FriSem

Gustavo Santiago-Reyes, PhD student in Bioengineering, working with Professor Russell Poldrack, Chair Department of Psychology and Associate Professor Todd Coleman, Department of Bioengineering

Title: Decisions under Risk and Autonomic Arousal

Abstract:  We make decisions under risk every day, weighing potential gains against possible losses to choose among different options. The subjective value of a decision is context-dependent and is also linked to the arousal system. Here, we ask whether arousal responses also vary with decision context. To investigate this, we repurpose the NARPS dataset (Botvinik-Nezer et al., 2019), which includes pupil dilation measurements from participants performing a mixed gambles task. A key manipulation in the task alters the decision context by varying the range of possible gains and losses across two conditions. Our findings suggest that increased tonic arousal consistently speeds decision-making, as evidenced by decreased response times, regardless of context. Additionally, while phasic arousal increases in response to uncertainty and effort across conditions, it encodes subjective values in a context-dependent manner. These results highlight the interaction between the valuation network and the arousal system in value representation, as well as the context-independent role of arousal in uncertainty, effort, and decision speed.