Elucidating the temporal dynamics of human visual cortex
Abstract/Contents
- Abstract
- The world around us is constantly changing and in many more ways than we can see. As visual stimuli bombard us at different rates, some changes occur on timescales that are too fast or slow to detect with the naked eye. However, the human visual system is able to perceive a broad enough range of temporal dynamics to distinguish stable aspects of the environment from rapidly changing ones and operate on them in real time. While this may seem effortless, the neural mechanisms that give rise to this fundamental perceptual ability are largely unknown. In the three experiments described here, we use functional magnetic resonance imaging (fMRI) and computational techniques to model how neurons in the visual system code changes to the appearance of the world over time. First, we examine how the transient and sustained aspects of a stimulus are processed in the visual system focusing on regions in early visual cortex in Study 1 and regions in high-level visual cortex in Study 2. Both studies reveal differential response dynamics between ventral temporal cortex (VTC) and lateral temporal cortex (LTC). That is, we find that brain regions in VTC receive contributions from both sustained and transient channels, whereas regions in LTC are dominated by contributions from the transient channel. In Study 3, we test whether the distinct temporal dynamics observed across domain-specific regions in Study 2 have behavioral consequences. Contrary to prevailing theories, we find that different regions have different processing capacities, which have behavioral implications. Specifically, character-selective regions have the lowest capacity, face- and place-selective regions have an intermediate capacity, and body-selective regions have the highest capacity. Together, these results suggest that temporal processing capacity is a characteristic of synchronized domain-specific networks in high-level visual cortex and contributes to the segregation of cortical regions.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2018 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Stigliani, Anthony William Michael |
|---|---|
| Associated with | Stanford University, Department of Psychology. |
| Primary advisor | Grill-Spector, Kalanit |
| Thesis advisor | Grill-Spector, Kalanit |
| Thesis advisor | Gardner, Justin, 1971- |
| Thesis advisor | Norcia, Anthony Matthew |
| Advisor | Gardner, Justin, 1971- |
| Advisor | Norcia, Anthony Matthew |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Anthony William Michael Stigliani. |
|---|---|
| Note | Submitted to the Department of Psychology. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2018. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2018 by Anthony William Michael Stigliani
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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