children holding handsTouch is one of our most important senses for experiencing the world around us. Touch can also elicit emotion. Scientists are learning more about the critical role of the nerves involved in touch and how they affect us emotionally. A recent study documents a particular type of nerve cell that responds to gentle touch—the touch most often associated with emotion. The findings are important for understanding how humans interact with their environment and each other.

The researchers from Liverpool John Moores University in England and from Linköping University in Sweden reviewed studies on affective touch—a touch that invokes feeling or emotion. They identify a type of nerve called c-tactile afferents (CTs) that respond specifically to gentle touches like a slow stroke with a soft brush. The CT nerves are similar to pain-detecting nerves, but instead of alerting the brain to something harmful, they relay rewarding and pleasant sensations.

A system for emotional touching is just as important for humans as a system for pain detection. Emotional touch is used to nurture infants, connect with loved ones, or simply offer a reassuring pat on the back.

According to first author of the study Francis McGlone, PhD, “The evolutionary significance of such a system [of touch] for a social species is yet to be fully determined, but recent research is finding that people on the autistic spectrum do not process emotional touch normally, leading us to hypothesize that a failure of the CT system during neurodevelopment may impact adversely on the functioning of the social brain and the sense of self.”

The results of the research may have applications for people with autism spectrum disorders. The authors suggest that further research into affective touch could lead to therapies for children with autism spectrum disorders, who typically have some kind of touch-based sensitivity.

This research is published in the journal Neuron.

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