Smelling the goodness: sniffing as a behavioral measure of learned odor hedonics

Pairing an odor and taste can change ratings of the odor’s perceptual and hedonic characteristics. Behavioral indices of such changes are lacking and here we measured sniffing to assess learned changes in odor liking due to pairing with sweet and bitter tastes. Participants were divided on their liking for sweetness, as well as dietary disinhibition (TFEQ-D scale), both of which influence hedonic odor-taste learning. In sweet likers, both sniff duration and peak amplitude increased for the sweet-paired odor. Sniff magnitude decreased for sweet- and quinine-paired odors in sweet-dislikers, and sweet likers smelling the quinine-paired odor. In sweet-likers, liking for the sweet-paired odor increased with both TFEQ-D score and hunger, and sniff magnitude with TFEQ-D only. There were no predictors of changes in response to the quinine-paired odor. Brief co-experience of odors with sweet tastes can lead therefore to measurable changes in sniffing, providing a novel behavioral index of odor liking.