title: Chemosignals of fear enhance cognitive performance in humans.
abstract: It is well documented across phyla that animals experiencing stress and fear produce chemical warning signals that can lead to behavioral, endocrinological, and immunological changes in the recipient animals of the same species. Humans distinguish between fear and other emotional chemosignals based on olfactory cues. Here, we study the effect of human fear chemosignals on the speed and accuracy of cognitive performance. In a double-blind experiment, female participants performed a word-association task while smelling one of the three types of olfactory stimuli: fear sweat, neutral sweat, and control odor carrier. We found that the participants exposed to the fear condition performed more accurately and yet with no sacrifice for speed on meaningful word conditions than those under either the neutral or the control condition. At the same time, they performed slower on tasks that contained ambiguous content. Possible factors that could introduce bias, such as individual differences due to anxiety, verbal skills, and perceived qualities of the smells, were ruled out. Our results demonstrate that human fear chemosignals enhance cognitive performances in the recipient. We suggest that this effect originates from learned associations, including greater cautiousness and concomitant changes in cognitive strategies.
authors.affiliation: Psychology Department MS-25, Rice University, 6100 Main Street, Houston, TX 77005, USA. xdchen@rice.edu
authors.forename: Denise
authors.initials: D
authors.lastname: Chen
authors.forename: Ameeta
authors.initials: A
authors.lastname: Katdare
authors.forename: Nadia
authors.initials: N
authors.lastname: Lucas
mesh_terms: D000293:Adolescent; D000328:Adult; D003071:Cognition / Q000187:drug effects / Q000502:physiology*; D004644:Emotions / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D009812:Odorants; D010675:Pheromones / Q000494:pharmacology / Q000502:physiology*; D012016:Reference Values; D012680:Sensitivity and Specificity; D012903:Smell / Q000502:physiology*; D013268:Stimulation, Chemical; D014743:Videotape Recording
chemical_list: D010675:Pheromones