Type
Text
Type
Dissertation
Advisor
Leung, Hoi-Chung | Anderson, Brenda | Mohanty, Aprajita | Li, Chiang-Shan Ray.
Date
2016-12-01
Keywords
fMRI, functional connectivity, thalamus, working memory | Neurosciences -- Cognitive psychology
Department
Department of Biopsychology
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77005
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Visual working memory refers to the temporary maintenance and manipulation of information to achieve a goal and is thought to involve a network of frontal, parietal and visual regions. Accumulating evidence suggests that the thalamus is also involved in visual attention and working memory. The thalamus shows extensive neuroanatomical connectivity with cortical regions involved in working memory and is hypothesized to play an important role in the synchronization of task dependent activity among cortical networks. However, work on functional connectivity between the thalamus and cortex during visual and visuo-spatial working memory in humans is sparse. The studies reported here applied functional magnetic resonance imaging in humans to investigate (1) functional connectivity between thalamus and cortical regions involved in visual working memory and (2) the association between thalamocortical connectivity with neural representation of memorized visual stimuli, and with behavioral performance. Study 1 investigated thalamocortical connectivity during selective maintenance of face and scene stimuli. We showed that thalamocortical connectivity varies in accordance with the relevance of the to-be-remembered visual category; connectivity between the thalamus and category selective visual regions are greater when a region’s preferred stimulus category is relevant, compared to when it is irrelevant to task goals. Further, stronger functional connectivity between the thalamus and the fusiform face area (FFA) was associated with greater behavioral advantage of selectively maintaining face stimuli over maintaining both face and scene stimuli. Study 2 investigated whether variation in thalamocortical connectivity while maintaining visual stimuli is associated with subsequent visual search performance. We showed that different search performance measures are differentially associated with thalamocortical and cortico-cortical connectivity. We found no clear relationship between thalamocortical connectivity and representation in visual working memory. Together, these findings suggest that, along with the better studied cortico-cortical connectivity, thalamocortical connectivity is an important component of the visual working memory system and is associated with behavior. | Visual working memory refers to the temporary maintenance and manipulation of information to achieve a goal and is thought to involve a network of frontal, parietal and visual regions. Accumulating evidence suggests that the thalamus is also involved in visual attention and working memory. The thalamus shows extensive neuroanatomical connectivity with cortical regions involved in working memory and is hypothesized to play an important role in the synchronization of task dependent activity among cortical networks. However, work on functional connectivity between the thalamus and cortex during visual and visuo-spatial working memory in humans is sparse. The studies reported here applied functional magnetic resonance imaging in humans to investigate (1) functional connectivity between thalamus and cortical regions involved in visual working memory and (2) the association between thalamocortical connectivity with neural representation of memorized visual stimuli, and with behavioral performance. Study 1 investigated thalamocortical connectivity during selective maintenance of face and scene stimuli. We showed that thalamocortical connectivity varies in accordance with the relevance of the to-be-remembered visual category; connectivity between the thalamus and category selective visual regions are greater when a region’s preferred stimulus category is relevant, compared to when it is irrelevant to task goals. Further, stronger functional connectivity between the thalamus and the fusiform face area (FFA) was associated with greater behavioral advantage of selectively maintaining face stimuli over maintaining both face and scene stimuli. Study 2 investigated whether variation in thalamocortical connectivity while maintaining visual stimuli is associated with subsequent visual search performance. We showed that different search performance measures are differentially associated with thalamocortical and cortico-cortical connectivity. We found no clear relationship between thalamocortical connectivity and representation in visual working memory. Together, these findings suggest that, along with the better studied cortico-cortical connectivity, thalamocortical connectivity is an important component of the visual working memory system and is associated with behavior. | 110 pages
Recommended Citation
Huang, Anna Song, "Functional Connectivity of Thalamocortical Networks in Visual Working Memory" (2016). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2867.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2867