Vicarious neural reactivity to pleasant and unpleasant touch: a combined IVR-EEG study

The aim of the present work was to investigate how valence and physical perspective modulate the neural correlates of attentional and emotional processing of affective touch. We combined IVR and EEG to examine the neural reactivity to vicarious experiences of pleasant and unpleasant touch observed by two different perspectives. Healthy participants observed a caress (pleasant), a syringe (painful), or a little ball (neutral) stimulating their virtual right hand (first-person perspective, 1PP), or the right hand of another avatar sitting in front of them (third person perspective, 3PP) in IVR. Painful and pleasant stimuli were rated as less pleasant and more pleasant than neutral ones, respectively. Higher ownership scores were recorded for the 1PP virtual hand compared to the 3PP avatar’s hand. Middle latency EEG responses at occipital sites (time window: 160 400 ms), related to selective attention and stimulus relevance, were greater contingent to scenarios depicting pleasant and unpleasant compared to neutral touch, and specifically for 1PP conditions. Late latency activity at occipital sites (LPP; time window: 440 600 ms), reflecting arousal and motivational salience, was significantly lower for pleasant compared to neutral and unpleasant touch.