scholarly journals Dissociated face- and word-selective intracerebral responses in the human ventral occipito-temporal cortex

2020 ◽  
Author(s):  
Simen Hagen ◽  
Aliette Lochy ◽  
Corentin Jacques ◽  
Louis Maillard ◽  
Sophie Colnat-Coulbois ◽  
...  
Keyword(s):  
Neural Networks ◽  
Word Processing ◽  
Temporal Cortex ◽  
Modern Human ◽  
Visual Signals ◽  
Hemispheric Dominance ◽  
Visual Responses ◽  
Neural Responses ◽  
Large Group ◽  
Depth Electrodes

AbstractThe extent to which faces and written words share neural circuitry in the human brain is actively debated. Here we compared face-selective and word-selective responses in a large group of patients (N = 37) implanted with intracerebral depth electrodes in the ventral occipito-temporal cortex (VOTC). Both face-selective (i.e., significantly different responses to faces vs. nonface visual objects) and word-selective (i.e., significantly different responses to words vs. pseudofonts) neural activity is isolated through frequency-tagging. Critically, this sensitive approach allows to objectively quantify category-selective neural responses and disentangle them from general visual responses. About 70% of significant contacts show either only face-selectivity or only word-selectivity, with the expected right and left hemispheric dominance, respectively. Spatial dissociations are also found within core regions of face and word processing, with a medio-lateral dissociation in the fusiform gyrus (FG) and surrounding sulci, while a postero-anterior dissociation is found in the inferior occipital gyrus (IOG). Only 30% of the significant contacts show both face- and word-selective responses. Critically, in these contacts, across the VOTC or in the FG and surrounding sulci, between-category selective-amplitudes (faces vs. words) showed no-to-weak correlations, despite strong correlations in both the within-category selective amplitudes (face-face, word-word) and the general visual responses to words and faces. Overall, we conclude that category-selectivity for faces and written words is largely dissociated in the human VOTC.Significance StatementIn modern human societies, faces and written words have become arguably the most significant stimuli of the visual environment. Despite extensive research in neuropsychology, electroencephalography and neuroimaging over the past three decades, whether these two types of visual signals are recognized by similar or dissociated processes and neural networks remains unclear. Here we provide an original contribution to this outstanding scientific issue by directly comparing frequency-tagged face- and word-selective neural responses in a large group of epileptic patients implanted with intracerebral electrodes covering the ventral occipito-temporal cortex. While general visual responses to words and faces show significant overlap, the respective category-selective responses are neatly dissociated in spatial location and magnitude, pointing to largely dissociated processes and neural networks.

scholarly journals Dissociated face- and word-selective intracerebral responses in the human ventral occipito-temporal cortex

2021 ◽  
Author(s):  
Simen Hagen ◽  
Aliette Lochy ◽  
Corentin Jacques ◽  
Louis Maillard ◽  
Sophie Colnat-Coulbois ◽  
...  
Keyword(s):  
Neural Activity ◽  
Word Processing ◽  
Temporal Cortex ◽  
Neural Circuitry ◽  
Hemispheric Dominance ◽  
Strong Correlations ◽  
Visual Responses ◽  
Neural Responses ◽  
Visual Objects ◽  
Face Selectivity

AbstractThe extent to which faces and written words share neural circuitry in the human brain is actively debated. Here, we compare face-selective and word-selective responses in a large group of patients (N = 37) implanted with intracerebral electrodes in the ventral occipito-temporal cortex (VOTC). Both face-selective (i.e., significantly different responses to faces vs. non-face visual objects) and word-selective (i.e., significantly different responses to words vs. pseudofonts) neural activity is isolated with frequency-tagging. Critically, this sensitive approach allows to objectively quantify category-selective neural responses and disentangle them from general visual responses. About 70% of significant electrode contacts show either face-selectivity or word-selectivity only, with the expected right and left hemispheric dominance, respectively. Spatial dissociations are also found within core regions of face and word processing, with a medio-lateral dissociation in the fusiform gyrus (FG) and surrounding sulci, respectively. In the 30% of overlapping face- and word-selective contacts across the VOTC or in the FG and surrounding sulci, between-category-selective amplitudes (faces vs. words) show no-to-weak correlations, despite strong correlations in both the within-category-selective amplitudes (face–face, word–word) and the general visual responses to words and faces. Overall, these observations support the view that category-selective circuitry for faces and written words is largely dissociated in the human adult VOTC.

scholarly journals A neural signature of automatic lexical access in bilinguals

2021 ◽  
Author(s):  
Sabrina Aristei ◽  
Aliette Lochy ◽  
Bruno Rossion ◽  
Christine Schiltz
Keyword(s):  
Visual Processing ◽  
Word Processing ◽  
Visual Stimulation ◽  
Temporal Cortex ◽  
Visual Responses ◽  
Beneficial Effects ◽  
Brain Responses ◽  
Neural Signature ◽  
Language Exposure ◽  
Cross Language

Bilingualism is often associated with beneficial effects on cognitive control and top-down processes. The present study aimed at bypassing these processes to assess automatic visual word recognition in bilinguals. Using fast periodic visual stimulation, we recorded frequency-tagged word-selective EEG responses in French monolinguals and late bilinguals (German native, French as second language). Words were presented centrally within rapid (10 Hz) sequences of letter strings varying in word-likeness, i.e., consonant strings, non-words, pseudo-words, while participants performed an orthogonal task. Automatic word-selective brain responses in the occipito-temporal cortex arose almost exclusively for the languages mastered by participants: two in bilinguals vs. one in monolinguals. Importantly, the amplitude of bilinguals responses to words within consonant strings were unaffected by the native vs. late-learnt status of the language. Furthermore, for all and only known languages, word-selective responses were reduced by embedding them in pseudo-words relative to non-words, both derived from the same language as the words. This word-likeness effect highlights the lexical nature of the recorded brain visual responses. A cross-language word-likeness effect was observed only in bilinguals and only with pseudo-words derived from the native language, indicating an experience-based tuning to language. Taken together these findings indicate that the amount of exposure to a language determines the engagement of neural resources devoted to word processing in the occipito-temporal visual cortex. We conclude that automatic lexical coding occurs at early visual processing in bilinguals and monolinguals alike, and that language exposure determines the competition strength of a language.

scholarly journals Developmental Changes in Visual Responses to Social Interactions

2019 ◽  
Author(s):  
Jon Walbrin ◽  
Ioana Mihai ◽  
Julia Landsiedel ◽  
Kami Koldewyn
Keyword(s):  
Social Interactions ◽  
Temporal Cortex ◽  
Developmental Trend ◽  
List Type ◽  
Visual Responses ◽  
Neural Responses ◽  
Older Children ◽  
Face Area ◽  
Extrastriate Body Area ◽  
The Right

AbstractRecent evidence demonstrates that a region of the posterior superior temporal sulcus (pSTS) is selective to visually observed social interactions in adults. In contrast, we know comparatively little about neural responses to social interactions in children. Here, we used fMRI to ask whether the pSTS would be ‘tuned’ to social interactions in children at all, and if so, how selectivity might differ from adults. This was investigated not only in the pSTS, but also in socially-tuned regions in neighbouring temporal cortex: extrastriate body area (EBA), face-selective STS (STS-F), fusiform face area (FFA), and temporo-parietal junction (TPJ-M).Both children and adults showed selectivity to social interaction within right pSTS, while only adults showed selectivity on the left. Adults also showed both more focal and greater selectivity than children (6–12 years) bilaterally. Exploratory sub-group analyses showed that younger children (6–8 years), but not older children (9-12), are less selective than adults on the right, while there was a developmental trend (adults > older > younger) in left pSTS. These results suggest that, over development, the neural response to social interactions is characterized by increasingly more selective, more focal and more bilateral pSTS responses, a process that likely continues into adolescence.HighlightsChildren show less interaction selectivity in the pSTS than adultsAdults show bilateral pSTS selectivity, while children are more right-lateralizedExploratory findings suggest interaction selectivity in pSTS is more focally tuned in adults

Using Convolutional Neural Networks to measure the contribution of visual features to the representation of object animacy in the brain

2019 ◽  
Author(s):  
Sushrut Thorat
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Temporal Cortex ◽  
Large Degree ◽  
Visual Features ◽  
Visual Feature ◽  
Visual Stream ◽  
Feature Information ◽  
Ventral Visual Stream ◽  
Animal Images

A mediolateral gradation in neural responses for images spanning animals to artificial objects is observed in the ventral temporal cortex (VTC). Which information streams drive this organisation is an ongoing debate. Recently, in Proklova et al. (2016), the visual shape and category (“animacy”) dimensions in a set of stimuli were dissociated using a behavioural measure of visual feature information. fMRI responses revealed a neural cluster (extra-visual animacy cluster - xVAC) which encoded category information unexplained by visual feature information, suggesting extra-visual contributions to the organisation in the ventral visual stream. We reassess these findings using Convolutional Neural Networks (CNNs) as models for the ventral visual stream. The visual features developed in the CNN layers can categorise the shape-matched stimuli from Proklova et al. (2016) in contrast to the behavioural measures used in the study. The category organisations in xVAC and VTC are explained to a large degree by the CNN visual feature differences, casting doubt over the suggestion that visual feature differences cannot account for the animacy organisation. To inform the debate further, we designed a set of stimuli with animal images to dissociate the animacy organisation driven by the CNN visual features from the degree of familiarity and agency (thoughtfulness and feelings). Preliminary results from a new fMRI experiment designed to understand the contribution of these non-visual features are presented.

scholarly journals Lateralızatıon of Non-Word Processıng in Monolınguals

2020 ◽  
Vol 15 ◽  
pp. 185-190
Author(s):  
Filiz Mergen ◽  
Gulmira Kuruoglu
Keyword(s):  
Lexical Decision ◽  
Lexical Decision Task ◽  
Left Hemisphere ◽  
Word Processing ◽  
Lexical Processing ◽  
Response Times ◽  
Hemispheric Dominance ◽  
Decision Task ◽  
Visual Hemifield ◽  
Overwhelming Evidence

A great bulk of research in the psycholinguistic literature has been dedicated to hemispheric organization of words. An overwhelming evidence suggests that the left hemisphere is primarily responsible for lexical processing. However, non-words, which look similar to real words but lack meaningful associations, is underrepresented in the laterality literature. This study investigated the lateralization of Turkish non-words. Fifty-three Turkish monolinguals performed a lexical decision task in a visual hemifield paradigm. An analysis of their response times revealed left-hemispheric dominance for non-words, adding further support to the literature. The accuracy of their answers, however, were comparable regardless of the field of presentation. The results were discussed in light of the psycholinguistic word processing views.

scholarly journals The nature of the animacy organization in human ventral temporal cortex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Sushrut Thorat ◽  
Daria Proklova ◽  
Marius V Peelen
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Temporal Cortex ◽  
Behavioral Experiments ◽  
Diagnostic Features ◽  
Social Agents ◽  
Independent Components ◽  
Ventral Temporal Cortex ◽  
Organizing Principles ◽  
The Continuum

The principles underlying the animacy organization of the ventral temporal cortex (VTC) remain hotly debated, with recent evidence pointing to an animacy continuum rather than a dichotomy. What drives this continuum? According to the visual categorization hypothesis, the continuum reflects the degree to which animals contain animal-diagnostic features. By contrast, the agency hypothesis posits that the continuum reflects the degree to which animals are perceived as (social) agents. Here, we tested both hypotheses with a stimulus set in which visual categorizability and agency were dissociated based on representations in convolutional neural networks and behavioral experiments. Using fMRI, we found that visual categorizability and agency explained independent components of the animacy continuum in VTC. Modeled together, they fully explained the animacy continuum. Finally, clusters explained by visual categorizability were localized posterior to clusters explained by agency. These results show that multiple organizing principles, including agency, underlie the animacy continuum in VTC.

Functional Role of the Left Ventral Occipito-Temporal Cortex in Reading

2013 ◽  
pp. 192-200
Author(s):  
Geqi Qi ◽  
Jinglong Wu
Keyword(s):  
Functional Properties ◽  
Functional Role ◽  
Word Processing ◽  
Functional Organization ◽  
Temporal Cortex ◽  
Visual Word ◽  
Word Form ◽  
Considerable Debate ◽  
Two Sides

The sensitivity of the left ventral occipito-temporal (vOT) cortex to visual word processing has triggered a considerable debate about the functional role of this region in reading. The debate rests largely on the issue whether this particular region is specifically dedicated to reading and the extraction of invariant visual word form. A lot of studies have been conducted to provide evidences supporting or against the functional specialization of this region. However, the trend is showing that the different functional properties proposed by the two kinds of view are not in conflict with each other, but instead show different sides of the same fact. Here, the authors focus on two questions: firstly, where do the two views conflict, and secondly, how do they fit with each other on a larger framework of functional organization in object vision pathway? This review evaluates findings from the two sides of the debate for a broader understanding of the functional role of the left vOT cortex.

A Functional Neuroimaging Description of Two Deep Dyslexic Patients

1998 ◽  
Vol 10 (3) ◽  
pp. 303-315 ◽  
Author(s):  
C. J. Price ◽  
D. Howard ◽  
K. Patterson ◽  
E. A. Warburton ◽  
K. J. Friston ◽  
...  
Keyword(s):  
Left Hemisphere ◽  
Word Processing ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Broca's Area ◽  
Enhanced Activity ◽  
Left Posterior ◽  
Deep Dyslexia ◽  
The Right

Deep dyslexia is a striking reading disorder that results from left-hemisphere brain damage and is characterized by semantic errors in reading single words aloud (e.g., reading spirit as whisky). Two types of explanation for this syndrome have been advanced. One is that deep dyslexia results from a residual left-hemisphere reading system that has lost the ability to pronounce a printed word without reference to meaning. The second is that deep dyslexia reflects right-hemisphere word processing. Although previous attempts to adjudicate between these hypotheses have been inconclusive, the controversy can now be addressed by mapping functional anatomy. In this study, we demonstrate that reading by two deep dyslexic patients (CJ and JG) involves normal or enhanced activity in spared left-hemisphere regions associated with naming (Broca's area and the left posterior inferior temporal cortex) and with the meanings of words (the left posterior temporo-parietal cortex and the left anterior temporal cortex). In the right-hemisphere homologues of these regions, there was inconsistent activation within the normal group and between the deep dyslexic patients. One (CJ) showed enhanced activity (relative to the normals) in the right anterior inferior temporal cortex, the other (JG) in the right Broca's area, and both in the right frontal operculum. Although these differential right-hemisphere activations may have influenced the reading behavior of the patients, their activation patterns primarily reflect semantic and phonological systems in spared regions of the left hemisphere. These results preclude an explanation of deep dyslexia in terms of purely right-hemisphere word processing.

Distinct unimodal and multimodal regions for word processing in the left temporal cortex

NeuroImage ◽  
2004 ◽  
Vol 23 (4) ◽  
pp. 1256-1270 ◽  
Author(s):  
Laurent Cohen ◽  
Antoinette Jobert ◽  
Denis Le Bihan ◽  
Stanislas Dehaene
Keyword(s):  
Word Processing ◽  
Temporal Cortex

scholarly journals Attractor dynamics in networks with learning rules inferred from in vivo data

2017 ◽  
Author(s):  
Ulises Pereira ◽  
Nicolas Brunel
Keyword(s):  
Neural Network ◽  
Hebbian Learning ◽  
Temporal Cortex ◽  
Memory Storage ◽  
Inferior Temporal Cortex ◽  
Association Cortex ◽  
Visual Responses ◽  
Neural Network Models ◽  
Firing Rates ◽  
Learning Rules

AbstractThe attractor neural network scenario is a popular scenario for memory storage in association cortex, but there is still a large gap between models based on this scenario and experimental data. We study a recurrent network model in which both learning rules and distribution of stored patterns are inferred from distributions of visual responses for novel and familiar images in inferior temporal cortex (ITC). Unlike classical attractor neural network models, our model exhibits graded activity in retrieval states, with distributions of firing rates that are close to lognormal. Inferred learning rules are close to maximizing the number of stored patterns within a family of unsupervised Hebbian learning rules, suggesting learning rules in ITC are optimized to store a large number of attractor states. Finally, we show that there exists two types of retrieval states: one in which firing rates are constant in time, another in which firing rates fluctuate chaotically.

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