Scientists say they understand more about how the body responds to pleasurable touch. A team, including scientists from the Unilever company, have identified a class of nerve fibres in the skin which specifically send pleasure messages. And people had to be stroked at a certain speed – 4-5cm per second – to activate the pleasure sensation. They say the study, published in Nature Neuroscience, could help understand how touch sustains human relationships.
… If the stroke was faster or slower than the optimum speed, the touch was not pleasurable and the nerve fibres were not activated. The scientists also discovered that the C-tactile nerve fibres are only present on hairy skin, and are not found on the hand. “Our primary impulse as humans is procreation, but there are some mechanisms in place that are associated with behaviour and reward which are there to ensure relationships continue.”
See my blog entry from Sept 12, 2008 about this same topic. Pleasure: