Logo: to the web site of Uppsala University

According to the facial feedback hypothesis, facial muscles do not only express emotions, they also have the ability to modulate subjective experiences of emotions and to initiate emotions. This study examined the voluntary facial action technique, where participants were instructed to react with the Zygomatic major muscle (smile) or the Corrugator supercilii muscle (frown) when exposed to different stimuli. The results demonstrate that the technique effectively induces facial feedback effects. Through use of this technique we further addressed three important areas of facial feedback and found, first, that facial feedback did not modulate the experience of positive and negative emotion evoking stimuli differently. Second, the modulating ability provided significant feedback effects, while the initiating ability did not. Third, an effect of feedback remained and could be detected even some time after the critical manipulation. It is concluded that the present technique can be used in the future study of facial feedback.

The facial feedback hypothesis states that facial actions modulate subjective experiences of emotion. Using the voluntary facial action technique, in which the participants react with instruction induced smiles and frowns when exposed to positive and negative emotional pictures and then rate the pleasantness of these stimuli, four questions were addressed in the present study. The results in Experiment 1 demonstrated a feedback effect because participants experienced the stimuli as more pleasant during smiling as compared to when frowning. However, this effect was present only during the critical actions of smiling and frowning, with no remaining effects after 5 min or after 1 day. In Experiment 2, feedback effects were found only when the facial action (smile/frown) was incongruent with the presented emotion (positive/negative), demonstrating attenuating but not enhancing modulation. Finally, no difference in the intensity of produced feedback effect was found between smiling and frowning, and no difference in feedback effect was found between positive and negative emotions. In conclusion, facial feedback appears to occur mainly during actual facial actions, and primarily attenuate ongoing emotional states.

According to the facial feedback hypothesis, emotion-relevant facial actions influence subjective emotional experiences. Most theories propose that feedback primarily originates from facial muscles, but the facial skin has also been suggested as a possible source. We investigated if feedback from the skin is critical by anesthetizing the facial skin to prevent potential feedback from the skin as compared to a non-anesthetized control condition. A second aim was to replicate a recent finding that only incongruent, but not congruent, voluntary facial actions produce feedback effects. The voluntary facial action technique was used to evaluate if participants rated their experienced pleasantness of viewing pictures of happy and angry faces differently as a function of voluntarily performed smiles or frowns. The results showed clear feedback effects with mean ratings of pleasantness significantly higher across all conditions when they smiled as compared to frowned. Importantly, these effects were prominent and similar regardless of if the facial skin was anesthetized or not, indicating that feedback from the facial skin is not critical for feedback effects to occur. Moreover, these feedback effects were obtained exclusively as a result of incongruent facial actions, replicating the earlier finding.