Effects of olfactory stimulation on autobiographical memory in Alzheimer's disease

Abstract

A body of research showed positive effects of olfactory stimulation on autobiographical memory. However, no research has evaluated the influence of such stimulation on autobiographical memory in Alzheimer's disease. We invited participants with Alzheimer's disease and controls to retrieve autobiographical memories when exposed to odor and in a control condition without odor. Compared to memories evoked without odors, olfactory-evoked autobiographical memories were more specific and accompanied by more subjective experience of reviviscence in patients with Alzheimer's disease. However, no such benefit was observed in control participants. Interestingly, when compared to memories evoked without odors, olfactory-evoked autobiographical memories were retrieved faster in all participants. Our findings demonstrate positive effects of olfactory stimulation on two components (specificity and reviviscence) of autobiographical retrieval in Alzheimer's disease. This study offers solid foundations for the adaptation of olfactory stimulation in nursing homes in the framework of reminiscence therapy in order to preserve the sense of identity in patients with Alzheimer's disease as long as possible.