scholarly journals Emergence of categorical face perception after extended early-onset blindness

2017 ◽  
Vol 114 (23) ◽  
pp. 6139-6143 ◽  
Author(s):  
Tapan K. Gandhi ◽  
Amy Kalia Singh ◽  
Piyush Swami ◽  
Suma Ganesh ◽  
Pawan Sinha
Keyword(s):  
Face Perception ◽  
Skill Acquisition ◽  
Early Onset ◽  
Critical Period ◽  
Natural Images ◽  
Neural Basis ◽  
Blind Child ◽  
Congenitally Blind ◽  
Blind Individuals

It is unknown whether the ability to visually distinguish between faces and nonfaces is subject to a critical period during development. Would a congenitally blind child who gains sight several years after birth be able to acquire this skill? This question has remained unanswered because of the rarity of cases of late sight onset. We had the opportunity to work with five early-blind individuals who gained sight late in childhood after treatment for dense bilateral cataracts. We tested their ability to categorize patterns as faces, using natural images that spanned a spectrum of face semblance. The results show that newly sighted individuals are unable to distinguish between faces and nonfaces immediately after sight onset, but improve markedly in the following months. These results demonstrate preserved plasticity for acquiring face/nonface categorization ability even late in life, and set the stage for investigating the informational and neural basis of this skill acquisition.

Mannerisms in the Congenitally Blind Child

1972 ◽  
Vol 66 (9) ◽  
pp. 297-302
Author(s):  
John J. Knight
Keyword(s):  
Physical Activity ◽  
Critical Period ◽  
Early Infancy ◽  
Coping Behaviors ◽  
Gross Motor ◽  
Blind Child ◽  
Motor Behaviors ◽  
Congenitally Blind ◽  
Critical Period Of Development

□ In summary: (1) Mannerisms are behaviors that the blind child uses to cope with tensions created by situations of frustration, fear, excitement, stimulation deficit, physical activity deprivation, insecurity, etc. (2) The blind child resorts to mannerisms, which are non-instrumental gross motor behaviors learned during early infancy, when he does not have a set of strong instrumental coping behaviors. (3) The blind child's lack of vision impedes the development of essential instrumental behaviors that are learned during infancy, such as reaching and crawling. (4) The blind infant must be given assistance which will enable him to develop each of his instrumental behaviors more completely, especially during the critical period of development for each behavior.

scholarly journals Reading Modality Modifies Reading Network: Insights from Neural basis of Braille in Proficient Blind Readers

2021 ◽  
Author(s):  
Mengyu Tian ◽  
Elizabeth J. Saccone ◽  
Judy S. Kim ◽  
Shipra Kanjlia ◽  
Marina Bedny
Keyword(s):  
Sensory Modality ◽  
Word Form ◽  
Neural Basis ◽  
Cortical Function ◽  
Congenitally Blind ◽  
Posterior Parietal ◽  
Physical Features ◽  
Blind Individuals ◽  
Parietal Cortices ◽  
Visual Reading

The neural basis of reading is highly consistent across a variety of languages and visual scripts. An unanswered question is whether the sensory modality of symbols influences the neural basis of reading. According to the modality-invariant view, reading depends on the same neural mechanisms regardless of the sensory input modality. Consistent with this idea, previous studies find that the visual word form area (VWFA) within the ventral occipitotemporal cortex (vOTC) is active when blind individuals read Braille by touch. However, connectivity-based theories of brain function suggest that the neural entry point of written symbols (touch vs. vision) may influence the neural architecture of reading. We compared the neural basis of the visual print (sighted n=15) and tactile Braille (congenitally blind n=19) in proficient readers using analogous reading and listening tasks. Written stimuli varied in word-likeness from real words to consonant strings and non-letter shape strings. Auditory stimuli consisted of words and backward speech sounds. Consistent with prior work, vOTC was active during Braille and visual reading. However, in sighted readers, visual print elicited a posterior/anterior vOTC word-form gradient: anterior vOTC preferred larger orthographic units (words), middle vOTC preferring consonant strings, and posterior vOTC responded to shapes (i.e., lower-level physical features). No such gradient was observed in blind readers of Braille. Consistent with connectivity predictions, in blind Braille readers, posterior parietal cortices (PPC) and parieto-occipital areas were recruited to a greater degree and PPC contained word-preferring patches. Lateralization of Braille in blind readers was predicted by laterality of spoken language, as well as by reading hand. These results suggested that the neural basis of reading is influenced by symbol modality and support connectivity-based views of cortical function.

scholarly journals Absence of visual experience modifies the neural basis of numerical thinking

2016 ◽  
Vol 113 (40) ◽  
pp. 11172-11177 ◽  
Author(s):  
Shipra Kanjlia ◽  
Connor Lane ◽  
Lisa Feigenson ◽  
Marina Bedny
Keyword(s):  
Sentence Comprehension ◽  
Visual Experience ◽  
Numerical Cognition ◽  
Neural Basis ◽  
Frontoparietal Network ◽  
Dorsolateral Prefrontal ◽  
Congenitally Blind ◽  
Visual Cortices ◽  
Math Calculation ◽  
Blind Individuals

In humans, the ability to reason about mathematical quantities depends on a frontoparietal network that includes the intraparietal sulcus (IPS). How do nature and nurture give rise to the neurobiology of numerical cognition? We asked how visual experience shapes the neural basis of numerical thinking by studying numerical cognition in congenitally blind individuals. Blind (n = 17) and blindfolded sighted (n = 19) participants solved math equations that varied in difficulty (e.g., 27 − 12 = x vs. 7 − 2 = x), and performed a control sentence comprehension task while undergoing fMRI. Whole-cortex analyses revealed that in both blind and sighted participants, the IPS and dorsolateral prefrontal cortices were more active during the math task than the language task, and activity in the IPS increased parametrically with equation difficulty. Thus, the classic frontoparietal number network is preserved in the total absence of visual experience. However, surprisingly, blind but not sighted individuals additionally recruited a subset of early visual areas during symbolic math calculation. The functional profile of these “visual” regions was identical to that of the IPS in blind but not sighted individuals. Furthermore, in blindness, number-responsive visual cortices exhibited increased functional connectivity with prefrontal and IPS regions that process numbers. We conclude that the frontoparietal number network develops independently of visual experience. In blindness, this number network colonizes parts of deafferented visual cortex. These results suggest that human cortex is highly functionally flexible early in life, and point to frontoparietal input as a mechanism of cross-modal plasticity in blindness.

scholarly journals Neural basis of approximate number system develops independent of visual experience

2019 ◽  
Author(s):  
Shipra Kanjlia ◽  
Lisa Feigenson ◽  
Marina Bedny
Keyword(s):  
Visual Experience ◽  
Human Life ◽  
Number System ◽  
Approximate Number System ◽  
Neural Basis ◽  
Neuronal Populations ◽  
Number Representations ◽  
Population Codes ◽  
Congenitally Blind ◽  
Blind Individuals

AbstractThinking about numerical quantities is an integral part of daily human life that is supported by the intraparietal sulcus (IPS). The IPS is recruited during mathematical calculation and neuronal populations within the IPS code for the quantity of items in a set. Is the developmental basis of IPS number representations rooted in visual experience? We asked if the IPS possesses population codes for auditory quantities in sighted individuals and, critically, whether it does in the absence of any visual experience in congenitally blind individuals. We found that sequences of 4, 8, 16 and 32 tones each elicited unique patterns of fMRI activity in the IPS of both sighted and congenitally blind individuals, such that the quantity a participant heard on a given trial could be reliably predicted based on the pattern of observed IPS activity. This finding suggests that the IPS number system is resilient to dramatic changes in sensory experience.

scholarly journals A sensitive period in the neural phenotype of language in blind individuals

2019 ◽  
Author(s):  
Rashi Pant ◽  
Shipra Kanjlia ◽  
Marina Bedny
Keyword(s):  
Sentence Processing ◽  
No Reduction ◽  
Memory Task ◽  
Sensitive Period ◽  
Neural Basis ◽  
Congenitally Blind ◽  
Visual Cortices ◽  
Temporal Language ◽  
Blind Individuals ◽  
Language Network

ABSTRACTIn congenital blindness, “visual” cortices respond to linguistic information, and fronto-temporal language networks are less left-lateralized. Does this plasticity follow a sensitive period? We tested this by comparing the neural basis of sentence processing in two experiments with adult-onset blind (AB, n=16), congenitally blind (CB, n=22) and blindfolded sighted controls (n=18). In Experiment 1, participants made semantic judgments for spoken sentences and solved math equations in a control condition. In Experiment 2, participants answered “who did what to whom” questions for grammatically complex (with syntactic movement) and grammatically simpler sentences. In a control condition, participants performed a memory task with lists of non-words. In both experiments, visual cortices of CB and AB but not sighted participants responded more to sentences than control conditions, but the effect was much larger in the CB group. Crucially, only the “visual” cortex of CB participants responded to grammatical complexity. Unlike the CB group, the AB group showed no reduction in left-lateralization of fronto-temporal language network relative to the sighted. These results suggest that blindness during development modifies the neural basis of language, and this effect follows a sensitive period.

scholarly journals Occipital Cortex of Blind Individuals Is Functionally Coupled with Executive Control Areas of Frontal Cortex

2015 ◽  
Vol 27 (8) ◽  
pp. 1633-1647 ◽  
Author(s):  
Ben Deen ◽  
Rebecca Saxe ◽  
Marina Bedny
Keyword(s):  
Working Memory ◽  
Functional Connectivity ◽  
Sentence Comprehension ◽  
Memory Load ◽  
Memory Task ◽  
Occipital Cortex ◽  
Memory Systems ◽  
Functional Responses ◽  
Congenitally Blind ◽  
Blind Individuals

In congenital blindness, the occipital cortex responds to a range of nonvisual inputs, including tactile, auditory, and linguistic stimuli. Are these changes in functional responses to stimuli accompanied by altered interactions with nonvisual functional networks? To answer this question, we introduce a data-driven method that searches across cortex for functional connectivity differences across groups. Replicating prior work, we find increased fronto-occipital functional connectivity in congenitally blind relative to blindfolded sighted participants. We demonstrate that this heightened connectivity extends over most of occipital cortex but is specific to a subset of regions in the inferior, dorsal, and medial frontal lobe. To assess the functional profile of these frontal areas, we used an n-back working memory task and a sentence comprehension task. We find that, among prefrontal areas with overconnectivity to occipital cortex, one left inferior frontal region responds to language over music. By contrast, the majority of these regions responded to working memory load but not language. These results suggest that in blindness occipital cortex interacts more with working memory systems and raise new questions about the function and mechanism of occipital plasticity.

scholarly journals Spatial navigation by congenitally blind individuals

2015 ◽  
Vol 7 (1) ◽  
pp. 37-58 ◽  
Author(s):  
Victor R. Schinazi ◽  
Tyler Thrash ◽  
Daniel-Robert Chebat
Keyword(s):  
Spatial Navigation ◽  
Congenitally Blind ◽  
Blind Individuals

scholarly journals Neural basis of contextual modulation on categorical face perception

2010 ◽  
Vol 9 (8) ◽  
pp. 456-456
Author(s):  
M. Meng ◽  
T. Cherian ◽  
P. Sinha
Keyword(s):  
Face Perception ◽  
Neural Basis ◽  
Contextual Modulation

scholarly journals A critical period for number-related plasticity in the visual cortex of blind individuals

2017 ◽  
Vol 17 (10) ◽  
pp. 644
Author(s):  
Shipra Kanjlia ◽  
Lisa Feigenson ◽  
Marina Bedny
Keyword(s):  
Visual Cortex ◽  
Critical Period ◽  
Blind Individuals

scholarly journals Shared understanding of color among congenitally blind and sighted adults

2020 ◽  
Author(s):  
Judy Sein Kim ◽  
Brianna Aheimer ◽  
Veronica Montane Manrara ◽  
Marina Bedny
Keyword(s):  
Visual Experience ◽  
Natural Kinds ◽  
Shared Understanding ◽  
Linguistic Communication ◽  
Causal Explanations ◽  
Stop Sign ◽  
Congenitally Blind ◽  
Novel Objects ◽  
Blind Individuals

Empiricist philosophers such as Locke famously argued that people born blind could only acquire shallow, fragmented facts about color. Contrary to this intuition, we report that blind and sighted people share an in-depth understanding of color, despite disagreeing about arbitrary color facts. Relative to the sighted, blind individuals are less likely to generate ‘yellow’ for banana and ‘red’ for stop-sign. However, blind and sighted adults are equally likely to infer that two bananas (natural kinds) and two stop-signs (artifacts with functional colors) are more likely to have the same color than two cars (artifacts with non-functional colors), make similar inferences about novel objects’ colors, and provide similar causal explanations. We argue that people develop inferentially-rich and intuitive “theories” of color regardless of visual experience. Linguistic communication is more effective at aligning people’s theories than their knowledge of verbal facts.

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