Smell your memories: Positive effect of odor exposure on recent and remote autobiographical memories in Alzheimer’s disease

Abstract

Introduction: There is a burgeoning interest in the effects of odor exposure on autobiographical memory in Alzheimer's disease (AD). We pursued this line of research by assessing the effect of odor exposure on the retrieval of recent and remote memories in AD. Method: Twenty-six patients with mild AD and 28 controls were tested in two conditions: with and without odor exposure. In each condition, participants were invited to retrieve two childhood memories, two adulthood memories, and two recent memories. Results: Analysis showed that AD patients produced a higher number of and more specific childhood memories, adulthood memories, and recent memories after odor exposure than without odor. Discussion: These findings demonstrate how odor exposure may alleviate anterograde and retrograde amnesia, at least when considering the ability of patients with mild AD to retrieve few recent or remote memories.

Sensory Cueing of Autobiographical Memories in Normal Aging and Alzheimer’s Disease: A Comparison Between Visual, Auditory, and Olfactory Information

“…In the present study, our goal was to determine the most relevant cue for AM retrieval in patients with early to mild AD, comparing odors, sounds and pictures. In line with the work of Glachet and col-191 leagues (i.e., [53][54][55][56]), we suggest that odors may [69], productive language with a verbal fluency task [70], episodic memory with the 5-word test [71], and attention and working memory with the forward and backward digit spans [72].…”

“…For example, the "imageability" of a verbal cue was found to influence the age, specificity, and vividness of AMs [41][42][43][44]. There is also support for the notion that visual dominance could influ- The effect of odors on AM retrieval in AD has recently been a key research topic for Glachet and colleagues [53][54][55][56]. Results from this line of research showed various advantages in exposing AD patients to odors before retrieving AMs, when comparing to the absence of sensory exposition.…”

Emotional and Phenomenological Properties of Odor-Evoked Autobiographical Memories in Alzheimer’s Disease

“…The study included 25 participants at the mild stage of AD and 23 healthy elderly adults. The sample size is similar to previous studies [2,21,46] using a close experimental design, and was sufficient to observe significant differences between AD and control participants in both experimental conditions (odor and odor-free). From the original sample of 36 AD participants, six participants were excluded from the study due to olfactory impairment, seven due to the very low scores on the cognitive battery, and one due to inability to follow the instructions provided.…”

Could Self-Consciousness Be Enhanced in Alzheimer’s Disease? An Approach from Emotional Sensorial Stimulation

“…They did not find significant effect of odor in terms of specificity and reminiscence in healthy people, suggesting that this type of cueing is particularly efficient when autobiographical memory is impaired. The team of Dr. Glachet [162] also found a positive effect of odor exposure on recent autobiographical memories in AD. Additionally, Glachet & El Haj [161] investigated emotional characteristics (arousal and valence) and subjective reliving of odor-evoked autobiographical memories in AD.…”

“…To our knowledge, only five studies have examined the impact of odor on autobiographical remembering in AD [123,[160][161][162][163]. All studies have demonstrated the positive effects of odor on personal event memories.…”