Context binding in schizophrenia: effects of clinical symptomatology and item content

Impairments in source monitoring have been widely reported in schizophrenia, with patients typically misattributing self-generated items to external sources. Some studies have reported that patients with more severe positive symptoms (notably hallucinations) exhibit a greater impairment on these tasks, although findings are not uniformly positive. The emotional content of the items to be remembered also may affect subsequent retrieval, with some studies suggesting a greater misattribution bias for affectively-laden material. Recently, it has been proposed that schizophrenic patients have a fundamental deficit in binding different contextual elements together in memory. The effect of clinical symptomatology and item content on source monitoring and context binding has yet to be examined in a single study. Twenty-one patients with schizophrenia and 21 healthy control subjects completed a task wherein memory for affective and neutral word pairs was assessed in conjunction with memory for both source and temporal information. Schizophrenic patients performed more poorly than controls overall, and tended to exhibit a more fractionated retrieval of word pairs across all levels of affective valence. Current intellectual level and overall verbal memory performance were significantly correlated with context binding performance for positive and neutral word pairs. Clinical symptomatology was unrelated to source monitoring performance. The results of this pilot study provide tentative support for the notion that schizophrenia is associated with an impairment in combining contextual cues together to form a coherent memory of an event, irrespective of the affective valence of the material. Clinical symptomatology bore no significant relationship to source memory performance.