Remitted schizophrenia-spectrum patients with spared working memory show information processing abnormalities

Working memory and information processing abnormalities are often reported in schizophrenia. The aim of this study was to examine visual backward mask ing (BM) functions in remitted schizophrenia-spectrum patients with spared working memory functions. Seventy-two patients with DSM-IV schizophrenia-sp ectrum disorders were screened using the Wisconsin Card Sorting Test (WCST) and the digit span forward/backward tasks. Patients with spared WCST and d igit span performances were selected and administered a spatial working mem ory test and two BM procedures (target identification and location). The sc hizophrenia-spectrum group with spared WCST and digit span performances inc luded individuals with schizophreniform disorder (N=11), schizophrenia (N=2 ), and schizoaffective disorder (N=2). These patients were clinically remit ted and demonstrated spared IQ, normal spatial working memory, and relative ly high psychosocial functioning. However, there was a significant impairme nt in the BM procedure, most prominently in the target location task and at short interstimulus intervals. These results suggest that the BM dysfuncti on is a trait marker of schizophrenia-spectrum disorders and may be present in the absence of working memory abnormalities.