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 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.

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 Niewidzenie a kompetencje pragmatyczne w komunikacji

2019 ◽  
pp. 189-210
Author(s):  
Kornelia Czerwińska ◽  
Agnieszka Piskorska
Keyword(s):  
Reading Comprehension ◽  
Foreign Language ◽  
Visual Experience ◽  
Educational Development ◽  
Pragmatic Competence ◽  
Linguistic Terms ◽  
Comprehension Task ◽  
Congenitally Blind ◽  
Blind Individuals ◽  
Basic Level

The paper argues that gaps in knowledge attested in congenitally blind individuals may negatively affect their performance in foreign language tasks testing reading comprehension. Characteristics of a blind learner at various stages of cognitive and educational development are presented, with focus on gaps in knowledge resulting from sight impairment. The concept of pragmatic competence is first explained generally in reference to communication and then it is applied to a case of a comprehension task taken from an EFL exam (Polish “matura”, basic level). An analysis of the text indicates that despite being relatively simple in linguistic terms, comprehension tasks may pose a significant processing challenge to blind students due to a large amount of implicitly communicated information dependent on visual experience.

scholarly journals Naturalistic audio-movies reveal common spatial organization across “visual” cortices of different blind individuals

2021 ◽  
Author(s):  
Elizabeth Musz ◽  
Rita Loiotile ◽  
Janice Chen ◽  
Marina Bedny
Keyword(s):  
Visual Cortex ◽  
Visual Information ◽  
Spatial Organization ◽  
Activity Patterns ◽  
Auditory Stimuli ◽  
Spatial Activity ◽  
Pattern Similarity ◽  
Congenitally Blind ◽  
Visual Cortices ◽  
Blind Individuals

AbstractOccipital cortices of different sighted people contain analogous maps of visual information (e.g., foveal vs. peripheral space). In congenital blindness, “visual” cortices enhance responses to nonvisual stimuli. Do deafferented visual cortices of different blind people represent common informational maps? We leverage a naturalistic stimulus paradigm and inter-subject pattern similarity analysis to address this question. Blindfolded sighted (S, n=22) and congenitally blind (CB, n=22) participants listened to three auditory excerpts from movies; a naturalistic spoken narrative; and matched degraded auditory stimuli (i.e., shuffled sentences and backwards speech) while undergoing fMRI scanning. In a parcel-based whole brain analysis, we measured the spatial activity patterns evoked by each unique, ten-second segment of each auditory clip. We then compared each subject’s spatial pattern to that of all other subjects in the same group (CB or S) within and across segments. In both blind and sighted groups, segments of meaningful auditory stimuli produced distinctive patterns of activity that were shared across individuals. Crucially, only in the CB group, this segment-specific, cross-subject pattern similarity effect emerged in visual cortex, but only for meaningful naturalistic stimuli and not backwards speech. These results suggest that spatial activity patterns within deafferented visual cortices encode meaningful, segment-level information contained in naturalistic auditory stimuli, and that these representations are spatially organized in a similar fashion across blind individuals.Significance StatementRecent neuroimaging studies show that the so-called “visual” cortices activate during non-visual tasks in people who are born blind. Do the visual cortices of people who are born blind develop similar representational maps? While congenitally blind individuals listened to naturalistic auditory stimuli (i.e., sound clips from movies), distinct timepoints within each stimulus elicited unique spatial activity patterns in visual cortex, and these patterns were shared across different people. These findings suggest that in blindness, the visual cortices encode meaningful information embedded in naturalistic auditory signals in a spatially distributed manner, and that a common representational map can emerge in visual cortex independent of visual experience.

scholarly journals Visual experience is not necessary for the development of face-selectivity in the lateral fusiform gyrus

2020 ◽  
Vol 117 (37) ◽  
pp. 23011-23020 ◽  
Author(s):  
N. Apurva Ratan Murty ◽  
Santani Teng ◽  
David Beeler ◽  
Anna Mynick ◽  
Aude Oliva ◽  
...  
Keyword(s):  
Visual Experience ◽  
Fusiform Gyrus ◽  
Fusiform Face Area ◽  
Face Area ◽  
Haptic Exploration ◽  
Cortical Responses ◽  
Congenitally Blind ◽  
Face Selectivity ◽  
3D Printed ◽  
Blind Individuals

The fusiform face area responds selectively to faces and is causally involved in face perception. How does face-selectivity in the fusiform arise in development, and why does it develop so systematically in the same location across individuals? Preferential cortical responses to faces develop early in infancy, yet evidence is conflicting on the central question of whether visual experience with faces is necessary. Here, we revisit this question by scanning congenitally blind individuals with fMRI while they haptically explored 3D-printed faces and other stimuli. We found robust face-selective responses in the lateral fusiform gyrus of individual blind participants during haptic exploration of stimuli, indicating that neither visual experience with faces nor fovea-biased inputs is necessary for face-selectivity to arise in the lateral fusiform gyrus. Our results instead suggest a role for long-range connectivity in specifying the location of face-selectivity in the human brain.

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