Reward anticipation and trait anhedonia: An electrophysiological investigation in subjects with schizophrenia

OBJECTIVE: Investigate impairment of reward anticipation in subjects with schizophrenia (SCZ) and its association with negative symptom dimensions and hedonic experience. METHODS: Event-related potentials (ERPs) were recorded, in thirty SCZ and twenty-three matched healthy controls (HC), during a "Monetary Incentive Delay" task in which reward and loss cues (incentive cues of positive and negative value) of different magnitude, as well as neutral cues were presented. ASSESSMENTS: anticipatory and consummatory pleasure, trait anhedonia and motivation in all subjects; avolition and expressive deficit in SCZ. RESULTS: SCZ had lower motivation but comparable hedonic experience with respect to HC. In HC, during reward anticipation, the early P3 was larger for large magnitude incentives, irrespective of their valence, while the late P3 was larger for large reward. In SCZ, early P3 did not discriminate the incentive magnitude and the late P3 was larger for large loss. Early P3 amplitude for large magnitude incentives was inversely related to trait social anhedonia but not to negative symptoms dimensions. CONCLUSIONS: SCZ are unable to integrate the incentive magnitude and reward value of future events in the context of their ongoing task. P3 abnormalities are associated with trait anhedonia, but not with negative symptoms dimensions. SIGNIFICANCE: In line with recent studies, our findings indicate that anhedonia and avolition are partially independent constructs.