Date of Award
Spring 2020
Document Type
Honors Thesis
Department/Major
Chemistry
First Advisor
Dr. Lee Baugh
Second Advisor
Dr. Kelene Fercho
Third Advisor
Dr. Taylor Bosch
Keywords
intertemporal choice, fMRI, time perception, reward magnitude
Subject Categories
Medical Neurobiology
Abstract
In our day to day lives, the ability to make goal-oriented decisions plays a crucial role in both our work and social lives. Therefore, researchers have examined how factors such as a varying reward or delay may affect decision making. One’s performance when making intertemporal choices, decisions made between a smaller and sooner (SS) reward and a larger and later (LL) reward, are often examined to study these factors. Although time and reward magnitude are important dimensions when individuals make decisions during delay discounting, little is known about the relationship between time perception, reward magnitude, and underlying neural mechanisms. To address this gap in literature, participants completed a modified delay discounting task during fMRI with stimuli that included fluctuating reward and delay values. An exploratory factor analysis using behavioral data identified three categories of delays and reward values that were used to create brain contrasts. In these comparisons, the middle frontal gyrus and cingulate gyrus seemed to be more involved when choosing rewards of greater magnitude while the medial frontal gyrus and insula were found to be more active for longer delays. Our results suggest that delay and reward determination are handled by separate neural networks.
Recommended Citation
Mohr-Eymer, Conrad A., "Time for a Change? Brain Activity and Behavioral Performance Reveal Different Dynamics at Short, Intermediate, and Long Delay Intervals During a Delay Discounting Task" (2020). Honors Thesis. 111.
https://red.library.usd.edu/honors-thesis/111