Name: Jenny Walker
Ph.D. Dissertation Proposal Meeting
Date: Friday April 21, 2023
Time: 2:15pm EST
Location: click here
Advisor: Mark Wheeler, Ph.D. (Georgia Tech)
Dissertation Committee Members:
Thackery Brown, Ph.D. (Georgia Tech)
Madeleine Hackney, Ph.D. (Emory University)
Hsiao-Wen Liao, Ph.D. (Georgia Tech)
Rick Thomas, Ph.D. (Georgia Tech)
Title: How does a current perceptual decision-making model carry forward to older adult samples? A comparative & hierarchal exploration of BOLD signal timecourses.
Abstract: Perceptual decision-making (PDM) occurs when incoming sensory information is used to make a choice amongst an array of options. PDM is likewise foundational to everyday functioning across a variety of contexts, making it an important and popular area of cognitive research. One approach is to view the process as a series of three steps: 1) intake and processing of sensory stimuli from the environment, 2) amassing of evidence towards or away from opposing choices, and 3) finalizing one’s choice selection. This framework is conceptually supported by an extensive body of human and non-human primate literature that spans several decades. One critical example is a series of findings that suggest these stages are discernable at the neural level because each is associated with specific brain regions. This conclusion is based on a complex review of younger adult BOLD timecourse profiles collected via functional magnetic resonance imaging during an object identification PDM task. However, despite this useful insight, it is unclear if or how the same results will hold for older adult brains that are likely experiencing numerous age-related functional and structural changes, particularly cortical/hemispheric dedifferentiation and global age-related changes to the central nervous system. This lack of understanding makes the results of PDM aging experiments difficult to interpret from a hierarchal perspective. The goal of the current work is to address that lingering uncertainty. This will be accomplished by comparing the physical and temporal properties of older and younger adults’ BOLD timeseries data on a stage-by-stage basis, hierarchal clustering, and an exploratory dedifferentiation analysis.