Neural responses to social touch with different emotional valences: an fNIRS study

Social touch conveys a wealth of social and emotional information in interpersonal contexts. Despite the complexity of social touch in real-life situations, past research has often focused on CT-targeted social touch, neglecting the social-emotional expression in real social touch. Thus, we created a social touch paradigm in which the stimuli were derived from the Social Affective Touch Database. Using fNIRS, we investigated neural responses to social touch under different emotional valences. Our study found that under different touch conditions, the primary somatosensory cortex (S1), the superior temporal sulcus (STS), and the prefrontal cortex (PFC) were broadly activated. Additionally, we also found that the PFC mediates the pathway between S1 and Premotor Cortex-Somatomotor Cortex (PMC-SMC) for different emotional valence stimuli in the tactile modality. Our findings contribute to a deeper understanding of how social touch is linked to social emotions of different valences and ultimately heightened our awareness of the PFC function in social cognition and emotional processing.