Thursday, 14 March 2013
Lara Maister and her colleagues used the "enfacement" illusion, in which a person watches a two-minute video of a face being stroked with a cotton bud, while at the same time their own face is stroked in synchrony. People who experience this illusion tend to rate the face in the video as being more similar to their own, and, if they see the face cut, they show a physiological stress reaction as if the wound was theirs.
In the study, 15 female participants were challenged with identifying the emotional expression shown by a woman in a photo - either happy, fearful or disgusted. The photos had been morphed with neutral expressions to varying degrees, leading to seven different levels of task difficulty.
The key finding was that the participants were significantly better at recognising the facial expression of fear after they'd experienced the enfacement illusion for the face showing the fear. Simply watching a two-minute video of the person displaying fear didn't lead to this subsequent performance boost, neither did a "sham" version of the illusion in which the stroking of the model's and participant's face is out of synch. Another detail - the genuine version of the illusion led to enhancement of fear recognition only, with no effect on recognising happiness and disgust.
The main result is consistent with past research suggesting that we recognise emotions in other people by simulating their state in our brains. It's as if we temporarily embody the person we are empathising with. Related to this, people with a rare condition known as mirror-touch synaesthesia (they experience touch when they see someone else touched) show enhanced facial expression recognition.
It's curious that the enfacement illusion only enhanced the recognition of fear, but then previous studies have suggested that this emotion, more than others, is recognised through a process of embodying the person who is afraid. This makes evolutionary sense too. There are obvious advantages in responding to the sight of a fearful ally by preparing one's own body for a threat.
"Our results suggest that the way we represent the relationship between the bodies of self and other is an important factor in the somatosensory simulation of emotions," the researchers said, "and furthermore, demonstrate that such a process is sensitive to multisensory intervention."
Maister L, Tsiakkas E, and Tsakiris M (2013). I feel your fear: Shared touch between faces facilitates recognition of fearful facial expressions. Emotion (Washington, D.C.), 13 (1), 7-13 PMID: 23356565
Image reproduced with permission of the first author.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.