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

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 nonedible 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.