Effort, avolition and motivational experience in schizophrenia: Analysis of behavioral and neuroimaging data with relationships to daily motivational experience.

Abstract

Recent research suggests that schizophrenia is associated with reduced effort allocation. We examined willingness to expend effort, neural correlates of effort allocation, and the relationship of effort to daily motivational experience in schizophrenia. We recruited 28 individuals with schizophrenia and 30 controls to perform an effort task during fMRI. Individuals with schizophrenia also completed an ecological momentary assessment (EMA) protocol. Individuals with schizophrenia with high negative symptoms were less willing to expend effort for rewards. Daily EMA assessments of motivation were positively associated with effort allocation at a trend-level. Individuals with schizophrenia and controls displayed similar increases in BOLD activation in frontal, cingulate, parietal, and insular regions during effort-based decision-making. However, negative symptoms were associated with reduced BOLD activation in bilateral ventral striatum. These results replicate previous reports of reduced effort allocation in schizophrenia patients with severe negative symptoms, and provide evidence for the role of ventral striatum in effort impairments.