Behavioural studies of spatial working memory dysfunction in schizophrenia: a quantitative literature review

Cognitive impairments in schizophrenia have been recognized as a prominent feature of the illness. Research is now focusing on determining a relationship between neurocognitive impairments, and social and functional outcome. Despite a number of comprehensive reviews on neurocognitive measures and reports on spatial working memory abnormalities in patients with schizophrenia when compared to healthy volunteers, there have been no meta-analyses of the extent of the abnormality in this group of patients. We reviewed 33 studies (from 1992 to 2005) on spatial working memory impairment in schizophrenia with the aim of providing a quantitative assessment of the consistency and the magnitude of the deficit. From the quantitative data analysis, it is evident that patients with schizophrenia are consistently more impaired on the spatial working memory measures than healthy controls. These impairments may be related to social disability and explain some cognitive deficits that characterize the clinical presentation of schizophrenia.