Touch perception occurs when the skin is moved or touched. This includes indentation, such as when a finger presses against your skin; vibration, such as when you touch an active electric toothbrush; and stretching, such as when someone scratches your back or pulls on your skin. Such mechanical stimulation of the skin activates one or more of the four types of mechanoreceptors in your skin. Mechanoreceptors are sensory receptors in the skin that transduce physical movement on the skin into neural signals, which are sent to the brain. Now, take a deep breath, as we need to get a bit technical and introduce a bit of jargon. There is no avoiding it—touch perception is complex, with multiple kinds of receptors, each with a multisyllabic name.
The four types of mechanoreceptors are called SAI mechanoreceptors, SAII mechanoreceptors, FAI mechanoreceptors, and FAII mechanoreceptors. Each mechanoreceptor differs on a number of relevant dimensions, which are important to producing a complex touch response.
Explore the videos on these tabs to learn more about mechanoreceptors.
Listen to this rap about mechanoreceptors.
Listen to this lecture about sensory nerves and mechanoreceptors by Dr. John Campbell.