Alzheimer's Disease usually begins with massive a huge impairments in explicit memory but the question of the efficiency of implicit memory remains unresolved since studies using stem completion tasks have led to contradictory results.

The present study used target words embedded in coherent sentences within significant short texts. During the inspection phase, patients read the text aloud. During the completion phase, patients wrote the first word which come to mind in order to complete a three letters stem A final recognition phase explored explicit memory performance.

32 Alzheimer patients were compared to a matched sample of elderly persons. Reading times differed between groups, revealing the difficulty of the task for Alzheimer patients. Recognition was dramatically lower in Patients, thus confirming the alteration of explicit memory in this pathology. However, the priming effect (e.g. the tendency to complete the stem with the aid of a previously explored word) was present in Alzheimers Disease as in elderly persons. Moreover, the priming level was identical in the two groups.

These results can be explained neither by an explicit memory bias nor by perceptual priming They suggest that conceptual and semantic processing are preserved during the light and moderate periods of this disease.