Enhanced sensitivity to odors due to chemosignals associated with anxiety

Chemocommunication is important in human nonverbal communication. Behavioral effects of anxiety chemosignals on recipients are established but it is unknown whether odor sensitivity can be modulated by such stimuli. We tested recipients' sensitivity to phenylethyl alcohol (PEA) and n-butanol after exposure to anxiety chemosignals, neutral chemosignals and blank condition. As fourth condition, a horror movie was shown, to compare the effects of visual stimuli and chemosignals on odor sensitivity. Odor sensitivity for PEA was significantly increased by anxiety chemosignals compared to blank condition. No change in odor sensitivity was evident for n-butanol. We also investigated the composition of the applied chemosensory stimuli using untargeted one-dimensional gas chromatography-mass spectrometry (GC-MS) and -olfactometry (GC-O). Considering GC-MS data, several compounds were found with significantly higher normalized peak areas in anxiety sweat samples compared to the neutral samples. GC-O analysis indicated that the carboxylic acids dodecanoic acid and 3-hydroxy-3-methylhexanoic acid were potential main contributors to the odor of anxiety sweat samples, whereby tetradecanoic acid and patchouli alcohol were those of the odor of neutral sweat samples. This study provides evidence that anxiety chemosignals can improve odor sensitivity and constitutes a further step toward elucidating the composition of sweat samples used in chemical communication research.