Working memory and long-term memory deficits in schizophrenia: is there a common substrate?

Patients with schizophrenia exhibit substantial deficits in both working memory (WM) and long-term memory (LTM) tasks. While these two forms of memory are generally viewed as distinct, recent evidence from healthy subjects has challenged the robustness of the double-dissociation between these two types of memory. In light of an emerging view of WM and LTM as being subserved by a largely overlapping network of brain regions, it is possible that WM and LTM deficits in patients with schizophrenia share a common neurobiological substrate. This review revisits the functional neuroimaging literature on both WM and LTM in patients with schizophrenia with these considerations in mind, and reveals a number of commonalities in research findings in both literatures. While there is a paucity of direct evidence bearing on whether patient deficits in these tasks arise from a common functional abnormality, the available literature is consistent with the hypothesis that these deficits have the same origin.