The human brain recruits similar brain regions when a state is experienced (e.g., touch, pain, actions) and when that state is passively observed in other individuals. In adults, seeing other people being touched activates similar brain areas as when we experience touch ourselves. Here we show that already by four months of age, cortical responses to tactile stimulation are modulated by visual information specifying another person being touched. We recorded somatosensory evoked potentials (SEPs) in 4-month-old infants while they were presented with brief vibrotactile stimuli to the hands. At the same time that the tactile stimuli were presented the infants observed another person's hand being touched by a soft paintbrush or approached by the paintbrush which then touched the surface next to their hand. A prominent positive peak in SEPs contralateral to the site of tactile stimulation around 130 ms after the tactile stimulus onset was of a significantly larger amplitude for the “Surface” trials than for the “Hand” trials. These findings indicate that, even at four months of age, somatosensory cortex is not only involved in the personal experience of touch but can also be vicariously recruited by seeing other people being touched.
Bibliographical noteFunding Information:
This research was supported by the British Academy/Leverhulme Trust Small Research Grant (No. SG122330) to SR, AJB and MB. Additional support was provided by the European Research Council (FP7/2007-2013; 241242), the Economic and Social Research Council UK (ES/K00882X/1) and the Bial Foundation (74/12). The authors would like to thank the parents and infants who took part in the study.
© 2017 The Authors
- Empathic sensing
- Multisensory development
- Social perceptual development
- Somatosensory evoked potentials
- Tactile perception