Neural correlates of recognition memory with and without recollection in patients with Alzheimer's disease and healthy controls

To dissociate recognition memory with and without recollection, event-related potentials (ERPs) of patients with Alzheimer's disease (AD) and matched controls were recorded in a test of verbal recognition memory accompanied by a source judgement. AD patients who had smaller hippocampi showed a disability to recollect the study context (source). Their ERPs elicited by correctly recognized old words compared to new items were more positive only between 300 and 500 ms with a maximum over the frontal scalp. Controls exhibited a sustained world/new effect over left temporoparietal and frontal sites. The present findings suggest that preserved recognition memory in patients with mild AD is independent of hippocampally mediated processes recollecting episodic memories. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.