Psychophysiological and Behavioral Evidence of Deficits in Sensitivity to Reward Magnitude in Substance Use Disorders

Individuals with substance use disorders often show impaired sensitivity to reward value. However, it is not clear whether such impairment impacts reward-related decision making and whether it can be quantified objectively via brain imaging modalities. This talk presents results from two studies: the first study employed reinforcement learning modeling to show that individuals with frequent alcohol use show impaired value-based modulation between computationally cheaper model-free (habitual) control and costly model-based (goal-directed) control in reward-related decision making, which in turn is associated with risk-taking behavior and anhedonia. The second study used electroencephalography (EEG) to objectively quantify reduced sensitivity to monetary value in individuals with chronic cocaine use, such that the EEG-derived signal(i.e., P300 amplitude) that is sensitive to reward value did not differentiate between high and low money reward in cocaine users, as it did in non-cocaine using controls.

Learning Objectives: 

1. Review reward sensitivity in substance use disorders.

2. Examine deficits in reward related decision making in frequent alcohol users, via computational modeling of task behavior.

3. Discuss impaired sensitivity to reward value using EEG in chronic cocaine users.