Previous work has demonstrated that several aspects of visual processing are impaired in schizophrenia, including early perceptual processes and later higher-order processes. However, it remains unclear whether the stage of processing where early perception and later higher-order processes interact is impaired in schizophrenia. The current research examined this interface in schizophrenia using the attentional blink (AB) paradigm. We administered two rapid serial visual processing (RSVP) tasks to 143 patients with schizophrenia or schizoaffective disorder and 80 healthy controls: 1) a single target detection task, to measure basic visual perception; and 2) a dual target detection task, to measure the AB effect. In the dual target task, the two target stimuli (T1 and T2) were presented at varying positions or " lags" within a rapid sequential stream of distractor stimuli. Participants verbally identified the target stimuli. Both groups showed the expected AB effect, with T2 accuracy being poorest 200-500 ms after presentation of T1. However, patients showed an exaggerated AB effect compared to the healthy controls, with significantly reduced detection of T2, even after correcting for performance on the single target task. The reduction in accuracy was steeper and more pronounced in the patients during the AB lags, and it extended to lags before and after the typical AB. This performance pattern on the AB task suggests that patients with schizophrenia exhibit both deficits in visual processing at the interface of perceptual and attentional processing and a general attentional deficit. © 2011.
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