Name: Elyse Carlson

Dissertation Defense Meeting
Date: Thursday, November 25, 2025
Time: 11am Eastern Time

Location: CABI Conference Room, 831 Marietta St. NW, Atlanta GA 

Virtual: https://gatech.zoom.us/j/98325914948

Dissertation Chair/Advisor:
Mark Wheeler, Ph.D. (Georgia Institute of Technology)
 
Dissertation Committee Members:

Anna Ivanova, Ph.D. (Georgia Institute of Technology)

Scott Moffat, Ph.D. (Georgia Institute of Technology)

Sashank Varma, Ph.D. (Georgia Institute of Technology)

Kristine Wilckens, Ph.D. (University of Pittsburgh)

Title: Is There Evidence for a Neural Accumulation to Boundary Mechanism in Associative Memory Retrieval?

Abstract:

Memory search is the process of identifying target information and its associated context during memory retrieval. During memory search, the brain makes decisions about the relevance of available information which is accessible in the memory search space. Thus, the memory search process can be thought of in the context of an accumulation-to-boundary framework wherein the brain searches for evidence in favor of one choice over other alternatives. When enough information has been amassed, a decision is made, and the memory retrieved. While accumulation-like effects of memory retrieval have been modelled behaviorally, there is a lack of research examining whether this effect is also observed in functional magnetic resonance imaging (fMRI) paradigms. The goal of this research was to begin to elucidate this unresolved question by using fMRI to measure changes in the temporal dynamics of the blood oxygen level dependent (BOLD) response in healthy younger (21 – 35 years) adults during a paired-associates memory retrieval task. BOLD timeseries data of memory retrieval partially replicated previous work using perceptual decision-making paradigms. Additionally, overlapping regions of interest (ROIs) between perception and memory retrieval suggest that participants were recruiting perceptual regions to reinstate visual information from previously encoded images. This study contributes to existing research by demonstrating that perceptual- and memory-based decision-making engage similar, yet partially distinct neural mechanisms, while providing novel insights into the temporal dynamics of memory search and retrieval.