The use of cognitive context in schizophrenia: an investigation

Background. Cognitive deficits in schizophrenia have recently been ascribed to impaired representation and use of cognitive context. Context is define d as relevant information held temporarily in mind to mediate appropriate b ut often non-habitual responses. Methods. Parallel studies in a variety of cognitive domains were designed i n order to explore the generality of any schizophrenic deficit in context u se. In all of the tasks (a Stroop task, a Continuous Performance Task and a cued spatial location task), we examined how performance was affected by t he time for which contextual information must be held in mind, and by wheth er context or task demands were consistent or varying between trials. It wa s predicted that manipulation of these variables would produce tests especi ally sensitive to schizophrenic attentional problems. Results. Predictions were partially confirmed. Although increasing contextu al demands failed in most cases to produce disproportionate slowing of perf ormance in patients, error data were largely in line with predictions. At t he same time, the data did not suggest a simple unitary context deficit. In stead, different aspects of context - the time over which contextual inform ation must be held in mind and the consistency of context - were differenti ally important in different tasks. Conclusions. The cognitive impairments of schizophrenic patients cannot be simply characterized as a generalized context deficit. A more differentiate d, if not task specific, picture of schizophrenic deficits is suggested.