Memory for temporal order in patients with schizophrenia

There is some evidence that memory for temporal order is a process that may be impaired independently of other forms of memory. For example. patients with Korsakoff's syndrome have been shown to have poorer temporal-order mem ory than other amnesic patients, despite item memory being equivalent. pati ents with schizophrenia have been reported to have a variety of memory prob lems, although memory for the order of events has not been examined very fr equently. In this study, we tested memory for temporal order in patients wi th schizophrenia and in control subjects. Subjects were presented with two lists of 15 words (at two different times) and were Eater asked to reproduc e the order of each list from a random array of the words. In both versions of the test, patients with schizophrenia were impaired in placing the item s in the correct temporal order. Recall and recognition of the actual words used to comprise the lists were also impaired in the schizophrenic patient s. However. when recall measures were covaried, and when patients were matc hed with controls for recall, post-hoc group differences in temporal memory were eliminated. In contrast, covarying recognition (indexed by d' or matc hing for recognition) did not eliminate group differences. Therefore, altho ugh memory for temporal order is compromised in patients with schizophrenia . this deficit is highly correlated with generally poorer item-specific mem ory retrieval (i.e.. recall). It is possible that both impairments are due to some third process that underlies and aids in the reconstruction of epis odes. (C) 2000 Elsevier Science B.V. All rights reserved.