Superior Orthonasal but Not Retronasal Olfactory Skills in Congenital Blindness

• Published in: PloS one Vol. 10; no. 3; p. e0122567
• Main Authors: Gagnon, Lea, Ismaili, Abd Rahman Alaoui, Ptito, Maurice, Kupers, Ron
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30.03.2015; Public Library of Science (PLoS)
• Subjects: Adaptive technology; Adult; Aroma compounds; Blindness; Blindness - congenital; Blindness - physiopathology; Body mass; Body mass index; Body size; Brain research; Case-Control Studies; Cooking; Female; Flavors; Food; Food availability; Genetic disorders; Handicapped assistance devices; Humans; Identification; Laboratories; Male; Middle Aged; Mouth; Mouth - physiopathology; Nasal Cavity - physiopathology; Neurosciences; Odorants; Odors; Olfactory Pathways - physiology; Olfactory perception; Olfactory Perception - physiology; Optometry; Perception; Pharmacology; Premature birth; Skills; Smell - physiology; Taste perception; Taste Perception - physiology; Denmark; Canada; Montreal Quebec Canada; Quebec Canada
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0122567

Sight is undoubtedly important for finding and appreciating food, and cooking. Blind individuals are strongly impaired in finding food, limiting the variety of flavours they are exposed to. We have shown before that compared to sighted controls, congenitally blind individuals have enhanced olfactory but reduced taste perception. In this study we tested the hypothesis that congenitally blind subjects have enhanced orthonasal but not retronasal olfactory skills. Twelve congenitally blind and 14 sighted control subjects, matched in age, gender and body mass index, were asked to identify odours using grocery-available food powders. Results showed that blind subjects were significantly faster and tended to be better at identifying odours presented orthonasally. This was not the case when odorants were presented retronasally. We also found a significant group x route interaction, showing that although both groups performed better for retronasally compared to orthonasally presented odours, this gain was less pronounced for blind subjects. Finally, our data revealed that blind subjects were more familiar with the orthonasal odorants and used the retronasal odorants less often for cooking than their sighted counterparts. These results confirm that orthonasal but not retronasal olfactory perception is enhanced in congenital blindness, a result that is concordant with the reduced food variety exposure in this group.