Scents boost preference for novel fruits.

When faced with a novel food, multisensory information that includes appearance and smell is a very important cue for preference, categorization, and the decision of whether or not to eat it. We elucidated whether olfactory information leads to biased visual categorization of and preference for fruits, even when odors are presented subliminally. We employed morphed images of strawberries and tomatoes combined with their corresponding odorants as stimuli. Participants were asked to categorize the images into either of two categories, to evaluate their preference for each visual image, and to judge the presence/absence of the odor. Results demonstrated that visual categorization was not affected by the odor manipulation; however, preference for uncategorizable images increased when odors were presented regardless of the participant's awareness of the odor. Our findings suggest that visual preference for novel fruits is based on both conscious and unconscious olfactory processing regarding edibility.