Montez, David
(2017)
BRAIN SYSTEM MECHANISMS UNDERLYING DEVELOPMENTAL CHANGES IN WORKING MEMORY PERFORMANCE DURING ADOLESCENCE.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
BRAIN SYSTEM MECHANISMS UNDERLYING DEVELOPMENTAL CHANGES IN WORKING MEMORY PEFORMANCE DURING ADOLESCENCE
David F. Montez, Ph.D.
University of Pittsburgh, 2016
Working memory is a critical component of executive function that continues to develop during adolescence. In addition to developmental improvements in mean performance, there are significant decreases in behavioral variability. The neural underpinnings of developmental changes in behavioral variability are poorly understood although they would provide important insight into the nature of improvements in working memory. This dissertation takes a multilevel approach, applying whole-brain fMRI analyses and computational modeling to a longitudinal data set acquired from a cohort of 8-30 year olds as they performed a memory guided saccade task.
First, we delineate behavioral changes in trial-to-trial in performance variability and explore these changes within a drift diffusion framework. We find that a trial-to-trial variations in gain and response thresholds accounts for features of behavioral instability. Second, we establish that trial-to-trial behavioral variability is associated with fluctuations in the expression of whole brain patterns of task-related BOLD signal, or brain state variability, which is a predicted consequence of widespread gain modulation. We find that individual trajectories of developmentally stabilizing behavior are predicted by changes in brain state variability. Third, in order to explore reports of a relationship between the complexity of neural activity and behavioral stability, we characterize developmental increases in BOLD complexity in a task context and assess their relationship to developmental changes in behavior. Collectively, our findings provide novel evidence that the age-related stabilization of behavioral performance is driven by the stabilization of widespread gain signals across development.
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| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
27 February 2017 |
| Date Type: |
Publication |
| Defense Date: |
28 November 2016 |
| Approval Date: |
27 February 2017 |
| Submission Date: |
2 December 2016 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
109 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Medicine > Neurobiology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
adolescence brain state development working memory |
| Date Deposited: |
27 Feb 2017 18:41 |
| Last Modified: |
28 Feb 2017 06:15 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/30655 |
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BRAIN SYSTEM MECHANISMS UNDERLYING DEVELOPMENTAL CHANGES IN WORKING MEMORY PERFORMANCE DURING ADOLESCENCE. (deposited 27 Feb 2017 18:41)
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