Motivation and effort in individuals with social anhedonia

• Authors: Julie M. McCarthy, University of Maryland; Michael T. Treadway, Emory University; Jack J. Blanchard, University of Maryland
• Journal Title: Schizophrenia Research
• Volume: Volume 165, Number 1
• Publisher: Elsevier: 12 months | 2015-06-01, Pages 70-75
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.schres.2015.03.030
• Subjects: Health Sciences, Mental Health; Psychology, Clinical
• Keywords: Anhedonia; Effort; Motivation; Reward; Schizotypy; Adolescent; Adult; Analysis of Variance; Anhedonia; Decision Making; Female; Humans; Male; Motivation; Perceptual Disorders; Probability; Reward; Young Adult

Abstract

It has been proposed that anhedonia may, in part, reflect difficulties in reward processing and effortful decision making. The current study aimed to replicate previous findings of effortful decision making deficits associated with elevated anhedonia and expand upon these findings by investigating whether these decision making deficits are specific to elevated social anhedonia or are also associated with elevated positive schizotypy characteristics. The current study compared controls (n = 40) to individuals elevated on social anhedonia (n = 30), and individuals elevated on perceptual aberration/magical ideation (n = 30) on the Effort Expenditure for Rewards Task (EEfRT). Across groups, participants chose a higher proportion of hard tasks with increasing probability of reward and reward magnitude, demonstrating sensitivity to probability and reward values. Contrary to our expectations, when the probability of reward was most uncertain (50% probability), at low and medium reward values, the social anhedonia group demonstrated more effortful decision making than either individuals high in positive schizotypy or controls. The positive schizotypy group only differed from controls (making less effortful choices than controls) when reward probability was lowest (12%) and the magnitude of reward was the smallest. Our results suggest that social anhedonia is related to intact motivation and effort for monetary rewards, but that individuals with this characteristic display a unique and perhaps inefficient pattern of effort allocation when the probability of reward is most uncertain. Future research is needed to better understand effortful decision making and the processing of reward across a range of individual difference characteristics.