that there was little opportunity for restoration of function following visual system damage. However, the development of various visual rehabilitative strategies suggests that visual field defects are partially repairable and a certain degree of function can be improved. While this provides hope for patients, many of these strategies have been met with skepticism within the clinical and scientific communities. Further development of these strategies through carefully designed studies could validate their efficacy and reveal underlying mechanisms. Novel techniques, aimed at enhancing the effect of these rehabilitative strategies, are also discussed.