Older and younger people experience similar long-term olfactory habituation
Olfactory habituation corresponds to a decreased behavioral or perceptual response to an odor after a prolonged exposure to this odor. We investigated whether long-term olfactory habituation is similar in younger (<35 years old) and older adults (>50). Fifty seven participants performed a five week longitudinal study. They were exposed to one of two odors (manzanate, irone alpha) for two weeks at home. Olfactory detection thresholds for both odors were measured before and after exposure. Results showed that the two age groups behaved similarly. The long-term exposure to an odor led to a temporary lower sensitivity to the odor. IA thresholds were more sensitive to the time of exposure with the odor than MA thresholds. One week after termination of exposure, participants fully recovered and even became more sensitive to both odors. No cross-habituation was found between the two odors. Our findings highlight that long-term exposure is specific to the odor habituated, behaves the same in young and older adults and is fully reversible in both age groups after one week.