scholarly journals Differential rate of temporal processing across category-selective regions in human high-level visual cortex

2014 ◽  
Vol 14 (10) ◽  
pp. 187-187 ◽  
Author(s):  
A. Stigliani ◽  
K. S. Weiner ◽  
K. Grill-Spector
Keyword(s):  
Visual Cortex ◽  
Temporal Processing ◽  
Differential Rate ◽  
High Level

scholarly journals Temporal Processing Capacity in High-Level Visual Cortex Is Domain Specific

2015 ◽  
Vol 35 (36) ◽  
pp. 12412-12424 ◽  
Author(s):  
A. Stigliani ◽  
K. S. Weiner ◽  
K. Grill-Spector
Keyword(s):  
Visual Cortex ◽  
Temporal Processing ◽  
Processing Capacity ◽  
Domain Specific ◽  
High Level

scholarly journals Differential Sustained and Transient Temporal Processing Across Visual Streams

2018 ◽  
Author(s):  
Anthony Stigliani ◽  
Brianna Jeska ◽  
Kalanit Grill-Spector
Keyword(s):  
Visual Cortex ◽  
Temporal Processing ◽  
Visual Experience ◽  
Memory Trace ◽  
Temporal Cortex ◽  
Visual Input ◽  
Brain Responses ◽  
Neural Computations ◽  
High Level ◽  
Rapid Processing

ABSTRACTHow do high-level visual regions process the temporal aspects of our visual experience? While the temporal sensitivity of early visual cortex has been studied with fMRI in humans, temporal processing in high-level visual cortex is largely unknown. By modeling neural responses with millisecond precision in separate sustained and transient channels, and introducing a flexible encoding framework that captures differences in neural temporal integration time windows and response nonlinearities, we predict fMRI responses across visual cortex for stimuli ranging from 33 ms to 20 s. Using this innovative approach, we discovered that lateral category-selective regions respond to visual transients associated with stimulus onsets and offsets but not sustained visual information. Thus, lateral category-selective regions compute moment-tomoment visual transitions, but not stable features of the visual input. In contrast, ventral category-selective regions respond to both sustained and transient components of the visual input. Responses to sustained stimuli exhibit adaptation, whereas responses to transient stimuli are surprisingly larger for stimulus offsets than onsets. This large offset transient response may reflect a memory trace of the stimulus when it is no longer visible, whereas the onset transient response may reflect rapid processing of new items. Together, these findings reveal previously unconsidered, fundamental temporal mechanisms that distinguish visual streams in the human brain. Importantly, our results underscore the promise of modeling brain responses with millisecond precision to understand the underlying neural computations.AUTHOR SUMMARYHow does the brain encode the timing of our visual experience? Using functional magnetic resonance imaging (fMRI) and a temporal encoding model with millisecond resolution, we discovered that visual regions in the lateral and ventral processing streams fundamentally differ in their temporal processing of the visual input. Regions in lateral temporal cortex process visual transients associated with stimulus onsets and offsets but not the unchanging aspects of the visual input. That is, they compute moment-to-moment changes in the visual input. In contrast, regions in ventral temporal cortex process both stable and transient components, with the former exhibiting adaptation. Surprisingly, in these ventral regions responses to stimulus offsets were larger than onsets. We suggest that the former may reflect a memory trace of the stimulus, when it is no longer visible, and the latter may reflect rapid processing of new items at stimulus onset. Together, these findings (i) reveal a fundamental temporal mechanism that distinguishes visual streams and (ii) highlight both the importance and utility of modeling brain responses with millisecond precision to understand the temporal dynamics of neural computations in the human brain.

scholarly journals Organization of high-level visual cortex in human infants

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Ben Deen ◽  
Hilary Richardson ◽  
Daniel D. Dilks ◽  
Atsushi Takahashi ◽  
Boris Keil ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Human Infants ◽  
High Level

scholarly journals Visual search for object categories is predicted by the representational architecture of high-level visual cortex

2017 ◽  
Vol 117 (1) ◽  
pp. 388-402 ◽  
Author(s):  
Michael A. Cohen ◽  
George A. Alvarez ◽  
Ken Nakayama ◽  
Talia Konkle
Keyword(s):  
Visual Cortex ◽  
Visual Search ◽  
Visual System ◽  
Visual Processing ◽  
Search Task ◽  
Visual Search Task ◽  
Visual Object ◽  
Neural Responses ◽  
Object Categories ◽  
High Level

Visual search is a ubiquitous visual behavior, and efficient search is essential for survival. Different cognitive models have explained the speed and accuracy of search based either on the dynamics of attention or on similarity of item representations. Here, we examined the extent to which performance on a visual search task can be predicted from the stable representational architecture of the visual system, independent of attentional dynamics. Participants performed a visual search task with 28 conditions reflecting different pairs of categories (e.g., searching for a face among cars, body among hammers, etc.). The time it took participants to find the target item varied as a function of category combination. In a separate group of participants, we measured the neural responses to these object categories when items were presented in isolation. Using representational similarity analysis, we then examined whether the similarity of neural responses across different subdivisions of the visual system had the requisite structure needed to predict visual search performance. Overall, we found strong brain/behavior correlations across most of the higher-level visual system, including both the ventral and dorsal pathways when considering both macroscale sectors as well as smaller mesoscale regions. These results suggest that visual search for real-world object categories is well predicted by the stable, task-independent architecture of the visual system. NEW & NOTEWORTHY Here, we ask which neural regions have neural response patterns that correlate with behavioral performance in a visual processing task. We found that the representational structure across all of high-level visual cortex has the requisite structure to predict behavior. Furthermore, when directly comparing different neural regions, we found that they all had highly similar category-level representational structures. These results point to a ubiquitous and uniform representational structure in high-level visual cortex underlying visual object processing.

scholarly journals Atypical topography of high-level visual cortex is associated with reading difficulty

2019 ◽  
Vol 19 (10) ◽  
pp. 34a
Author(s):  
Emily Kubota ◽  
Jason D Yeatman
Keyword(s):  
Visual Cortex ◽  
Reading Difficulty ◽  
High Level

scholarly journals Eccentricity drives developmental organization of human high-level visual cortex

2018 ◽  
Vol 18 (10) ◽  
pp. 1149
Author(s):  
Jesse Gomez ◽  
Michael Barnett ◽  
Kalanit Grill-Spector
Keyword(s):  
Visual Cortex ◽  
High Level

scholarly journals Rats spontaneously perceive global motion direction of drifting plaids

2021 ◽  
Author(s):  
Giulio Matteucci ◽  
Benedetta Zattera ◽  
Rosilari Bellacosa Marotti ◽  
Davide Zoccolan
Keyword(s):  
Visual Cortex ◽  
Perceived Similarity ◽  
Global Motion ◽  
Motion Direction ◽  
Visual Objects ◽  
Visual Priming ◽  
Priming Paradigm ◽  
High Level ◽  
Mouse Visual Cortex ◽  
Motion Detectors

AbstractComputing global motion direction of extended visual objects is a hallmark of primate high-level vision. Although neurons selective for global motion have also been found in mouse visual cortex, it remains unknown whether rodents can combine multiple motion signals into global, integrated percepts. To address this question, we trained two groups of rats to discriminate either gratings (G group) or plaids (i.e., superpositions of gratings with different orientations; P group) drifting horizontally along opposite directions. After the animals learned the task, we applied a visual priming paradigm, where presentation of the target stimulus was preceded by the brief presentation of either a grating or a plaid. The extent to which rat responses to the targets were biased by such prime stimuli provided a measure of the spontaneous, perceived similarity between primes and targets. We found that gratings and plaids, when uses as primes, were equally effective at biasing the perception of plaid direction for the rats of the P group. Conversely, for G group, only the gratings acted as effective prime stimuli, while the plaids failed to alter the perception of grating direction. To interpret these observations, we simulated a decision neuron reading out the representations of gratings and plaids, as conveyed by populations of either component or pattern cells (i.e., local or global motion detectors). We concluded that the findings for the P group are highly consistent with the existence of a population of pattern cells, playing a functional role similar to that demonstrated in primates. We also explored different scenarios that could explain the failure of the plaid stimuli to elicit a sizable priming magnitude for the G group. These simulations yielded testable predictions about the properties of motion representations in rodent visual cortex at the single-cell and circuitry level, thus paving the way to future neurophysiology experiments.

scholarly journals The Effect of High-Level Illumination on Brain Activity in the Human Visual Cortex

2014 ◽  
Vol 98 (2) ◽  
pp. 87-91
Author(s):  
Yasuhiro Kawashima ◽  
Hiroyuki Yamashiro ◽  
Hiroki Yamamoto ◽  
Tomokazu Murase ◽  
Yoshikatsu Ichimura ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Brain Activity ◽  
Human Visual Cortex ◽  
High Level
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