The ARTTOUCH project aims to uncover how basic touch is encoded by the skin and processed in the brain, as well as how more complex sensations are generated, such as wetness and tactile pleasantness. To achieve this, the project uses a specialist technique that is only conducted few groups in the world, namely, microneurography. This allows us to access human peripheral nerves, such as the nerves in the hand, and record from a single nerve fiber that receives information from a receptor in the skin. In healthy humans, we insert a small needle electrode into the skin and into a nerve, to record the responses to touch. We ask the human participant to touch different textures and surfaces, then we record the responses from different touch receptors (mechanoreceptors). We have found that when a person actively touches a surface, distinct properties of the surface and movement are encoded by different types of mechanoreceptor, from the initial contact, to sliding movements, to the offset of contact. Further, when we apply drops of water to the skin, we find that only the most sensitive mechanoreceptors respond, and only one type in the glabrous skin of the hand, and these encode the vibration of the drop on the skin. We also use an extension of the technique of microneurography, where we record from a single touch fiber and then artificially stimulate it via re-injecting a small electrical current. This produces an artificial sensation, a very small point of touch, which differs depending on the mechanoreceptor stimulated. For example, one type produces vibration and another the sensation of pressure. We have found that human participants can discriminate between small differences in trains of electrical stimulation injected into a single fiber and we have also mapped the responses generated from this in the brain. We have presented and published this work in a number of ways to disseminate the information to the scientific community, through invited talks, conferences symposia and posters, videos, and journal papers. Further, we have communicated this to a very large public audience through the media, internet, social media, popular press, and talks.
