Neural empathic reactions to pain and touch are reduced by physical barriers between two individuals

Background- Empathy might be shaped by socio-affective relationships between individuals, such that neural empathic reactions are magnified for affectively close others compared to strangers. In one of our previous investigation, we demonstrated that empathy may be also modulated by the physical distance between individuals. It is still to be understood the underlying mechanism through which manipulating the physical distance may interfere with empathic responses. One such possible mechanism refers to the notion of ‘interaction space’, the shared reaching space of two individuals. Within this framework, the sharing of affective states might be sensitive to the physical distance between individuals. Methods - The goal of the present experiment was to investigate whether interfering with the ‘interaction space’ could modulate ERP empathic reactions to both pain and touch. Participants were exposed to faces stimulated by either a needle or a Q-tip under both one condition in which they seated in front of the screen (no-plexiglass condition) and a second critical condition in which a plexiglass was interposed between them and the screen (plexiglass condition). We expected reduced neural responses to both pain and touch in the plexiglass condition when compared to the no-plexiglass condition as a result of the interference with the interaction space.