@article{pmid37990438,

title = {Academic skills in children with cerebral palsy and specific learning disorders},

author = {Serena Micheletti and Jessica Galli and Marika Vezzoli and Vera Scaglioni and Stefania Agostini and Stefano Calza and Lotfi B Merabet and Elisa Fazzi},

doi = {10.1111/dmcn.15808},

issn = {1469-8749},

year  = {2023},

date = {2023-11-01},

journal = {Dev Med Child Neurol},

abstract = {AIM: To investigate the prevalence and clinical manifestations of reading, writing, and mathematics disorders in children with cerebral palsy (CP). We explored how the clinical profile of these children differed from those with specific learning disorders (SLDs), taking into account several factors, particularly IQ scores, neuropsychological aspects, and the presence of a visual impairment.nnMETHOD: A prospective cross-sectional study was conducted in 42 children with CP (mean age 9 years 8 months; SD = 2 years 2 months) and 60 children with SLDs (mean age 10 years; SD = 1 year 7 months). Clinical characteristics, neuromotor and cognitive profiles, neuropsychological aspects (speech performance, academic skills, visual attention, phonological awareness, working memory), and signs of visual impairment (visual acuity, contrast sensitivity, visual field, oculomotor functions) were assessed. A machine learning approach consisting of a random forest algorithm, where the outcome was the diagnosis and the covariates were the clinical variables collected in the sample, was used for the analyses.nnRESULTS: About 59% of the children with CP had reading, writing, or mathematics disorders. Children with CP with learning disorders had a low performance IQ, normal phonological awareness, and working memory difficulties, whereas children with SLDs had normal performance IQ, impaired phonological awareness, and mild working memory difficulties. There were no differences in verbal IQ between the two groups.nnINTERPRETATION: Learning disorders are frequently associated with CP, with different clinical characteristics, compared with SLDs. Assessment of academic skills is mandatory in these children, even if the IQ is normal. At school age, specific interventions to promote academic skills in children with CP could be a major rehabilitative goal.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37012700,

title = {Motion and form coherence processing in individuals with cerebral visual impairment},

author = {Lotfi B Merabet and Claire E Manley and Zahide Pamir and Corinna M Bauer and Jan Skerswetat and Peter J Bex},

doi = {10.1111/dmcn.15591},

issn = {1469-8749},

year  = {2023},

date = {2023-10-01},

journal = {Dev Med Child Neurol},

volume = {65},

number = {10},

pages = {1379--1386},

abstract = {AIM: Using a visual psychophysical paradigm, we sought to assess motion and form coherence thresholds as indices of dorsal and ventral visual stream processing respectively, in individuals with cerebral visual impairment (CVI). We also explored potential associations between psychophysical assessments and brain lesion severity in CVI.nnMETHOD: Twenty individuals previously diagnosed with CVI (mean age = 17 years 11 months [SD 5 years 10 months]; mean Verbal IQ = 86.42 [SD 35.85]) and 30 individuals with neurotypical development (mean age = 20 years 1 month [SD 3 years 8 months]; mean Verbal IQ = 110.05 [SD 19.34]) participated in the study. In this two-group comparison, cross-sectional study design, global motion, and form pattern coherence thresholds were assessed using a computerized, generalizable, self-administrable, and response-adaptive psychophysical paradigm called FInD (Foraging Interactive D-prime).nnRESULTS: Consistent with dorsal stream dysfunction, mean global motion (but not form) coherence thresholds were significantly higher in individuals with CVI compared to controls. No statistically significant association was found between coherence thresholds and lesion severity.nnINTERPRETATION: These results suggest that the objective assessment of motion and form coherence threshold sensitivities using this psychophysical paradigm may be useful in helping to characterize perceptual deficits and the complex clinical profile of CVI.nnWHAT THIS PAPER ADDS: In participants with cerebral visual impairment (CVI), motion (but not form) coherence thresholds were significantly higher compared to controls. These psychophysical results support the notion of dorsal stream dysfunction in CVI.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37188548,

title = {Object identification in cerebral visual impairment characterized by gaze behavior and image saliency analysis},

author = {Claire E Manley and Kerri Walter and Serena Micheletti and Matthew Tietjen and Emily Cantillon and Elisa M Fazzi and Peter J Bex and Lotfi B Merabet},

doi = {10.1016/j.braindev.2023.05.001},

issn = {1872-7131},

year  = {2023},

date = {2023-09-01},

journal = {Brain Dev},

volume = {45},

number = {8},

pages = {432--444},

abstract = {Individuals with cerebral visual impairment (CVI) have difficulties identifying common objects, especially when presented as cartoons or abstract images. In this study, participants were shown a series of images of ten common objects, each from five possible categories ranging from abstract black & white line drawings to color photographs. Fifty individuals with CVI and 50 neurotypical controls verbally identified each object and success rates and reaction times were collected. Visual gaze behavior was recorded using an eye tracker to quantify the extent of visual search area explored and number of fixations. A receiver operating characteristic (ROC) analysis was also carried out to compare the degree of alignment between the distribution of individual eye gaze patterns and image saliency features computed by the graph-based visual saliency (GBVS) model. Compared to controls, CVI participants showed significantly lower success rates and longer reaction times when identifying objects. In the CVI group, success rate improved moving from abstract black & white images to color photographs, suggesting that object form (as defined by outlines and contours) and color are important cues for correct identification. Eye tracking data revealed that the CVI group showed significantly greater visual search areas and number of fixations per image, and the distribution of eye gaze patterns in the CVI group was less aligned with the high saliency features of the image compared to controls. These results have important implications in helping to understand the complex profile of visual perceptual difficulties associated with CVI.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36217264,

title = {Visual intervention in early onset visual impairment: A review},

author = {Serena Micheletti and Lotfi B Merabet and Jessica Galli and Elisa Fazzi},

doi = {10.1111/ejn.15841},

issn = {1460-9568},

year  = {2023},

date = {2023-06-01},

journal = {Eur J Neurosci},

volume = {57},

number = {12},

pages = {1998--2016},

abstract = {Vision is a primary and motivating sense. Early visual experience derived from the external world is known to have an important impact on the development of central visual pathways, and not surprisingly, visual impairment constitutes a risk factor for overall development. In light of the role of vision in early brain development, infants and young children with visual impairment should be thus entitled to early and effective visual intervention programmes. In this review, we discuss early visual interventions in infants and young children with visual impairment, focusing on their contents and outcomes. We defined a PICO format to critically review different models with a particular focus on parent-mediated and therapist-mediated approaches. We consider protocols that involved direct manipulation or improvement of the infants' visual inputs or were based on behavioural strategies and communication towards infants with visual impairment. We also provide an overview of the effectiveness of these protocols. A total of nine intervention protocols were selected for the purposes of this review. Substantial agreement regarding the importance of promoting the enrichment of infant environments, and more specifically in the context of active play that engages the whole family, has been reported in most of the studies. However, there is no clear agreement on methodological aspects, including clinical population characteristics, outcome measures, length of treatment and follow-up programmes. Further high-quality, carefully designed and adequately reported studies are needed in order to improve the clinical efficacy of these approaches to treating infants with visual impairment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36968165,

title = {Development and 5-year Evaluation of Diagnosis-Specific Protocols for Visual Neuro-Rehabilitation in a Multicenter Inpatient Rehabilitation Network},

author = {Kevin E Houston and Matthew Keilty and Caroline Collins and Ritika Trehan and Talia Mouldovan and Kim Stuckart and Nancy Engelhardt and Melanie Nadeau and Craig A Rovito and Lotfi B Merabet},

doi = {10.1016/j.arrct.2022.100246},

issn = {2590-1095},

year  = {2023},

date = {2023-03-01},

journal = {Arch Rehabil Res Clin Transl},

volume = {5},

number = {1},

pages = {100246},

abstract = {OBJECTIVE: To provide a retrospective evaluation of a new eye and vision rehabilitation care pathway in a U.S. multi-site inpatient rehabilitation network involving the occupational therapy (OT) staff and a consulting doctor of optometry (OD) specializing in vision rehabilitation.nnDESIGN: Retrospective study.nnSETTING: Two Inpatient Rehabilitation Facilities (IRFs) and 1 Long Term Acute Care Hospital (LTACH).nnPARTICIPANTS: There were 2083 records reviewed (44% women, avg. age 59 years). The most common diagnoses were hemispatial neglect (19.2%), homonymous field defects (18.5%), and oculomotor cranial nerve palsies (16.7%) (N=2083).nnINTERVENTIONS: Clinical care was reviewed where diagnosis-specific protocols were developed and training was provided to OTs in order to reinforce OD-prescribed interventions during daily treatment sessions, including (1) third, fourth, and sixth ocular cranial nerve palsies (OCNPs) with prisms fitted for full time, postural adaptation training, and oculomotor re-education using pursuits, saccades, head-rotations, and binocular vision exercises including alternate cover and vergence; (2) homonymous hemianopia with training awareness of field loss, eccentric viewing, and fitting of Peli lens for optical field expansion; and (3) prism adaptation therapy (PAT) for left hemispatial neglect.nnMAIN OUTCOME MEASURES: Frequency of diagnoses.nnHYPOTHESIS: Diagnoses with developed protocols were most common. Secondarily, feasibility and efficacy by anonymous OT survey.nnRESULTS: 2083 vision consults were performed over 5 years. The most common diagnoses were hemispatial neglect (n=399, 19.2%), homonymous field defects (n=386, 18.5%), and OCNPs (n=347, 16.7%). None of the OTs reported the protocols were infeasible and 63% (IQR 38%-69%) reported their patients benefited from the interventions. The survey suggested prism for OCNPs helped in 42%, and Peli lens and PAT both helped in 38%.nnCONCLUSIONS: Data support the feasibility of this inpatient eye and vision rehabilitation care pathway which may be used as a foundation for creating or refining similar programs elsewhere. Uniform administration of IRF-based visual neuro-rehabilitation care could provide a substrate for future clinical trials to evaluate efficacy.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36344336,

title = {Neurovisual profile in children affected by Angelman syndrome},

author = {Jessica Galli and Erika Loi and Caterina Strobio and Serena Micheletti and Paola Martelli and Lotfi B Merabet and Nadia Pasini and Francesco Semeraro and Elisa Fazzi and },

doi = {10.1016/j.braindev.2022.10.003},

issn = {1872-7131},

year  = {2023},

date = {2023-02-01},

journal = {Brain Dev},

volume = {45},

number = {2},

pages = {117--125},

abstract = {BACKGROUND: Angelman syndrome (AS) is a rare neurogenetic disorder caused by altered expression of the maternal copy of the UBE3A gene. Together with motor, cognitive, and speech impairment, ophthalmological findings including strabismus, and ocular fundus hypopigmentation characterize the clinical phenotype. The aim of this study was to detail the neurovisual profile of children affected by AS and to explore any possible genotype-phenotype correlations.nnMETHODS: Thirty-seven children (23 females, mean age 102.8 ± 54.4 months, age range 22 to 251 months) with molecular confirmed diagnosis of AS were enrolled in the study. All underwent a comprehensive video-recorded neurovisual evaluation including the assessment of ophthalmological aspects, oculomotor functions, and basic visual abilities.nnRESULTS: All children had visual impairments mainly characterized by refractive errors, ocular fundus changes, strabismus, discontinuous/jerky smooth pursuit and altered saccadic movements, and/or reduced visual acuity. Comparing the neurovisual profiles between the deletion and non-deletion genetic subgroups, we found a significant statistical correlation between genotype and ocular fundus hypopigmentation (p = 0.03), discontinuous smooth pursuit (p < 0.05), and contrast sensitivity abnormalities (p < 0.01) being more frequent in the deletion subgroup.nnCONCLUSIONS: Subjects affected by AS present a wide spectrum of neurovisual impairments that lead to a clinical profile consistent with cerebral visual impairment (CVI). Moreover, subjects with a chromosome deletion show a more severe visual phenotype with respect to ocular fundus changes, smooth pursuit movements, and contrast sensitivity. Early detection of these impaired visual functions may help promote the introduction of neurovisual habilitative programs which can improve children's visual, neuromotor, and cognitive outcomes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37693815,

title = {Altered neural oscillations underlying visuospatial processing in cerebral visual impairment},

author = {Alessandra Federici and Christopher R Bennett and Corinna M Bauer and Claire E Manley and Emiliano Ricciardi and Davide Bottari and Lotfi B Merabet},

doi = {10.1093/braincomms/fcad232},

issn = {2632-1297},

year  = {2023},

date = {2023-01-01},

journal = {Brain Commun},

volume = {5},

number = {5},

pages = {fcad232},

abstract = {Visuospatial processing deficits are commonly observed in individuals with cerebral visual impairment, even in cases where visual acuity and visual field functions are intact. Cerebral visual impairment is a brain-based visual disorder associated with the maldevelopment of central visual pathways and structures. However, the neurophysiological basis underlying higher-order perceptual impairments in this condition has not been clearly identified, which in turn poses limits on developing rehabilitative interventions. Using combined eye tracking and EEG recordings, we assessed the profile and performance of visual search on a naturalistic virtual reality-based task. Participants with cerebral visual impairment and controls with neurotypical development were instructed to search, locate and fixate on a specific target placed among surrounding distractors at two levels of task difficulty. We analysed evoked (phase-locked) and induced (non-phase-locked) components of broadband (4-55 Hz) neural oscillations to uncover the neurophysiological basis of visuospatial processing. We found that visual search performance in cerebral visual impairment was impaired compared to controls (as indexed by outcomes of success rate, reaction time and gaze error). Analysis of neural oscillations revealed markedly reduced early-onset evoked theta [4-6 Hz] activity (within 0.5 s) regardless of task difficulty. Moreover, while induced alpha activity increased with task difficulty in controls, this modulation was absent in the cerebral visual impairment group identifying a potential neural correlate related to deficits with visual search and distractor suppression. Finally, cerebral visual impairment participants also showed a sustained induced gamma response [30-45 Hz]. We conclude that impaired visual search performance in cerebral visual impairment is associated with substantial alterations across a wide range of neural oscillation frequencies. This includes both evoked and induced components suggesting the involvement of feedforward and feedback processing as well as local and distributed levels of neural processing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36334401,

title = {Assessing visuospatial processing in cerebral visual impairment using a novel and naturalistic static visual search task},

author = {Xin Zhang and Claire E Manley and Serena Micheletti and Isidora Tesic and Christopher R Bennett and Elisa M Fazzi and Lotfi B Merabet},

doi = {10.1016/j.ridd.2022.104364},

issn = {1873-3379},

year  = {2022},

date = {2022-12-01},

journal = {Res Dev Disabil},

volume = {131},

pages = {104364},

abstract = {BACKGROUND: Cerebral visual impairment (CVI) is a brain based visual disorder associated with the maldevelopment of central visual pathways. Individuals with CVI often report difficulties finding a target of interest in cluttered and crowded visual scenes. However, it remains unknown how manipulating task demands and other environmental factors influence visual search performance in this population.nnAIM: We developed a novel and naturalistic virtual reality (VR) based static visual search task combined with eye tracking called the "virtual toy box" to objectively assess visual search performance in CVI.nnMETHODS AND PROCEDURES: A total of 38 individuals with CVI (mean age 13.18 years ± 3.58 SD) and 53 controls with neurotypical development (mean age 15.25 years ± 5.72 SD) participated in the study. In a first experiment, study subjects were instructed to search for a preselected toy presented among a varying number of surrounding distractor toys (set size ranging from 1 to 36 items). In a second experiment, we assessed the effects of manipulating item spacing and the size of the visual area explored (field of view; FOV).nnOUTCOMES AND RESULTS: Behavioral outcomes collected were success rate, reaction time, gaze error, visual search area, and off-screen percent (an index of task compliance). Compared to age-matched controls, participants with CVI showed an overall impairment with respect to all the visual search outcomes of interest. Specifically, individuals with CVI were less likely and took longer to find the target, and search patterns were less accurate and precise compared to controls. Visual search response profiles were also comparatively less efficient and were associated with a slower initial pre-search (visual orienting) response as indexed by higher slope and intercept values derived from the analysis of reaction time × set size functions. Search performance was also more negatively affected in CVI at the smallest as well as largest spacing conditions tested, while increasing FOV was associated with greater decreased gaze accuracy and precision CONCLUSIONS AND IMPLICATIONS: These results are consistent with a general profile of impaired visual search abilities in CVI as well as worsening performance with increased visual task demands and an overall sensitivity to visual clutter and crowding. The observed profile of impaired visual search performance may be associated with dysfunctions related to how visual selective attention is deployed in individuals with CVI.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35892617,

title = {Assessing Higher-Order Visual Processing in Cerebral Visual Impairment Using Naturalistic Virtual-Reality-Based Visual Search Tasks},

author = {Claire E Manley and Christopher R Bennett and Lotfi B Merabet},

doi = {10.3390/children9081114},

issn = {2227-9067},

year  = {2022},

date = {2022-07-01},

journal = {Children (Basel)},

volume = {9},

number = {8},

abstract = {Cerebral visual impairment (CVI) is a brain-based disorder associated with the maldevelopment of central visual pathways. Individuals with CVI often report difficulties with daily visual search tasks such as finding a favorite toy or familiar person in cluttered and crowded scenes. We developed two novel virtual reality (VR)-based visual search tasks combined with eye tracking to objectively assess higher order processing abilities in CVI. The first (virtual toybox) simulates a static object search, while the second (virtual hallway) represents a dynamic human search task. Participants were instructed to search for a preselected target while task demand was manipulated with respect to the presence of surrounding distractors. We found that CVI participants (when compared to age-matched controls) showed an overall impairment with visual search on both tasks and with respect to all gaze metrics. Furthermore, CVI participants showed a trend of worsening performance with increasing task demand. Finally, search performance was also impaired in CVI participants with normal/near normal visual acuity, suggesting that reduced stimulus visibility alone does not account for these observations. This novel approach may have important clinical utility in helping to assess environmental factors related to functional visual processing difficulties observed in CVI.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34813110,

title = {Early visual training and environmental adaptation for infants with visual impairment},

author = {Elisa Fazzi and Serena Micheletti and Stefano Calza and Lotfi Merabet and Andrea Rossi and Jessica Galli and },

doi = {10.1111/dmcn.14865},

issn = {1469-8749},

year  = {2021},

date = {2021-10-01},

journal = {Dev Med Child Neurol},

volume = {63},

number = {10},

pages = {1180--1193},

abstract = {AIM: To evaluate the effectiveness of early visual training and environmental adaptation on visual function and neurological development in infants with visual impairment.nnMETHOD: This was a pilot intervention clinical trial study. Thirty infants (mean age 5.9mo, SD 2.1mo, range 4-11mo; 16 males, 14 females) with peripheral visual impairment (PVI, n=15) or cerebral visual impairment (CVI, n=15) participated in a 6-month visual intervention programme. Thirty matched infants (mean age 6mo, SD 1.4mo, range 4-9mo; 18 males, 12 females) served as a comparison group. Primary outcome measures were visual acuity, contrast sensitivity, and qualitative ocular motor functions. Secondary outcomes were scores on the Griffiths Mental Developmental Scales (GMDS).nnRESULTS: The treatment group showed a significant improvement in all the primary outcomes (p<0.01). The comparison group improved only in visual acuity and contrast sensitivity (p<0.01). The treatment group showed greater improvement than the comparison group in visual fixation (p=0.033) and smooth pursuit (p<0.01). The CVI subgroup showed greater improvement in visual acuity than the PVI subgroup (p<0.01). GMDS subscales of hand-eye coordination (p=0.01) and performance (p<0.01) increased in the treatment group, while the total score of the comparison group decreased, driven by language (p=0.039) and hand-eye coordination (p=0.025) subscales.nnINTERPRETATION: Results suggest that, in infants with visual impairment, visual function and certain developmental outcomes improve in response to early visual training and environmental adaptation, in an interactive context. What this paper adds Early visual training and environmental adaptation are associated with enhanced visual acuity and smooth pursuit. Early visual training and environmental adaptation are associated with an improvement of neurological developmental outcome. Performance, hand-eye coordination, and language scores in Griffiths Mental Developmental Scales increase after visual training. After training, visual acuity improves more in infants with cerebral rather than anterior visual impairment. Type and complexity of visual impairment contribute to determine infants' response to training.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bennett2021,

title = {Assessing visual search performance using a novel dynamic naturalistic scene},

author = {Christopher R. Bennett and Peter J. Bex and Lotfi B. Merabet},

doi = {10.1167/jov.21.1.5},

issn = {1534-7362},

year  = {2021},

date = {2021-01-04},

journal = {Journal of Vision},

volume = {21},

number = {1},

publisher = {Association for Research in Vision and Ophthalmology (ARVO)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34628303,

title = {Neural correlates associated with impaired global motion perception in cerebral visual impairment (CVI)},

author = {Zahide Pamir and Corinna M Bauer and Emma S Bailin and Peter J Bex and David C Somers and Lotfi B Merabet},

doi = {10.1016/j.nicl.2021.102821},

issn = {2213-1582},

year  = {2021},

date = {2021-01-01},

journal = {Neuroimage Clin},

volume = {32},

pages = {102821},

abstract = {Cerebral visual impairment (CVI) is associated with a wide range of visual perceptual deficits including global motion processing. However, the underlying neurophysiological basis for these impairments remain poorly understood. We investigated global motion processing abilities in individuals with CVI compared to neurotypical controls using a combined behavioral and multi-modal neuroimaging approach. We found that CVI participants had a significantly higher mean motion coherence threshold (determined using a random dot kinematogram pattern simulating optic flow motion) compared to controls. Using functional magnetic resonance imaging (fMRI), we investigated activation response profiles in functionally defined early (i.e. primary visual cortex; area V1) and higher order (i.e. middle temporal cortex; area hMT+) stages of motion processing. In area V1, responses to increasing motion coherence were similar in both groups. However, in the CVI group, activation in area hMT+ was significantly reduced compared to controls, and consistent with a surround facilitation (rather than suppression) response profile. White matter tract reconstruction obtained from high angular resolution diffusion imaging (HARDI) revealed evidence of increased mean, axial, and radial diffusivities within cortico-cortical (i.e. V1-hMT+), but not thalamo-hMT+ connections. Overall, our results suggest that global motion processing deficits in CVI may be associated with impaired signal integration and segregation mechanisms, as well as white matter integrity at the level of area hMT+.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rinaldi2020,

title = {The Effect of Blindness on Spatial Asymmetries},

author = {Luca Rinaldi and Andrea Ciricugno and Lotfi B. Merabet and Tomaso Vecchi and Zaira Cattaneo},

doi = {10.3390/brainsci10100662},

issn = {2076-3425},

year  = {2020},

date = {2020-10-00},

journal = {Brain Sciences},

volume = {10},

number = {10},

publisher = {MDPI AG},

abstract = {The human cerebral cortex is asymmetrically organized with hemispheric lateralization pervading nearly all neural systems of the brain. Whether the lack of normal visual development affects hemispheric specialization subserving the deployment of visuospatial attention asymmetries is controversial. In principle, indeed, the lack of early visual experience may affect the lateralization of spatial functions, and the blind may rely on a different sensory input compared to the sighted. In this review article, we thus present a current state-of-the-art synthesis of empirical evidence concerning the effects of visual deprivation on the lateralization of various spatial processes (i.e., including line bisection, mirror symmetry, and localization tasks). Overall, the evidence reviewed indicates that spatial processes are supported by a right hemispheric network in the blind, hence, analogously to the sighted. Such a right-hemisphere dominance, however, seems more accentuated in the blind as compared to the sighted as indexed by the greater leftward bias shown in different spatial tasks. This is possibly the result of the more pronounced involvement of the right parietal cortex during spatial tasks in blind individuals compared to the sighted, as well as of the additional recruitment of the right occipital cortex, which would reflect the cross-modal plastic phenomena that largely characterize the blind brain.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32752249,

title = {Autistic-Like Features in Visually Impaired Children: A Review of Literature and Directions for Future Research},

author = {Anna Molinaro and Serena Micheletti and Andrea Rossi and Filippo Gitti and Jessica Galli and Lotfi B Merabet and Elisa Maria Fazzi},

doi = {10.3390/brainsci10080507},

issn = {2076-3425},

year  = {2020},

date = {2020-08-01},

journal = {Brain Sci},

volume = {10},

number = {8},

abstract = {There remains great interest in understanding the relationship between visual impairment (VI) and autism spectrum disorder (ASD) due to the extraordinarily high prevalence of ASD in blind and visually impaired children. The broad variability across individuals and assessment methodologies have made it difficult to understand whether autistic-like symptoms shown by some children with VI might reflect the influence of the visual deficit, or represent a primary neurodevelopmental condition that occurs independently of the VI itself. In the absence of a valid methodology adapted for the visually impaired population, diagnosis of ASD in children with VI is often based on non-objective clinical impression, with inconclusive prevalence data. In this review, we discuss the current state of knowledge and suggest directions for future research.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ciricugno2020,

title = {The Role of Binocular Vision in Driving Pseudoneglect in Visual and Haptic Bisection: Evidence From Strabismic and Monocular Blind Individuals},

author = {Andrea Ciricugno and Luca Rinaldi and Tomaso Vecchi and Lotfi B. Merabet and Zaira Cattaneo},

doi = {10.1163/22134808-20191347},

issn = {2213-4808},

year  = {2020},

date = {2020-03-17},

journal = {Multisens. Res.},

volume = {33},

number = {4-5},

pages = {549--567},

publisher = {Brill},

abstract = {Abstract

Prior studies have shown that strabismic amblyopes do not exhibit pseudoneglect in visual line bisection, suggesting that the right-hemisphere dominance in the control of spatial attention may depend on a normally developing binocular vision. In this study, we aimed to investigate whether an abnormal binocular childhood experience also affects spatial attention in the haptic modality, thus reflecting a supramodal effect. To this aim, we compared the performance of normally sighted, strabismic and early monocular blind participants in a visual and a haptic line bisection task. In visual line bisection, strabismic individuals tended to err to the right of the veridical midpoint, in contrast with normally sighted participants who showed pseudoneglect. Monocular blind participants exhibited high variability in their visual performance, with a tendency to bisect toward the direction of the functioning eye. In turn, in haptic bisection, all participants consistently erred towards the left of the veridical midpoint. Taken together, our findings support the view that pseudoneglect in the visual and haptic modality relies on different functional and neural mechanisms.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{BENNETT2020171,

title = {Neuroplasticity in cerebral visual impairment (CVI): Assessing functional vision and the neurophysiological correlates of dorsal stream dysfunction},

author = {Christopher R. Bennett and Corinna M. Bauer and Emma S. Bailin and Lotfi B. Merabet},

doi = {https://doi.org/10.1016/j.neubiorev.2019.10.011},

issn = {0149-7634},

year  = {2020},

date = {2020-01-01},

journal = {Neuroscience & Biobehavioral Reviews},

volume = {108},

pages = {171 - 181},

abstract = {Cerebral visual impairment (CVI) results from perinatal injury to visual processing structures and pathways and is the most common individual cause of pediatric visual impairment and blindness in developed countries. While there is mounting evidence demonstrating extensive neuroplastic reorganization in early onset, profound ocular blindness, how the brain reorganizes in the setting of congenital damage to cerebral (i.e. retro-geniculate) visual pathways remains comparatively poorly understood. Individuals with CVI exhibit a wide range of visual deficits and, in particular, present with impairments of higher order visual spatial processing (referred to as “dorsal stream dysfunction”) as well as object recognition (associated with processing along the ventral stream). In this review, we discuss the need for ongoing work to develop novel, neuroscience-inspired approaches to investigate functional visual deficits in this population. We also outline the role played by advanced structural and functional neuroimaging in helping to elucidate the underlying neurophysiology of CVI, and highlight key differences with regard to patterns of neural reorganization previously described in ocular blindness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{BENNETT2020171b,

title = {Neuroplasticity in cerebral visual impairment (CVI): Assessing functional vision and the neurophysiological correlates of dorsal stream dysfunction},

author = {Christopher R. Bennett and Corinna M. Bauer and Emma S. Bailin and Lotfi B. Merabet},

doi = {https://doi.org/10.1016/j.neubiorev.2019.10.011},

issn = {0149-7634},

year  = {2020},

date = {2020-01-01},

journal = {Neuroscience & Biobehavioral Reviews},

volume = {108},

pages = {171 - 181},

abstract = {Cerebral visual impairment (CVI) results from perinatal injury to visual processing structures and pathways and is the most common individual cause of pediatric visual impairment and blindness in developed countries. While there is mounting evidence demonstrating extensive neuroplastic reorganization in early onset, profound ocular blindness, how the brain reorganizes in the setting of congenital damage to cerebral (i.e. retro-geniculate) visual pathways remains comparatively poorly understood. Individuals with CVI exhibit a wide range of visual deficits and, in particular, present with impairments of higher order visual spatial processing (referred to as “dorsal stream dysfunction”) as well as object recognition (associated with processing along the ventral stream). In this review, we discuss the need for ongoing work to develop novel, neuroscience-inspired approaches to investigate functional visual deficits in this population. We also outline the role played by advanced structural and functional neuroimaging in helping to elucidate the underlying neurophysiology of CVI, and highlight key differences with regard to patterns of neural reorganization previously described in ocular blindness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bennett2020,

title = {Neuroplasticity in cerebral visual impairment (CVI): Assessing functional vision and the neurophysiological correlates of dorsal stream dysfunction},

author = {Christopher R. Bennett and Corinna M. Bauer and Emma S. Bailin and Lotfi B. Merabet},

doi = {10.1016/j.neubiorev.2019.10.011},

issn = {0149-7634},

year  = {2020},

date = {2020-01-00},

journal = {Neuroscience & Biobehavioral Reviews},

volume = {108},

pages = {171--181},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bennett2019,

title = {The Assessment of Visual Function and Functional Vision},

author = {Christopher R. Bennett and Peter J. Bex and Corinna M. Bauer and Lotfi B. Merabet},

doi = {10.1016/j.spen.2019.05.006},

issn = {1071-9091},

year  = {2019},

date = {2019-10-00},

journal = {Seminars in Pediatric Neurology},

volume = {31},

pages = {30--40},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bauer2019,

title = {Perspectives on Cerebral Visual Impairment},

author = {Corinna M. Bauer and Lotfi B. Merabet},

doi = {10.1016/j.spen.2019.05.001},

issn = {1071-9091},

year  = {2019},

date = {2019-10-00},

journal = {Seminars in Pediatric Neurology},

volume = {31},

pages = {1--2},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{644622,

title = {Real-time Video Projection in an MRI for Characterization of Neural Correlates Associated with Mirror Therapy for Phantom Limb Pain},

author = {Faddi G. Saleh Velez and Camila B. Pinto and Emma S. Bailin and Marionna Münger and Andrew Ellison and Beatriz T. Costa and David Crandell and Nadia Bolognini and Lotfi B. Merabet and Felipe Fregni},

year  = {2019},

date = {2019-01-01},

journal = {Journal of visualized experiments},

number = {146},

abstract = {Mirror therapy (MT) has been proposed as an effective rehabilitative strategy to alleviate pain symptoms in amputees with phantom limb pain (PLP). However, establishing the neural correlates associated with MT therapy have been challenging given that it is difficult to administer the therapy effectively within a magnetic resonance imaging (MRI) scanner environment. To characterize the functional organization of cortical regions associated with this rehabilitative strategy, we have developed a combined behavioral and functional neuroimaging protocol that can be applied in participants with a leg amputation. This novel approach allows participants to undergo MT within the MRI scanner environment by viewing real-time video images captured by a camera. The images are viewed by the participant through a system of mirrors and a monitor that the participant views while lying on the scanner bed. In this manner, functional changes in cortical areas of interest (e.g., sensorimotor cortex) can be characterized in response to the direct application of MT.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30027677,

title = {White matter changes associated with cognitive visual dysfunctions in children with cerebral palsy: A diffusion tensor imaging study},

author = {Jessica Galli and Claudia Ambrosi and Serena Micheletti and Lotfi B Merabet and Chiara Pinardi and Roberto Gasparotti and Elisa Fazzi},

doi = {10.1002/jnr.24307},

issn = {1097-4547},

year  = {2018},

date = {2018-11-01},

journal = {J Neurosci Res},

volume = {96},

number = {11},

pages = {1766--1774},

abstract = {Children with cerebral palsy often present with cognitive-visual dysfunctions characterized by visuo-perceptual and/or visuo-spatial deficits associated with a malfunctioning of visual-associative areas. The neurofunctional model of this condition remains poorly understood due to the lack of a clear correlation between cognitive-visual deficit and morphological brain anomalies. The aim of our study was to quantify the pattern of white matter abnormalities within the whole brain in children with cerebral palsy, and to identify white matter tracts sub-serving cognitive-visual functions, in order to better understand the basis of cognitive-visual processing. Nine subjects (three males, mean age 8 years 9 months) with cerebral palsy underwent a visual and cognitive-visual evaluation. Conventional brain MRI and diffusion tensor imaging were performed. The fractional anisotropy maps were calculated for every child and compared with data from 13 (four males, mean age 10 years 7 months) healthy children. Children with cerebral palsy showed decreased fractional anisotropy (a marker of white matter integrity) in corticospinal tract bilaterally, left superior longitudinal fasciculus and bilateral hippocampus. Focusing on the superior longitudinal fasciculus, the mean fractional anisotropy values were significantly lower in children affected by cerebral palsy with cognitive-visual deficits than in those without cognitive-visual deficits. Our findings reveal an association between cognitive-visual profile and the superior longitudinal fasciculus integrity in children with cerebral palsy, supporting the hypothesis that visuo-associative deficits are related to changes in fibers connecting the occipital cortex with the parietal-frontal cortices. Decreased fractional anisotropy within the superior longitudinal fasciculus could be considered a biomarker for cognitive-visual dysfunctions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29746876,

title = {The spatial representation of number, time, and serial order following sensory deprivation: A systematic review},

author = {Luca Rinaldi and Lotfi B Merabet and Tomaso Vecchi and Zaira Cattaneo},

doi = {10.1016/j.neubiorev.2018.04.021},

issn = {1873-7528},

year  = {2018},

date = {2018-07-01},

journal = {Neurosci Biobehav Rev},

volume = {90},

pages = {371--380},

abstract = {The spatial representation of numerical and temporal information is thought to be rooted in our multisensory experiences. Accordingly, we may expect visual or auditory deprivation to affect the way we represent numerical magnitude and time spatially. Here, we systematically review recent findings on how blind and deaf individuals represent abstract concepts such as magnitude and time (e.g., past/future, serial order of events) in a spatial format. Interestingly, available evidence suggests that sensory deprivation does not prevent the spatial "re-mapping" of abstract information, but differences compared to normally sighted and hearing individuals may emerge depending on the specific dimension considered (i.e., numerical magnitude, time as past/future, serial order). Herein we discuss how the study of sensory deprived populations may shed light on the specific, and possibly distinct, mechanisms subserving the spatial representation of these concepts. Furthermore, we pinpoint unresolved issues that need to be addressed by future studies to grasp a full understanding of the spatial representation of abstract information associated with visual and auditory deprivation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29907530,

title = {Why Does the Cortex Reorganize after Sensory Loss?},

author = {Amy Kalia Singh and Flip Phillips and Lotfi B Merabet and Pawan Sinha},

doi = {10.1016/j.tics.2018.04.004},

issn = {1879-307X},

year  = {2018},

date = {2018-07-01},

journal = {Trends Cogn Sci},

volume = {22},

number = {7},

pages = {569--582},

abstract = {A growing body of evidence demonstrates that the brain can reorganize dramatically following sensory loss. Although the existence of such neuroplastic crossmodal changes is not in doubt, the functional significance of these changes remains unclear. The dominant belief is that reorganization is compensatory. However, results thus far do not unequivocally indicate that sensory deprivation results in markedly enhanced abilities in other senses. Here, we consider alternative reasons besides sensory compensation that might drive the brain to reorganize after sensory loss. One such possibility is that the cortex reorganizes not to confer functional benefits, but to avoid undesirable physiological consequences of sensory deafferentation. Empirical assessment of the validity of this and other possibilities defines a rich program for future research.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29380459,

title = {Early blindness is associated with increased volume of the uncinate fasciculus},

author = {Corinna M Bauer and Zaira Cattaneo and Lotfi B Merabet},

doi = {10.1111/ejn.13848},

issn = {1460-9568},

year  = {2018},

date = {2018-03-01},

journal = {Eur J Neurosci},

volume = {47},

number = {5},

pages = {427--432},

abstract = {Growing evidence demonstrates dramatic structural and functional neuroplastic changes in individuals born with early-onset blindness. For example, cross-modal sensory processing at the level of the occipital cortex appears to be associated with adaptive behaviors in the blind. However, detailed studies examining the structural properties of key white matter pathways in other regions of the brain remain limited. Given that blind individuals rely heavily on their sense of hearing, we examined the structural properties of two important pathways involved with auditory processing, namely the uncinate and arcuate fasciculi. High angular resolution diffusion imaging (HARDI) tractography was used to examine structural parameters (i.e., tract volume and quantitative anisotropy, or QA) of these two fasciculi in a sample of 13 early blind individuals and 14 normally sighted controls. Compared to controls, early blind individuals showed a significant increase in the volume of the left uncinate fasciculus. A small area of increased QA was also observed halfway along the right arcuate fasciculus in the blind group. These findings contribute to our knowledge regarding the broad neuroplastic changes associated with profound early blindness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29154613,

title = {The ego-moving metaphor of time relies on visual experience: No representation of time along the sagittal space in the blind},

author = {Luca Rinaldi and Tomaso Vecchi and Micaela Fantino and Lotfi B Merabet and Zaira Cattaneo},

doi = {10.1037/xge0000373},

issn = {1939-2222},

year  = {2018},

date = {2018-03-01},

journal = {J Exp Psychol Gen},

volume = {147},

number = {3},

pages = {444--450},

abstract = {In many cultures, humans conceptualize the past as behind the body and the future as in front. Whether this spatial mapping of time depends on visual experience is still not known. Here, we addressed this issue by testing early-blind participants in a space-time motor congruity task requiring them to classify a series of words as referring to the past or the future by moving their hand backward or forward. Sighted participants showed a preferential mapping between forward movements and future-words and backward movements and past-words. Critically, blind participants did not show any such preferential time-space mapping. Furthermore, in a questionnaire requiring participants to think about past and future events, blind participants did not appear to perceive the future as psychologically closer than the past, as it is the case of sighted individuals. These findings suggest that normal visual development is crucial for representing time along the sagittal space. (PsycINFO Database Record},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Zajac2017,

title = {Seed Location Impacts Whole-Brain Structural Network Comparisons between Healthy Elderly and Individuals with Alzheimer’s Disease},

author = {Lauren Zajac and Bang-Bon Koo and Corinna Bauer and Ron Killiany and },

doi = {10.3390/brainsci7040037},

issn = {2076-3425},

year  = {2017},

date = {2017-12-00},

journal = {Brain Sciences},

volume = {7},

number = {12},

publisher = {MDPI AG},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{587391,

title = {Development of the Visual Word Form Area Requires Visual Experience: Evidence from Blind Braille Readers},

author = {Judy S Kim and Shipra Kanjlia and Lotfi B. Merabet and Marina Bedny},

doi = {10.1523/JNEUROSCI.0997-17.2017},

issn = {1529-2401},

year  = {2017},

date = {2017-11-01},

journal = {J Neurosci},

volume = {37},

number = {47},

pages = {11495-11504},

abstract = {Learning to read causes the development of a letter- and word-selective region known as the visual word form area (VWFA) within the human ventral visual object stream. Why does a reading-selective region develop at this anatomical location? According to one hypothesis, the VWFA develops at the nexus of visual inputs from retinotopic cortices and linguistic input from the frontotemporal language network because reading involves extracting linguistic information from visual symbols. Surprisingly, the anatomical location of the VWFA is also active when blind individuals read Braille by touch, suggesting that vision is not required for the development of the VWFA. In this study, we tested the alternative prediction that VWFA development is in fact influenced by visual experience. We predicted that in the absence of vision, the "VWFA" is incorporated into the frontotemporal language network and participates in high-level language processing. Congenitally blind (n = 10, 9 female, 1 male) and sighted control (n = 15, 9 female, 6 male), male and female participants each took part in two functional magnetic resonance imaging experiments: (1) word reading (Braille for blind and print for sighted participants), and (2) listening to spoken sentences of different grammatical complexity (both groups). We find that in blind, but not sighted participants, the anatomical location of the VWFA responds both to written words and to the grammatical complexity of spoken sentences. This suggests that in blindness, this region takes on high-level linguistic functions, becoming less selective for reading. More generally, the current findings suggest that experience during development has a major effect on functional specialization in the human cortex.SIGNIFICANCE STATEMENT The visual word form area (VWFA) is a region in the human cortex that becomes specialized for the recognition of written letters and words. Why does this particular brain region become specialized for reading? We tested the hypothesis that the VWFA develops within the ventral visual stream because reading involves extracting linguistic information from visual symbols. Consistent with this hypothesis, we find that in congenitally blind Braille readers, but not sighted readers of print, the VWFA region is active during grammatical processing of spoken sentences. These results suggest that visual experience contributes to VWFA specialization, and that different neural implementations of reading are possible.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29061700,

title = {Development of the Visual Word Form Area Requires Visual Experience: Evidence from Blind Braille Readers},

author = {Judy S Kim and Shipra Kanjlia and Lotfi B Merabet and Marina Bedny},

doi = {10.1523/JNEUROSCI.0997-17.2017},

issn = {1529-2401},

year  = {2017},

date = {2017-11-01},

journal = {J Neurosci},

volume = {37},

number = {47},

pages = {11495--11504},

abstract = {Learning to read causes the development of a letter- and word-selective region known as the visual word form area (VWFA) within the human ventral visual object stream. Why does a reading-selective region develop at this anatomical location? According to one hypothesis, the VWFA develops at the nexus of visual inputs from retinotopic cortices and linguistic input from the frontotemporal language network because reading involves extracting linguistic information from visual symbols. Surprisingly, the anatomical location of the VWFA is also active when blind individuals read Braille by touch, suggesting that vision is not required for the development of the VWFA. In this study, we tested the alternative prediction that VWFA development is in fact influenced by visual experience. We predicted that in the absence of vision, the "VWFA" is incorporated into the frontotemporal language network and participates in high-level language processing. Congenitally blind ( = 10, 9 female, 1 male) and sighted control ( = 15, 9 female, 6 male), male and female participants each took part in two functional magnetic resonance imaging experiments: (1) word reading (Braille for blind and print for sighted participants), and (2) listening to spoken sentences of different grammatical complexity (both groups). We find that in blind, but not sighted participants, the anatomical location of the VWFA responds both to written words and to the grammatical complexity of spoken sentences. This suggests that in blindness, this region takes on high-level linguistic functions, becoming less selective for reading. More generally, the current findings suggest that experience during development has a major effect on functional specialization in the human cortex. The visual word form area (VWFA) is a region in the human cortex that becomes specialized for the recognition of written letters and words. Why does this particular brain region become specialized for reading? We tested the hypothesis that the VWFA develops within the ventral visual stream because reading involves extracting linguistic information from visual symbols. Consistent with this hypothesis, we find that in congenitally blind Braille readers, but not sighted readers of print, the VWFA region is active during grammatical processing of spoken sentences. These results suggest that visual experience contributes to VWFA specialization, and that different neural implementations of reading are possible.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28688291,

title = {Neonatal Assessment Visual European Grid (NAVEG): Unveiling neurological risk},

author = {Andrea Rossi and Marco Gnesi and Cristina Montomoli and Gaetano Chirico and Laura Malerba and Lotfi B Merabet and  and Elisa Fazzi},

doi = {10.1016/j.infbeh.2017.06.002},

issn = {1934-8800},

year  = {2017},

date = {2017-11-01},

journal = {Infant Behav Dev},

volume = {49},

pages = {21--30},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rossi2017,

title = {Neonatal Assessment Visual European Grid (NAVEG): Unveiling neurological risk},

author = {Andrea Rossi and Marco Gnesi and Cristina Montomoli and Gaetano Chirico and Laura Malerba and Lotfi B. Merabet and Elisa Fazzi},

doi = {10.1016/j.infbeh.2017.06.002},

issn = {0163-6383},

year  = {2017},

date = {2017-11-00},

journal = {Infant Behavior and Development},

volume = {49},

pages = {21--30},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28869844,

title = {Blindness and social trust: The effect of early visual deprivation on judgments of trustworthiness},

author = {C Ferrari and T Vecchi and L B Merabet and Z Cattaneo},

doi = {10.1016/j.concog.2017.08.005},

issn = {1090-2376},

year  = {2017},

date = {2017-10-01},

journal = {Conscious Cogn},

volume = {55},

pages = {156--164},

abstract = {Investigating the impact of early visual deprivation on evaluations related to social trust has received little attention to date. This is despite consistent evidence suggesting that early onset blindness may interfere with the normal development of social skills. In this study, we investigated whether early blindness affects judgments of trustworthiness regarding the actions of an agent, with trustworthiness representing the fundamental dimension in the social evaluation. Specifically, we compared performance between a group of early blind individuals with that of sighted controls in their evaluation of trustworthiness of an agent after hearing a pair of two positive or two negative social behaviors (impression formation). Participants then repeated the same evaluation following the presentation of a third (consistent or inconsistent) behavior regarding the same agent (impression updating). Overall, blind individuals tended to give similar evaluations compared to their sighted counterparts. However, they also valued positive behaviors significantly more than sighted controls when forming their impression of an agent's trustworthiness. Moreover, when inconsistent information was provided, blind individuals were more prone to revise their initial evaluation compared to controls. These results suggest that early visual deprivation may have a dramatic effect on the evaluation of social factors such as trustworthiness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28647426,

title = {Age-related changes in structural connectivity are improved using subject-specific thresholding},

author = {Corinna M Bauer and Lauren E Zajac and Bang-Bon Koo and Ronald J Killiany and Lotfi B Merabet},

doi = {10.1016/j.jneumeth.2017.06.010},

issn = {1872-678X},

year  = {2017},

date = {2017-08-01},

journal = {J Neurosci Methods},

volume = {288},

pages = {45--56},

abstract = {BACKGROUND: Deterministic diffusion tractography obtained from high angular resolution diffusion imaging (HARDI) requires user-defined quantitative anisotropy (QA) thresholds. Most studies employ a common threshold across all subjects even though there is a strong degree of individual variation within groups. We sought to explore whether it would be beneficial to use individual thresholds in order to accommodate individual variance. To do this, we conducted two independent experiments.nnMETHOD: First, tractography of the arcuate fasciculus and network connectivity measures were examined in a sample of 14 healthy participants. Second, we assessed the effects of QA threshold on group differences in network connectivity measures between healthy young (n=19) and old (n=14) individuals.nnRESULTS: The results of both experiments were significantly influenced by QA threshold. Common thresholds set too high failed to produce sufficient reconstructions in most subjects, thus decreasing the likelihood of detecting meaningful group differences. On the other hand, common thresholds set too low resulted in spurious reconstructions, providing deleterious results.nnCOMPARISON WITH EXISTING METHODS: Subject specific thresholds acquired using our QA threshold selection method (QATS) appeared to provide the most meaningful networks while ensuring that data from all subjects contributed to the analyses.nnCONCLUSIONS: Together, these results support the use of a subject-specific threshold to ensure that data from all subjects are included in the analyses being conducted.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bauer2017,

title = {Age-related changes in structural connectivity are improved using subject-specific thresholding},

author = {Corinna M. Bauer and Lauren E. Zajac and Bang-Bon Koo and Ronald J. Killiany and Lotfi B. Merabet},

doi = {10.1016/j.jneumeth.2017.06.010},

issn = {0165-0270},

year  = {2017},

date = {2017-08-00},

journal = {Journal of Neuroscience Methods},

volume = {288},

pages = {45--56},

publisher = {Elsevier BV},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28287776,

title = {Emotion processing in early blind and sighted individuals},

author = {Lucile Gamond and Tomaso Vecchi and Chiara Ferrari and Lotfi B Merabet and Zaira Cattaneo},

doi = {10.1037/neu0000360},

issn = {1931-1559},

year  = {2017},

date = {2017-07-01},

journal = {Neuropsychology},

volume = {31},

number = {5},

pages = {516--524},

abstract = {OBJECTIVE: Emotion processing is known to be mediated by a complex network of cortical and subcortical regions with evidence of specialized hemispheric lateralization within the brain. In light of prior evidence indicating that lateralization of cognitive functions (such as language) may depend on normal visual development, we investigated whether the lack of prior visual experience would have an impact on the development of specialized hemispheric lateralization in emotional processing.nnMETHOD: We addressed this issue by comparing performance in early blind and sighted controls on a dichotic listening task requiring the detection of specific emotional vocalizations (i.e., suggestive of happiness or sadness) presented independently to either ear.nnRESULTS: Consistent with previous studies, we found that sighted individuals showed enhanced detection of positive vocalizations when presented in the right ear (i.e., processed within the left hemisphere) and negative vocalizations when presented in the left ear (i.e., right hemisphere). It is interesting to note that although blind individuals were as accurate as sighted controls in detecting the valance of the vocalization, performance was not consistent with any pattern of specialized hemispheric lateralization.nnCONCLUSIONS: Overall, these results suggest that although the lack of prior visual experience may not lead to impaired emotion processing performance, the underlying neurophysiological substrate (i.e., degree of special hemispheric lateralization) may depend on normal visual development. (PsycINFO Database Record},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{587421,

title = {Enhanced verbal abilities in the congenitally blind},

author = {Valeria Occelli and Simon Lacey and Careese Stephens and Lotfi B. Merabet and K Sathian},

doi = {10.1007/s00221-017-4931-6},

issn = {1432-1106},

year  = {2017},

date = {2017-06-01},

journal = {Exp Brain Res},

volume = {235},

number = {6},

pages = {1709-1718},

abstract = {Numerous studies have found that congenitally blind individuals have better verbal memory than their normally sighted counterparts. However, it is not known whether this reflects superiority of verbal or memory abilities. In order to distinguish between these possibilities, we tested congenitally blind participants and normally sighted control participants, matched for age and education, on a range of verbal and spatial tasks. Congenitally blind participants were significantly better than sighted controls on all the verbal tasks but the groups did not differ significantly on the spatial tasks. Thus, the congenitally blind appear to have superior verbal, but not spatial, abilities. This may reflect greater reliance on verbal information and the involvement of visual cortex in language processing in the congenitally blind.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28280879,

title = {Enhanced verbal abilities in the congenitally blind},

author = {Valeria Occelli and Simon Lacey and Careese Stephens and Lotfi B Merabet and K Sathian},

doi = {10.1007/s00221-017-4931-6},

issn = {1432-1106},

year  = {2017},

date = {2017-06-01},

journal = {Exp Brain Res},

volume = {235},

number = {6},

pages = {1709--1718},

abstract = {Numerous studies have found that congenitally blind individuals have better verbal memory than their normally sighted counterparts. However, it is not known whether this reflects superiority of verbal or memory abilities. In order to distinguish between these possibilities, we tested congenitally blind participants and normally sighted control participants, matched for age and education, on a range of verbal and spatial tasks. Congenitally blind participants were significantly better than sighted controls on all the verbal tasks but the groups did not differ significantly on the spatial tasks. Thus, the congenitally blind appear to have superior verbal, but not spatial, abilities. This may reflect greater reliance on verbal information and the involvement of visual cortex in language processing in the congenitally blind.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Occelli2017,

title = {Enhanced verbal abilities in the congenitally blind},

author = {Valeria Occelli and Simon Lacey and Careese Stephens and Lotfi B. Merabet and K. Sathian},

doi = {10.1007/s00221-017-4931-6},

issn = {1432-1106},

year  = {2017},

date = {2017-06-00},

journal = {Exp Brain Res},

volume = {235},

number = {6},

pages = {1709--1718},

publisher = {Springer Science and Business Media LLC},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28941531,

title = {Disentangling How the Brain is "Wired" in Cortical (Cerebral) Visual Impairment},

author = {Lotfi B Merabet and D Luisa Mayer and Corinna M Bauer and Darick Wright and Barry S Kran},

doi = {10.1016/j.spen.2017.04.005},

issn = {1558-0776},

year  = {2017},

date = {2017-05-01},

journal = {Semin Pediatr Neurol},

volume = {24},

number = {2},

pages = {83--91},

abstract = {Cortical (cerebral) visual impairment (CVI) results from perinatal injury to visual processing structures and pathways of the brain and is the most common cause of severe visual impairment or blindness in children in developed countries. Children with CVI display a wide range of visual deficits including decreased visual acuity, impaired visual field function, as well as impairments in higher-order visual processing and attention. Together, these visual impairments can dramatically influence a child's development and well-being. Given the complex neurologic underpinnings of this condition, CVI is often undiagnosed by eye care practitioners. Furthermore, the neurophysiological basis of CVI in relation to observed visual processing deficits remains poorly understood. Here, we present some of the challenges associated with the clinical assessment and management of individuals with CVI. We discuss how advances in brain imaging are likely to help uncover the underlying neurophysiology of this condition. In particular, we demonstrate how structural and functional neuroimaging approaches can help gain insight into abnormalities of white matter connectivity and cortical activation patterns, respectively. Establishing a connection between how changes within the brain relate to visual impairments in CVI will be important for developing effective rehabilitative and education strategies for individuals living with this condition.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bauer2017b,

title = {Multimodal MR-imaging reveals large-scale structural and functional connectivity changes in profound early blindness},

author = {Corinna M. Bauer and Gabriella V. Hirsch and Lauren Zajac and Bang-Bon Koo and Olivier Collignon and Lotfi B. Merabet},

editor = {Huiguang He},

doi = {10.1371/journal.pone.0173064},

issn = {1932-6203},

year  = {2017},

date = {2017-03-22},

journal = {PLoS ONE},

volume = {12},

number = {3},

publisher = {Public Library of Science (PLoS)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28328939,

title = {Multimodal MR-imaging reveals large-scale structural and functional connectivity changes in profound early blindness},

author = {Corinna M Bauer and Gabriella V Hirsch and Lauren Zajac and Bang-Bon Koo and Olivier Collignon and Lotfi B Merabet},

doi = {10.1371/journal.pone.0173064},

issn = {1932-6203},

year  = {2017},

date = {2017-01-01},

journal = {PLoS One},

volume = {12},

number = {3},

pages = {e0173064},

abstract = {In the setting of profound ocular blindness, numerous lines of evidence demonstrate the existence of dramatic anatomical and functional changes within the brain. However, previous studies based on a variety of distinct measures have often provided inconsistent findings. To help reconcile this issue, we used a multimodal magnetic resonance (MR)-based imaging approach to provide complementary structural and functional information regarding this neuroplastic reorganization. This included gray matter structural morphometry, high angular resolution diffusion imaging (HARDI) of white matter connectivity and integrity, and resting state functional connectivity MRI (rsfcMRI) analysis. When comparing the brains of early blind individuals to sighted controls, we found evidence of co-occurring decreases in cortical volume and cortical thickness within visual processing areas of the occipital and temporal cortices respectively. Increases in cortical volume in the early blind were evident within regions of parietal cortex. Investigating white matter connections using HARDI revealed patterns of increased and decreased connectivity when comparing both groups. In the blind, increased white matter connectivity (indexed by increased fiber number) was predominantly left-lateralized, including between frontal and temporal areas implicated with language processing. Decreases in structural connectivity were evident involving frontal and somatosensory regions as well as between occipital and cingulate cortices. Differences in white matter integrity (as indexed by quantitative anisotropy, or QA) were also in general agreement with observed pattern changes in the number of white matter fibers. Analysis of resting state sequences showed evidence of both increased and decreased functional connectivity in the blind compared to sighted controls. Specifically, increased connectivity was evident between temporal and inferior frontal areas. Decreases in functional connectivity were observed between occipital and frontal and somatosensory-motor areas and between temporal (mainly fusiform and parahippocampus) and parietal, frontal, and other temporal areas. Correlations in white matter connectivity and functional connectivity observed between early blind and sighted controls showed an overall high degree of association. However, comparing the relative changes in white matter and functional connectivity between early blind and sighted controls did not show a significant correlation. In summary, these findings provide complimentary evidence, as well as highlight potential contradictions, regarding the nature of regional and large scale neuroplastic reorganization resulting from early onset blindness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Martín2016,

title = {Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity},

author = {Maria B. C. Martín and Alejandro Santos-Lozano and Juan Martín-Hernández and Alberto López-Miguel and Miguel Maldonado and Carlos Baladrón and Corinna M. Bauer and Lotfi B. Merabet},

doi = {10.3389/fpsyg.2016.01958},

issn = {1664-1078},

year  = {2016},

date = {2016-12-26},

journal = {Front. Psychol.},

volume = {7},

publisher = {Frontiers Media SA},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid27383993,

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 = {2016-07-01},

journal = {JMIR Res Protoc},

volume = {5},

number = {3},

pages = {e138},

abstract = {BACKGROUND: Despite the multiple available pharmacological and behavioral therapies for the management of chronic phantom limb pain (PLP) in lower limb amputees, treatment for this condition is still a major challenge and the results are mixed. Given that PLP is associated with maladaptive brain plasticity, interventions that promote cortical reorganization such as non-invasive brain stimulation and behavioral methods including transcranial direct current stimulation (tDCS) and mirror therapy (MT), respectively, may prove to be beneficial to control pain in PLP. Due to its complementary effects, a combination of tDCS and MT may result in synergistic effects in PLP.nnOBJECTIVE: The objective of this study is to evaluate the efficacy of tDCS and MT as a rehabilitative tool for the management of PLP in unilateral lower limb amputees.nnMETHODS: A prospective, randomized, placebo-controlled, double-blind, factorial, superiority clinical trial will be carried out. Participants will be eligible if they meet the following inclusion criteria: lower limb unilateral traumatic amputees that present PLP for at least 3 months after the amputated limb has completely healed. Participants (N=132) will be randomly allocated to the following groups: (1) active tDCS and active MT, (2) sham tDCS and active MT, (3) active tDCS and sham MT, and (4) sham tDCS and sham MT. tDCS will be applied with the anodal electrode placed over the primary motor cortex (M1) contralateral to the amputation side and the cathode over the contralateral supraorbital area. Stimulation will be applied at the same time of the MT protocol with the parameters 2 mA for 20 minutes. Pain outcome assessments will be performed at baseline, before and after each intervention session, at the end of MT, and in 2 follow-up visits. In order to assess cortical reorganization and correlate with clinical outcomes, participants will undergo functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) before and after the intervention.nnRESULTS: This clinical trial received institutional review board (IRB) approval in July of 2015 and enrollment started in December of 2015. To date 2 participants have been enrolled. The estimate enrollment rate is about 30 to 35 patients per year; thus we expect to complete enrollment in 4 years.nnCONCLUSIONS: This factorial design will provide relevant data to evaluate whether tDCS combined with MT is more effective than each therapy alone, as well as with no intervention (sham/sham) in patients with chronic PLP after unilateral lower limb amputation. In addition, this randomized clinical trial will help to investigate the neurophysiological mechanisms underlying the disease, which could potentially provide relevant findings for further management of this chronic condition and also help to optimize the use of this novel intervention.nnTRIAL REGISTRATION: Clinicaltrials.gov NCT02487966; https://clinicaltrials.gov/ct2/show/NCT02487966 (Archived by WebCite at http://www.webcitation.org/6i3GrKMyf).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Merabet2016,

title = {Characterizing Visual Field Deficits in Cerebral/Cortical Visual Impairment (CVI) Using Combined Diffusion Based Imaging and Functional Retinotopic Mapping: A Case Study},

author = {Lotfi B. Merabet and Kathryn J. Devaney and Corinna M. Bauer and Aparna Panja and Gena Heidary and David C. Somers},

doi = {10.3389/fnsys.2016.00013},

issn = {1662-5137},

year  = {2016},

date = {2016-02-25},

journal = {Front. Syst. Neurosci.},

volume = {10},

publisher = {Frontiers Media SA},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid28082927,

title = {Cerebral versus Ocular Visual Impairment: The Impact on Developmental Neuroplasticity},

author = {Maria B C Martín and Alejandro Santos-Lozano and Juan Martín-Hernández and Alberto López-Miguel and Miguel Maldonado and Carlos Baladrón and Corinna M Bauer and Lotfi B Merabet},

doi = {10.3389/fpsyg.2016.01958},

issn = {1664-1078},

year  = {2016},

date = {2016-01-01},

journal = {Front Psychol},

volume = {7},

pages = {1958},

abstract = {Cortical/cerebral visual impairment (CVI) is clinically defined as significant visual dysfunction caused by injury to visual pathways and structures occurring during early perinatal development. Depending on the location and extent of damage, children with CVI often present with a myriad of visual deficits including decreased visual acuity and impaired visual field function. Most striking, however, are impairments in visual processing and attention which have a significant impact on learning, development, and independence. Within the educational arena, current evidence suggests that strategies designed for individuals with ocular visual impairment are not effective in the case of CVI. We propose that this variance may be related to differences in compensatory neuroplasticity related to the type of visual impairment, as well as underlying alterations in brain structural connectivity. We discuss the etiology and nature of visual impairments related to CVI, and how advanced neuroimaging techniques (i.e., diffusion-based imaging) may help uncover differences between ocular and cerebral causes of visual dysfunction. Revealing these differences may help in developing future strategies for the education and rehabilitation of individuals living with visual impairment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid26941619,

title = {Characterizing Visual Field Deficits in Cerebral/Cortical Visual Impairment (CVI) Using Combined Diffusion Based Imaging and Functional Retinotopic Mapping: A Case Study},

author = {Lotfi B Merabet and Kathryn J Devaney and Corinna M Bauer and Aparna Panja and Gena Heidary and David C Somers},

doi = {10.3389/fnsys.2016.00013},

issn = {1662-5137},

year  = {2016},

date = {2016-01-01},

journal = {Front Syst Neurosci},

volume = {10},

pages = {13},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}