Naama Zur
I am a 5th year PhD candidate in the Interdisciplinary Program in Neuroscience at Georgetown University. I am investigating neural mechanisms of vicarious social processes and the moderating role of empathy. Iām interested in the role of somatosensory cortex in emotional responses to vicarious experiences, and how individual differences in trait empathy, may shape this process. I use transcranial direct current stimulation (tDCS) to assess neural activity during observed social touch, and fMRI to examine somatosensory cortex activity while participants hold hands with either a familiar partner or a stranger, who are under threat of receiving an electric shock.
The Role of Somatosensory Cortex and Trait Empathy in Perception of Positive Social Touch: A tDCS Study
Vicarious social touch describes the sensory and affective experiences that arise when observing others engage in socially meaningful physical contact. Previous work has shown that excitatory stimulation of the primary somatosensory cortex (SI) alters the perception of direct, non-social touch in a somatotopically specific manner. However, it remains unclear whether SI also plays a role in processing the affective content of observed social touch. In the present study, we examined whether increasing SI excitability via anodal transcranial direct current stimulation (tDCS) modulates emotional responses to visual depictions of social touch, and whether these effects depend on individual differences in trait empathy. Fifty-nine adults (ages 19ā36) rated the emotional intensity of images depicting humans or objects, either engaging in touch or not, across two experimental sessions involving sham and anodal tDCS applied over the right or left SI. Participants additionally completed self-report measures assessing cognitive and emotional empathy. Results revealed that both empathy dimensions moderated the effects of SI stimulation on emotional evaluations. Individuals high in cognitive empathy reported heightened emotional responses to images of human social touch during anodal relative to sham stimulation, whereas those low in cognitive empathy exhibited increased emotional ratings for images of objects in contact under anodal tDCS. Conversely, lower levels of emotional empathy were associated with reduced emotional ratings during anodal stimulation when viewing human images, regardless of the presence of touch. Together, these findings indicate that SI contributes to affective responses to social visual stimuli, with its influence contingent on individual empathy-related traits.