The Relationship of Visual Backward Masking Performance with Positive and Negative Symptoms in Patients with Schizophrenia

The goal of the current study was to investigate the relationship of Visual Backward Masking performance with positive and negative symptoms in patients with schizophrenia. To do so, 32 schizophrenic patients (15 acute patients and 17 chronic patients), and 32 normal individuals, all ranging from 19 to 51 years were chosen. The two groups were matched for age, sex and education level and were assessed by the Visual Backward Masking Task. Moreover, in order to study the multivariate correlation between positive and negative symptoms of schizophrenia with Visual Backward Masking performance on schizophrenic patients, the Scale for Assessment of Negative Symptoms (SANS) and the Scale for Assessment of Positive Symptoms (SAPS) were both carried out. Results indicated that schizophrenic patients had significantly poorer performance in comparison to normal individuals in the entire Interstimulus Intervals (ISI) (20, 40, 60, 80, & 100 Milliseconds) of the Visual Backward Masking Task and no mask condition. Regression analysis showed that among positive symptoms, Formal thought disorder component was a negative and significant predictor of Visual Backward Masking performance; and among negative symptoms, attention deficit, the affective flattening and the volition - apathy components were negative and significant predictors of visual backward masking performance.