The Odor Context Facilitates the Perception of Low-Intensity Facial Expressions of Emotion

PLoS One. 2015 Sep 21;10(9):e0138656. doi: 10.1371/journal.pone.0138656. eCollection 2015.

Abstract

It has been established that the recognition of facial expressions integrates contextual information. In this study, we aimed to clarify the influence of contextual odors. The participants were asked to match a target face varying in expression intensity with non-ambiguous expressive faces. Intensity variations in the target faces were designed by morphing expressive faces with neutral faces. In addition, the influence of verbal information was assessed by providing half the participants with the emotion names. Odor cues were manipulated by placing participants in a pleasant (strawberry), aversive (butyric acid), or no-odor control context. The results showed two main effects of the odor context. First, the minimum amount of visual information required to perceive an expression was lowered when the odor context was emotionally congruent: happiness was correctly perceived at lower intensities in the faces displayed in the pleasant odor context, and the same phenomenon occurred for disgust and anger in the aversive odor context. Second, the odor context influenced the false perception of expressions that were not used in target faces, with distinct patterns according to the presence of emotion names. When emotion names were provided, the aversive odor context decreased intrusions for disgust ambiguous faces but increased them for anger. When the emotion names were not provided, this effect did not occur and the pleasant odor context elicited an overall increase in intrusions for negative expressions. We conclude that olfaction plays a role in the way facial expressions are perceived in interaction with other contextual influences such as verbal information.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Anger / physiology
  • Cues*
  • Emotions / physiology
  • Face / physiology
  • Facial Expression*
  • Fear / physiology
  • Female
  • Happiness
  • Humans
  • Male
  • Odorants*
  • Perception / physiology*
  • Smell / physiology
  • Young Adult

Grants and funding

This work was supported by the French National Agency for Research (project INTERFACE, EMCO, 2011), Paris; the Scientific Council for Research of Le Vinatier Hospital, Bron; the Regional Council of Burgundy (PARI grant), Dijon; The European Community (FEDER grant), Brussels; and the Institut Universitaire de France, Paris (to JYB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.