Non-food odors and the duality of smell: Impact of odorant delivery pathway and labeling convention on olfactory perception

• Published in: Physiology & behavior Vol. 238; p. 113480
• Main Authors: Hannum, Mackenzie E., Fryer, Jenna A., Simons, Christopher T.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2021
• Subjects: behavior; cognition; Cognitive strategy; epithelium; flavor; Floral aromas; Labeling convention; Lavandula; odor compounds; odors; Olfaction; olfactory perception; Orthonasal; Pedunculata; Retronasal; smell; Orthonasal; Cognitive strategy; Floral aromas; Labeling convention; Olfaction; Retronasal
• ISSN: 0031-9384; 1873-507X; 1873-507X
• DOI: 10.1016/j.physbeh.2021.113480

•Route of administration impacts odor perception.•Orthonasal and retronasal perception of non-food odors differ.•Odor labels affect performance in an odor matching task.•Odor perception is a function of stimulus quality, cognitive strategy, and stimulus name. The olfactory system encompasses two perceptual pathways (orthonasal and retronasal) that activate the same receptors in the olfactory epithelium yet are thought to elicit different perceptions. Presently, a novel matching paradigm was employed using a non-food flavor set with low retronasal familiarity (honeysuckle, lavender, rose, and jasmine) to evaluate the effect of odor type on the Duality of Smell. Additionally, the influence of cognitive strategies used by subjects was assessed by manipulating the naming convention seen by the subjects: familiar (Honeysuckle, Lavender, Rose, Jasmine), unfamiliar (Inodora, Pedunculata, Beggeriana, Didymum), and generic (A, B, C, D). Subjects were presented with a reference, either in a vial (orthonasal delivery, ON) or a 2 oz. cup (retronasal delivery, RN) and instructed to match the same aroma from four unknowns, evaluated either by the same delivery route (congruent, e.g., ON-ON, RN-RN) or different route (incongruent, e.g., ON-RN, RN-ON) than the reference evaluation. All possible combinations of orthonasal and retronasal delivery for the reference and unknowns (e.g. ON-ON, RN-RN, ON-RN, RN-ON) were assessed by all subjects. Matching performance and signal detection measures indicated that, on average, subjects performed significantly better in the congruent conditions than in the incongruent conditions. These results suggest perceptual quality of aromas is route dependent and extend the Duality of Smell hypothesis to samples with low retronasal familiarity such as non-food odors. Labeling convention also had an impact on performance but, surprisingly, not in the direction anticipated. Indeed, as the information contained in the label decreased from familiar to generic reference names, performance increased. Moreover, depending on the labeling convention used, certain aromas were easier to match than others. The present research suggests odorant matching is a function of stimulus quality, cognitive strategy, and labeling convention.