Claudia Hammond looks at the neuroscience behind our sense of touch. Why does a gentle touch from a loved one make us feel good? This is a question that neuroscientists have been exploring since the late 1990's, following the discovery of a special class of nerve fibres in the skin. There seems to be a neurological system dedicated to sensing and processing the gentle stroking you might receive from a parent or lover or friend, or that a monkey might receive from another grooming it. Claudia talks to neuroscientists Victoria Abraira, Rebecca Bohme, Katerina Fotopoulou and Francis McGlone who all investigate our sense of emotional touch, and she hears from Ian Waterman who lost his sense of touch at the age of eighteen.