Relationship between asymmetric nostril use and human emotional odours in cats

Cat social behaviour and cognition has received a growing interest during the last decades. Recent studies reported that cats efficiently engage in interspecific communication with humans and suggest that cats are sensitive to human emotional visual and auditory cues. To date, there is no evidence on the social and informative role of human emotional odours, which may affect human-cat communication. In this study, we presented cats with human odours collected in different emotional contexts (fear, happiness, physical stress and neutral) and evaluated the animals' behavioural responses. We found that "fear" odours elicited higher stress levels than "physical stress" and "neutral", suggesting that cats perceived the valence of the information conveyed by "fear" olfactory signals and regulate their behaviour accordingly. Moreover, the prevalent use of the right nostril (right hemisphere activation) with the increase of stress levels, particularly in response to "fear" odours, provides first evidence of lateralized emotional functions of olfactory pathways in cats.