Explicit and implicit memory for emotional stimuli in depressed elderly and Alzheimer's disease]

It is well known that emotional events are better recalled than neutral events. It indicates that memory is affected by the emotional content of stimuli. Since psychiatric and neurodegenerative diseases produce qualitatively and quantitively different memory and emotional disorders, a better understanding of their relations should improve our knowledge about memory and emotion interaction. We present here a review of recent studies that examined the effects of emotions on episodic (explicit) memory and on perceptual and conceptual priming (implicit memory) in depression and in Alzheimer's disease. Several studies of memory in depressed patients reported a tendency toward recall of negatively toned material indicating the existence of a bias toward processing of mood-congruent information. On the other hand, an enhancement of memory performance is observed in Alzheimer's disease when positive and negative stimuli are used.