Life-span stability in olfactory sensitivity.

Abstract

Assessed the olfactory acuity of 120 6-94 yr olds by means of magnitude production in a simple motor task. 7 concentrations of n-propanol, ranging from 100 to 1.56%, served as odorants. Remarkable consistency across concentrations was found in Ss of all ages, those in the younger and older age groups generating the most similar functions. Evidence of olfactory decline in the oldest Os was lacking, suggested only by the greater incidence of nonresponse at weaker concentrations in the intermediate 40-50 yr group. It is proposed that phylogenetically and ontogenetically early sensitivities (e.g., olfaction and touch) are likely to be among the last to decline when the organism is under stress as, for example, in aging. (27 ref)

Individual Differences in Retronasal Odor Responsiveness: Effects of Aging and Concurrent Taste

“…Literature on the effect of aging on suprathreshold measures of odors is somewhat mixed in results. Some studies showed diminished intensity ratings with age (Stevens et al 1982;Stevens and Cain 1985;Wysocki and Gilbert 1989), while others did not see the effect (Rovee et al 1975;Cowart 1989). Discrepancies between the current and other studies can be explained by differences in study population, odorants tested, and experimental procedures.…”

Tests of human olfactory function: Principal components analysis suggests that most measure a common source of variance

“…In the present work, such recruitment could include fibers from free nerve endings of the trigeminal nerve that are distributed throughout the nasal mucosa, since amyl acetate is known to have trigeminal stimulative properties at higher concentrations and receives intensity ratings from anosmics similar to those observed in normosmics (Doty et aI., 1978). Such a notion may explain why some suprathreshold scaling parameters are insensitive to changes in the ability to smell related to age and Alzheimer's disease (e.g., Green et aI., 1989;Rovee, Cohen, & Shlapack, 1975).…”

Olfactory dysfunction and its measurement in the clinic and workplace

“…Indeed, the well-established age-related alterations in olfactory function were completely missed in one study that employed rating scales, leading to the erroneous conclusion that olfaction is largely impervious to agerelated changes (Rovee et al 1975).…”