Abstract
Movement planning and execution lead to changes in somatosensory perception. For example, tactile stimuli on a moving compared to a resting limb are typically perceived as weaker and later in time. This phenomenon is termed tactile suppression and has been linked to a forward model mechanism which predicts the sensory consequences of the self-generated action and as a result discounts the respective sensory reafferences. As tactile suppression is also evident in passive hand movements, both predictive and postdictive mechanisms may be involved. However, its functional role is still widely unknown. It has been proposed that tactile suppression prevents sensory overload due to the large amount of afferent information generated during movement and therefore facilitates processing of external sensory events. However, if tactile feedback from the moving limb is needed to gain information, e.g. at the fingers involved in grasping, tactile sensitivity is less strongly reduced. In the talk, I will present recent results from a series of psychophysical experiments that show that tactile sensitivity is dynamically modulated during the course of the reaching movement depending on the reach goal and the predicted movement consequences. These results provide first evidence that tactile suppression may indeed free capacities to process other, movement-relevant somatosensory signals. Moreover, the observed perceptual changes were associated with adjustments in the motor system suggesting a close coupling of predictive mechanisms in perception and action.
Meeting abstract presented at VSS 2018