MS Defense by Jenny Walker

Event Details
  • Date/Time:
    • Friday April 9, 2021
      12:30 pm - 2:30 pm
  • Location: Atlanta, GA; REMOTE
  • Phone:
  • URL: Bluejeans
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Summary Sentence: The Impact of Criterion Shifts on Evidence Accumulation in the Inferior Temporal Cortex

Full Summary: No summary paragraph submitted.

Name: Jenny Walker

Master’s Thesis Defense Meeting

Date: Friday, April 9, 2021

Time: 12:30pm



Advisor: Mark Wheeler, Ph.D. (Georgia Tech)


Thesis Committee Members:

Mark Wheeler, Ph.D. (Georgia Tech)

Audrey Duarte, Ph.D. (Georgia Tech)

Chris Hertzog, Ph.D. (Georgia Tech)


Title: The Impact of Criterion Shifts on Evidence Accumulation in the Inferior Temporal Cortex


Abstract: Decision-making is a cognitive process that occurs in stages and can be conceptualized by variations of sequential sampling models which suggest that, for the options in a binary forced-choice decision-making task, there are opposing thresholds that the amount of evidence accumulated must cross before a selection is made (Ratcliff, 1978; Ratcliff & McKoon, 2008). That process is often influenced by prior knowledge that has the potential to bias an individual towards or away from given options, thereby changing the amount of associated sensory evidence processed over time (Dunovan & Wheeler, 2018). Meaning, when a criterion shift (prior knowledge) biases an individual toward the correct choice (a valid trial), younger adults have a propensity to take less time to respond, be more accurate in their responses, and show decreased BOLD activity in the inferior temporal cortex (ITC). Alternatively, the option biased against (an invalid trial) will take more time, produce poorer accuracy scores, and is associated with increased BOLD activity in the ITC. However, little is known about how well such results carry across the lifespan because current literature focuses mostly on younger adults. Older adults have a propensity to take their time during decision-making tasks and perform well, and it is believed they do so by behaving inflexibly when presented with prior knowledge. Younger adults are more likely to incorporate informative cues, while older adults tend to disregard them in favor of taking their time (Starns & Ratcliff, 2010). This fMRI work aimed to examine these conclusions from a lifespan perspective using a Posner-like cued face/house discrimination task. Special attention was paid to controlling for age-related sensory confounds. Contrary to the hypothesis that only younger adults would incorporate cues into their decision-making process, both age groups performed similarly and responded faster/more accurately for valid trials relative to invalid trials. However, the underlying trends in the ITC BOLD data were not consistent across age groups, suggesting that there are different neural mechanisms underlying the same behavioral outcomes as a function of age.

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ms defense
  • Created By: Tatianna Richardson
  • Workflow Status: Published
  • Created On: Apr 9, 2021 - 12:40pm
  • Last Updated: Apr 9, 2021 - 12:40pm