scholarly journals A precursor of reading: Neural responses to letters strings in the untrained primate inferior temporal cortex predict word recognition behavior

2019 ◽  
Vol 19 (10) ◽  
pp. 172b
Author(s):  
Rishi Rajalingham ◽  
Kohitij Kar ◽  
Sachi Sanghavi ◽  
Stanislas Dehaene ◽  
James J DiCarlo
Keyword(s):  
Word Recognition ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Responses

scholarly journals Zero-shot neural decoding of visual categories without prior exemplars

2019 ◽  
Author(s):  
Thomas P. O’Connell ◽  
Marvin M. Chun ◽  
Gabriel Kreiman
Keyword(s):  
Neural Network ◽  
Visual Cortex ◽  
Neural Activity ◽  
Deep Neural Network ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Neural Decoding ◽  
Neural Responses ◽  
Prior Training ◽  
Single Category

AbstractDecoding information from neural responses in visual cortex demonstrates interpolation across repetitions or exemplars. Is it possible to decode novel categories from neural activity without any prior training on activity from those categories? We built zero-shot neural decoders by mapping responses from macaque inferior temporal cortex onto a deep neural network. The resulting models correctly interpreted responses to novel categories, even extrapolating from a single category.

Differences in Onset Latency of Macaque Inferotemporal Neural Responses to Primate and Non-Primate Faces

2005 ◽  
Vol 94 (2) ◽  
pp. 1587-1596 ◽  
Author(s):  
Roozbeh Kiani ◽  
Hossein Esteky ◽  
Keiji Tanaka
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Complex Object ◽  
Neural Responses ◽  
Onset Latency ◽  
Single Cell Responses ◽  
Response Onset ◽  
Stimulus Features ◽  
Animal Faces ◽  
Human Faces

Neurons in the visual system respond to different visual stimuli with different onset latencies. However, it has remained unknown which stimulus features, aside from stimulus contrast, determine the onset latencies of responses. To examine the possibility that response onset latencies carry information about complex object images, we recorded single-cell responses in the inferior temporal cortex of alert monkeys, while they viewed >1,000 object stimuli. Many cells responded to human and non-primate animal faces with comparable magnitudes but responded significantly more quickly to human faces than to non-primate animal faces. Differences in onset latency may be used to increase the coding capacity or enhance or suppress information about particular object groups by time-dependent modulation.

scholarly journals Novel objects with causal schemas elicit selective responses in tool- and hand-selective lateral occipito-temporal cortex

2021 ◽  
Author(s):  
Anna Leshinskaya ◽  
Mira Bajaj ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Essential Property ◽  
Neural Responses ◽  
Still Images ◽  
Event Sequences ◽  
Environmental Event ◽  
Parahippocampal Cortex ◽  
Novel Objects ◽  
Human Participants

Tool-selective lateral occipito-temporal cortex (LOTC) responds preferentially to images of tools (hammers, brushes) relative to non-tool objects (clocks, shoes). What drives these responses? Tools have elongated shapes and are more likely to have motor associations, but another essential property is that they exert causal effects on the environment. We tested whether LOTC would respond to novel objects associated with a tool-canonical schema in which their actions cause other events. To do so, we taught male and female human participants about novel objects embedded in animated event sequences, which varied in the temporal order of their events. Causer objects moved prior to the appearance of an environmental event (e.g., stars) while Reactor objects moved after an identical event; objects were matched on shape and motor association. During fMRI, participants viewed still images of these novel objects. We localized tool-selective LOTC and non-tool-selective parahippocampal cortex (PHC) by contrasting neural responses to images of familiar tools and non-tools. We found that LOTC responded more to Causers than Reactors; this effect was absent and weaker in right PHC. We also localized responses to images of hands, which elicit overlapping responses with tools. Across inferior temporal cortex, voxels’ tool and hand selectivity positively predicted a preferential response to Causers, and non-tool selectivity negatively so. We conclude that a causal schema typical of tools is sufficient to drive LOTC, and more generally, that preferential responses to domains across the temporal lobe may reflect the relational event structures typical of those domains.

[Q:] When Would You Prefer a SOSSAGE to a SAUSAGE? [A:] At about 100 msec. ERP Correlates of Orthographic Typicality and Lexicality in Written Word Recognition

2006 ◽  
Vol 18 (5) ◽  
pp. 818-832 ◽  
Author(s):  
O. Hauk ◽  
K Patterson ◽  
A. Woollams ◽  
L. Watling ◽  
F. Pulvermüller ◽  
...  
Keyword(s):  
Word Recognition ◽  
Current Source ◽  
Temporal Cortex ◽  
Event Related Potentials ◽  
Cortical Activation ◽  
Inferior Temporal Cortex ◽  
Decision Task ◽  
Early Form ◽  
Related Potentials ◽  
Typicality Effect

Using a speeded lexical decision task, event-related potentials (ERPs), and minimum norm current source estimates, we investigated early spatiotemporal aspects of cortical activation elicited by words and pseudowords that varied in their orthographic typicality, that is, in the frequency of their component letter pairs (bigrams) and triplets (trigrams). At around 100 msec after stimulus onset, the ERP pattern revealed a significant typicality effect, where words and pseudowords with atypical orthography (e.g., yacht, cacht) elicited stronger brain activation than items characterized by typical spelling patterns (cart, yart). At ~200 msec, the ERP pattern revealed a significant lexicality effect, with pseudowords eliciting stronger brain activity than words. The two main factors interacted significantly at around 160 msec, where words showed a typicality effect but pseudowords did not. The principal cortical sources of the effects of both typicality and lexicality were localized in the inferior temporal cortex. Around 160 msec, atypical words elicited the stronger source currents in the left anterior inferior temporal cortex, whereas the left perisylvian cortex was the site of greater activation to typical words. Our data support distinct but interactive processing stages in word recognition, with surface features of the stimulus being processed before the word as a meaningful lexical entry. The interaction of typicality and lexicality can be explained by integration of information from the early form-based system and lexicosemantic processes.

scholarly journals Behavioral demand modulates object category representation in the inferior temporal cortex

2014 ◽  
Vol 112 (10) ◽  
pp. 2628-2637 ◽  
Author(s):  
Nazli Emadi ◽  
Hossein Esteky
Keyword(s):  
Signal To Noise Ratio ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Object Categorization ◽  
Visual Object ◽  
Single Neurons ◽  
Neural Responses ◽  
Category Representation ◽  
Passive Fixation ◽  
Insight Into

Visual object categorization is a critical task in our daily life. Many studies have explored category representation in the inferior temporal (IT) cortex at the level of single neurons and population. However, it is not clear how behavioral demands modulate this category representation. Here, we recorded from the IT single neurons in monkeys performing two different tasks with identical visual stimuli: passive fixation and body/object categorization. We found that category selectivity of the IT neurons was improved in the categorization compared with the passive task where reward was not contingent on image category. The category improvement was the result of larger rate enhancement for the preferred category and smaller response variability for both preferred and nonpreferred categories. These specific modulations in the responses of IT category neurons enhanced signal-to-noise ratio of the neural responses to discriminate better between the preferred and nonpreferred categories. Our results provide new insight into the adaptable category representation in the IT cortex, which depends on behavioral demands.

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