Rochelle Ackerley : Stimulating single tactile afferents in humans : sensations felt and cortical responses generated [LNIA, Marseille]

Our touch system presents a complex network of afferents, where a multitude of sensations can be felt, from more simple facets like vibration to blended percepts such as wetness. The technique of microneurography permits recordings from single human afferents, via the insertion of an electrode into a peripheral nerve. Mechanical stimuli can be applied to the skin and the responses from tactile afferents can be recorded. This can be taken one step further, by recording from a single afferent and then stimulating the same one, by applying a small electrical current down the electrode. In essence, it is possible to record signals from one mechanoreceptive afferent, then artificially stimulate it to produce a perceptual tactile experience, where questions can be asked about the illusory sensation generated. I combine this approach with high resolution brain imaging, to understand the precise somatosensory circuits that encode such fundamental touch. These findings can be applied in the domain of emulating cutaneous signals, such as recovering touch in amputees. The implementation of somatosensory feedback for missing body parts represents an immense step forward in the development and use of prostheses.