Investigating the Evolution of Odor-Evoked Memories Retrieval in Normal Aging: Theoretical and Clinical Implications.

Background: Olfactory-based cognitive stimulation is frequently proposed for memory-impaired patients (namely dementia patients), but little is known about the scientific rationale underlying odor choice.

Objectives: Here, we aimed at investigating the evolution of the olfactory experience related to memory evocation in normal aging. Methods. We presented 20 odorants to 25 Young Adults (YA), 36 "young" Older Adults (OA; 65 - 74y) and 26 "old" OA (75 - 89y) and asked them to freely report what each odor evoked to them. Responses were analyzed using both univariate inferential statistics and multivariate descriptive analysis.

Results: Results showed that the ability to experience phenomenological properties of evoked memories decreases with advancing age. Odor identity is increasingly used as a retrieval cue with age, providing necessary support for OA retrieval strategies. However, semantic information does not enhance the chances for old-OA to experience memories' phenomenological properties.

Conclusion: Tailoring the choice of odors during stimulating activities is therefore crucial. In this respect, we provided a limited selection of the most well-characterized odorous stimuli and sorted them based on the phenomenological experience they're more likely to trigger across ages.