The functional organization of control systems in human frontoparietal cortex
Abstract/Contents
- Abstract
- Human behavior is not reflexively yoked to the information that streams in from our senses. The way that we respond to a particular sensory stimulus might change from moment to moment depending on external rules, internal goals, and other factors that define the context for that behavior. This flexibility is often attributed to a cognitive control system in prefrontal cortex. Theoretical models propose that patterns of activity across prefrontal neurons convey a representation of abstract contextual information. This representation is thought to be the source of top-down control signals that influence processing in other neural circuits to determine how sensory information is interpreted and which responses are selected. In this thesis, I will report the results of three experiments that were designed to characterize the functional organization of control systems in the human brain. Subjects in my experiments performed context-dependent decision-making tasks, where they followed changing task rules to make simple decisions about the basic features of visual stimuli. I used functional magnetic resonance imaging to measure brain activity elicited by these tasks and determined the relative contributions of different brain regions with multivariate tools for decoding information from distributed activation patterns. My experiments identified a distributed network of regions in lateral prefrontal and parietal cortex that express strong representations of context during decision-making. I further determined that the strength of these representations varies over time, indicating that the engagement of control is dynamically allocated. My analyses show that the engagement of the frontoparietal control system can be understood to reflect a measure of prediction error relative to an internal model of the environmental statistics that determine the contextual relevance of different stimulus dimensions. Finally, I found that context is represented by the activity of fine-scaled intrinsic networks within prefrontal cortex. These results provide insight into the computational and neural mechanisms that confer cognitive flexibility on the human mind.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Waskom, Michael L |
|---|---|
| Associated with | Stanford University, Department of Psychology. |
| Primary advisor | Wagner, Anthony David |
| Thesis advisor | Wagner, Anthony David |
| Thesis advisor | Gardner, Justin, 1971- |
| Thesis advisor | Poldrack, Russell A |
| Advisor | Gardner, Justin, 1971- |
| Advisor | Poldrack, Russell A |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Michael L. Waskom. |
|---|---|
| Note | Submitted to the Department of Psychology. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Michael Lawrence Waskom
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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