title: Chemosensory cues to conspecific emotional stress activate amygdala in humans.
abstract: Alarm substances are airborne chemical signals, released by an individual into the environment, which communicate emotional stress between conspecifics. Here we tested whether humans, like other mammals, are able to detect emotional stress in others by chemosensory cues. Sweat samples collected from individuals undergoing an acute emotional stressor, with exercise as a control, were pooled and presented to a separate group of participants (blind to condition) during four experiments. In an fMRI experiment and its replication, we showed that scanned participants showed amygdala activation in response to samples obtained from donors undergoing an emotional, but not physical, stressor. An odor-discrimination experiment suggested the effect was primarily due to emotional, and not odor, differences between the two stimuli. A fourth experiment investigated behavioral effects, demonstrating that stress samples sharpened emotion-perception of ambiguous facial stimuli. Together, our findings suggest human chemosensory signaling of emotional stress, with neurobiological and behavioral effects.
authors.affiliation: Department of Biomedical Engineering, Stony Brook University School of Medicine, Stony Brook, New York, United States of America. lmujicaparodi@gmail.com
authors.forename: Lilianne R
authors.initials: LR
authors.lastname: Mujica-Parodi
authors.forename: Helmut H
authors.initials: HH
authors.lastname: Strey
authors.forename: Blaise
authors.initials: B
authors.lastname: Frederick
authors.forename: Robert
authors.initials: R
authors.lastname: Savoy
authors.forename: David
authors.initials: D
authors.lastname: Cox
authors.forename: Yevgeny
authors.initials: Y
authors.lastname: Botanov
authors.forename: Denis
authors.initials: D
authors.lastname: Tolkunov
authors.forename: Denis
authors.initials: D
authors.lastname: Rubin
authors.forename: Jochen
authors.initials: J
authors.lastname: Weber
mesh_terms: D000679:Amygdala / Q000502:physiology*; D004644:Emotions; D006801:Humans; D008279:Magnetic Resonance Imaging; D013315:Stress, Psychological