Hedonic and Motivational Influences on the Reward Positivity

Lindsay S. Shaffer

Advisor: Craig McDonald, PhD, Department of Psychology

Committee Members: Tyler H. Shaw, William Kennedy

Online Location, Online
July 29, 2025, 12:00 PM to 02:00 PM

Abstract:

Successful behavioral adaptation requires an ongoing assessment of outcomes based on one’s current state. A frontocentral event-related potential (ERP) associated with reward feedback, the reward positivity (RewP), has been linked to reflect feedback pertaining to goal attainment. One assumption is that updates in information relevant for goal attainment should modulate the RewP. Although subjective reward preferences and motivational states influence the RewP, I investigate across three Aims whether changes in reward preference as a function of motivational state modulate the RewP. To examine this, participants completed two rounds of a modified Doors Task incorporating Pavlovian conditioning during electroencephalography (EEG) recordings and obtained feedback associated with food reinforcers equally matched in pleasantness and desirability. Participants in between rounds underwent reinforcer devaluation, a paradigm designed to isolate inference-based behavior based on decreasing reward value, by eating one of the foods to satiety. I did not find differences in RewP amplitudes after reinforcer devaluation despite changes in goal-directed behavior (Aim 1). My null RewP results could not be explained by differences in the probabilistic presentation (Aim 2) or informational content of feedback (Aim 3). Together, all Aims suggest that while the RewP is sensitive to reward feedback and contextually sensitive to task demands, factors pertinent to goal attainment might provide different contributions toward the RewP if goal-based value updating required inference.