Perception of facial expressions involves emotion specific somatosensory cortex activations which are shaped by alexithymia

Abstract

Somatosensory cortex (SCx) has been shown to crucially contribute to early perceptual processes when judging other's emotional facial expressions. Here, we investigated the specificity of SCx activity to angry, happy, sad and neutral emotions and the role of personality factors. We assessed participants' alexithymia (TAS-20) and depression (BDI) levels, their cardioceptive abilities and recorded changes in neural activity in a facial emotion judgment task. During the task, we presented tactile probes to reveal neural activity in SCx which was then isolated from visual carry-over responses. We further obtain SCx emotion effects by subtracting SCx activity elicited by neutral emotion expressions from angry, happy, and sad expressions. We find preliminary evidence for distinct modulations of SCx activity to angry and happy expressions. Moreover, the SCx anger response was predicted by individual differences in trait alexithymia. Thus, emotion expressions of others may be distinctly presented in the observer's neural body representation and may be shaped by their personality trait.