Impaired Continuous Performance Test and the Go/ NoGo Task, but Intact Context Sensitivity, in Patients with Schizophrenia

Difficulty inhibiting context-inappropriate behavior is a common deficit in psychotic disorders. Schizophrenia (SZ) is associated with impaired response inhibition. In SZ, deficit in context processing was suggested as a critical mechanism for impaired response inhibition during the performance, but results of studies are equivocal. In the present study, we investigated the context processing during a switch from Continuous Performance Task (CPT) to Go/NoGo task in patients with SZ. A cross-sectional design was used in order to allow analysis of the means between SZ patients and Healthy Controls subjects (HC). SZ patients (n=180) were compared with HC (n=112) on their performance on CPT and Go/NoGo task as well as during the switch from CPT and Go/NoGo task. Reaction time, variability of reaction time, and accuracy measures were significantly impaired on both CPT and Go/NoGo task in SZ compared to HC. Patients with SZ revealed significantly more impairment on response inhibition performance than HC. However, although SZ patients show impaired response inhibition performance on CPT-Go/NoGo tasks, requiring a different response rate, their ability to create response bias did not differ from HC. Our findings suggest that context sensitivity is intact in SZ patients during the switch from CPT to Go/NoGo task paradigm. Keywords: