Negative Bias in the Perception and Memory of Emotional Information in Alzheimer Disease

Abstract

Background: There is some controversy about the ability of patients with Alzheimer disease (AD) to experience and remember emotional stimuli. This study aims to assess the emotional experience of patients with AD and the existence of emotional enhancement of memory. We also investigated the influence of affective state on these processes.

Methods: Sixty pictures from the International Affective Picture System were administered to 106 participants (72 patients with AD and 54 controls). Participants performed immediate free recall and recognition tasks. Positive and Negative Affect Schedule was used to assess the participants' current affect.

Results: Patients identified the valence of unpleasant pictures better than of others pictures and experienced them as more arousing. Patients and controls recalled and recognized higher number of emotional pictures than of neutral ones. Patients discriminated better the unpleasant pictures. A mood congruent effect was observed on emotional experience but not on memory. Positive affect was associated with better immediate recall and with a more liberal response bias.

Conclusion: Patients with AD can identify the emotional content of the stimuli, especially of the unpleasant ones, and the emotional enhancement of memory is preserved. Affective state does not explain the differences in the processing and memory of emotional items between patients and controls.

Keywords: Alzheimer disease; International Affective Picture System; emotional memory effect; memory; mental health.