Use of temporal context information in Alzheimer's disease.

Current theories of memory and memory dysfunction emphasize the importance of the use of contextual information in the storage and retrieval of specific episodes. Patients with lesions primarily in the diencephalon perform poorly on a measure of temporal recency, while those with temporal lobe amnesia are significantly better. The present study evaluated the ability of Probable AD patients to utilize information about temporal recency in the context of a recognition memory task. The performance of the AD patients was significantly impaired and resembled that of patients with Korsakoff's syndrome. The pattern of performance suggested that they were able to recognize which stimuli had been previously presented, but were unable to recall the correct temporal context. Further, there were no significant correlations between measures of temporal recency and those of frontal lobe function. These data suggest that AD patients, like other groups of patients with severe memory defects, are impaired at the use of context information in their attempts to remember recent events.