Shared bodily sensations in the human somatosensory cortex: a SEPs study

Although feeling pain and touch has long been considered inherently private, recent neuroimaging and neurophysiologic studies hint at the social implications of this experience. Here we used somatosensory-evoked potentials (SEPs) to investigate whether mere observation of painful and tactile stimuli delivered to a model would modulate neural activity in the somatic system of an onlooker. To explore whether hypothesized SEPs modulation contingent upon the observation of others’ pain or touch was related to different aspects of the subjective experience of others’ sensations, subjects were asked to rate along a 0–10 VAS, the Intensity and Unpleasantness of the sensation purportedly experienced by the model (other-oriented measures) and Aversion (self-oriented measure) induced by each movie. Viewing video-clips showing pain and tactile stimuli delivered to others respectively increased and decreased the amplitude of the P45 SEPs component that reflects the activity of the primary somatosensory cortex (SI). These modulati