Graduation Year

2019

Document Type

Dissertation

Degree

Ph.D.

Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Psychology

Major Professor

Geoffrey F. Potts, Ph.D.

Committee Member

Toru Shimizu, Ph.D.

Committee Member

Chad Dube, Ph.D.

Committee Member

David Drobes, Ph.D.

Committee Member

Nathan Maxfield, Ph.D.

Keywords

reward, punishment, feedback-related negativity, reward positivity, risk-taking behavior

Abstract

Optimal decision-making entails outcome evaluation, comparing received costs and benefits with predicted costs and benefits. The anterior cingulate cortex (ACC), a brain area with major connections to the appetitive and aversive motivation systems, may provide the neural substrate of this evaluation process. One way to measure the relative contribution of these systems on decision-making is to measure individual differences in risk-taking behaviors. For individuals who make risky choices, this evaluation step may be biased: some show a preference for immediate, short-term rewards (increased appetitive system), while devaluing the long-term consequences of their choices (decreased aversive system). However, most studies supporting this theory have utilized monetary loss as the punishment. Other punishments that represent the presence of an aversive outcome, such as delivery of a painful stimulus, may be processed in a separate brain area and thus, may have differing effects on decision-making. The current study aimed to answer two main questions. First, we asked: is the ACC engaged by both appetitive stimuli and aversive stimuli? To answer this question, we recorded the Feedback-Related Negativity (FRN) response, a component thought to represent activity of the ACC, during a passive reward and punishment prediction task. Results indicated that the FRN responded to whether the outcome was A) unexpected and B) delivered or withheld, but not to the valence of the outcome. Second, we asked: do individual differences in these two systems have a differential impact on decision-making? To answer this question, participants completed a gambling task where they had to choose between large and small bets based on a probability of winning while we recorded their FRN response. They also completed self-report questionnaires indicating their sensitivity to reward/punishment and risk-taking behaviors. Results indicated that increased sensitivity of the appetitive system and decreased sensitivity of the aversive system (measured by both self-report and ERPs) predicted risky choice on the self-report measure and less so on the behavioral measure. Taken together, these results complement those that suggest the ACC is involved in evaluating both costs and benefits and may be influenced by both appetitive and aversive motivational systems.

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