The effect of perceived odour edibility induced via conditioning on olfactory habituation

Abstract

Previous research shows that edibility (top-down feature) could modulate olfactory habituation, as habituation follows a different trend for food or non-food odours. However, the impact of bottom-up features of the stimuli (e.g., trigeminality) cannot be ruled out. To minimize such influences, in the present experiment, forty-four participants completed a habituation paradigm while being presented with the same odour (i.e., vanilla) that could be associated both to food and non-food stimuli. In the conditioning phase, participants were exposed to the vanilla odour coupled either with food (edible group) or with non-food pictures (non-edible group). The conditioning protocol affected the perceived edibility of the vanilla odour, namely the edible group rated the odour significantly more edible than the non-edible group. In the habituation phase, participants were exposed to the same vanilla odour in a block of 20 trials. They rated the perceived odour intensity and pleasantness after each trial. Linear mixed-effects models showed that the odour intensity decreased over time only in the non-edible group. While the pleasantness decreased in both groups. Our findings show that, when minimizing the influence of other possible olfactory features (e.g., trigeminality, pleasantness), odour edibility modulates olfactory habituation.