The coding of tactile exploration by skin and muscle afferents using microneurography in humans

Rochelle Ackerley

To: Aix-Marseille University, France

From: University of Gothenburg

Project abstract

How does touch shape our actions? The aim of the proposal is to investigate the naturalistic behaviour involved during tactile exploration. A unique and novel approach will be used to record from human nerves during self-generated, active touch. The electrophysiological technique of microneurography allows axonal recordings from single afferents in awake, healthy humans. Laboratories from the University of Gothenburg, Sweden and Aix-Marseille University, France have used this technique to study tactile and muscle afferents, respectively, for more than 30 years each. The current project will bring together the expertise from these laboratories to explore how tactile and muscle afferents alter their firing patterns during active touch using the hands; something that has not previously been attempted. We hypothesise that different afferents will show specific modulations to both the surface being touched and the goal of the movement (e.g. to assess whether the surface is rough, pleasant or sticky). The will generate physiological data that represents neuronal responses during natural touching behaviour, whereas previous studies have always applied passive stimulation. This approach will advance the field of sensorimotor control to give unrivalled information about the integration of tactile and muscle input during exploratory touch. The resulting conclusions are useful in rehabilitative medicine, such as the restoration of sensations in amputees. In understanding how the healthy system works, it is possible to apply these ideas and strategies in incorporating real-time feedback in prostheses through intra-neural stimulation of afferents, using the natural firing patterns.