A hallmark of negative symptoms in schizophrenia is reduced motivation and

A hallmark of negative symptoms in schizophrenia is reduced motivation and goal directed behavior. differ in the overall amount of effort expenditure but patients made significantly less optimal choices in terms of maximizing rewards. These results provide further evidence for a selective deficit in the ability of schizophrenia patients to utilize environmental cues to guide reward-seeking behavior. INTRODUCTION A growing body of evidence suggests that reduced motivation and goal-directed behavior may occur in schizophrenia without concomitant alterations of hedonic responsivity (Barch and Dowd 2010 Folley and Park 2010 Gard et al. 2007 Gold et al. 2008 In preclinical models effort-based decision-making paradigms that assess the willingness to invest greater effort in order to obtain larger or desired rewards have repeatedly implicated disruption of corticostriatal dopamine (DA) as a possible substrate for motivational impairments (Salamone and Correa 2012 Treadway and Zald 2013 indeed potentiation or attenuation of DA signaling can increase or decrease effort expenditure for rewards in both rodents (Bardgett et al. 2009 Floresco et al. 2008 Salamone et al. 2007 and humans (Venugopalan et al. 2011 Wardle et al. 2011 In the context of schizophrenia however it appears unlikely that bad symptoms are mediated by a global reduction in striatal DA given robust evidence for striatal DA elevations like a mechanism underlying symptoms of psychosis (Fusar-Poli and Meyer-Lindenberg 2012 Howes et al. 2013 An alternative explanation is definitely that both positive and negative symptoms results from irregular (as opposed to simply enhanced or reduced) striatal DA launch that may fail to CGS-15943 appropriately respond to meaningful incentive incentives. Consistent with this CGS-15943 model several recent studies of effort-based decision-making in individuals with schizophrenia have found no evidence for a global reduction of effort expenditure but rather an apparent failure to mobilize effort in response to maximally rewarding cues (Barch et al. 2014 Fervaha et al. 2013 Platinum et al. 2013 In the present study we used a similar strategy in an attempt to replicate these prior findings and lengthen them with a more direct investigation into the utilization of incentive magnitude and probability info in guiding effort-based choice in schizophrenia individuals. METHODS Participants and Process All subjects offered written educated consent and all study procedures were authorized by the Vanderbilt Institutional Review Table. 13 outpatients with schizophrenia (SZ) participated in the study and data from 15 CGS-15943 healthy control subjects (HC) were drawn from a prior published study (Treadway et al. 2012 All individuals were recruited from private-care facilities in Nashville TN and completed the Organized Clinical Interview for DSM-IV (First et al. 2005 to confirm diagnosis. Exclusion criteria for the SZ were: IQ lower than 85 a prior history of head stress/neurological disorder or a history of drug use in the previous year. The severity of symptoms was evaluated with SANS and SAPS interviews (Andreasen 1984 b; Zigler and Levine 1981 Subjects were then instructed to total the Effort-Expenditure for Rewards Task (EEfRT). One individual failed to comply with task instructions and was excluded from the study. A summary of demographics and sign scores are reported in Table 1. The two organizations differed in years of education which was included like a covariate in subsequent group analyses. However note that SZ experienced undamaged IQ (mean =100; S.D. = 10.4). Table 1 Demographic characteristics is definitely a computerized effort-based decision-making task (Treadway et al. 2009 (Fig 1). On each trial the participant must select between a high effort option and a low effort option which require varying amounts of speeded manual switch pressing. For low-effort choices participants LUCT are eligible to win $1.00 while eligible amounts for selecting the high effort option ranged between $1.24 – $4.30 (“incentive magnitude”). Additionally probability of incentive receipt (no matter choice) assorted across trials. Participants were provided with accurate probability CGS-15943 cues at the beginning CGS-15943 of each trial indicating that they had a “high” (88%) “medium” (50%) or “low” (12%) probability of receiving money for the choice made on that trial. The.