Invisible side of emotions: somato-motor responses to affective facial displays in alexithymia.

According to recent theories, the detection of emotions involves somatic experiences. In this study, we investigated the relation between somatic responses to affective stimuli, emotion perception, and alexithymia. Variations in automatic rapid facial reactions (RFRs) were measured in a selected population of participants with high and low levels of alexithymia (HA and LA, respectively). Electromyographic activity was recorded from the corrugator supercilii and the zygomaticus major, while participants performed a gender classification task on faces expressing various emotional states. LA participants showed congruent RFRs in response to both fearful and happy stimuli. On the other hand, HA participants did not show congruent RFRs in response to fearful faces. They showed congruent, but delayed, RFRs in response to happy faces. These results provide evidence of a deficit in somato-motor emotional processing in people with high alexithymic personality traits, and thus support the hypothesis that alexithymia is associated with a deficit in emotional embodiment.