Movement planning predictions shape somatosensory sensitivity
Tactile sensitivity is reduced during limb movement, a phenomenon known as somatosensory gating. Here, across two experiments, we ask whether gating is driven by motor prediction or by motor execution. In a Go/NoGo paradigm, in which participants planned movements in every trial but on rare trials had to withhold them. Since previous work indicated that predictions about movement kinematics influence gating also during passive movements, we also tested a mechanical arm transport in a passive Go/NoGo paradigm. Perceived intensity was attenuated exclusively on Go trials, in both active and passive movements, and was indistinguishable from baseline on NoGo trials. However, discrimination precision was selectively degraded in Active NoGo trials when a movement was planned and then withheld. In Experiment 2, vibro-tactile probes delivered before movement onset already showed the same bias as probes delivered during movement, in both active and passive conditions, while precision remained unchanged. Our data demonstrates that the sensorimotor system predictively establishes tactile precision before movement onset. Such a mechanism might contribute to active texture exploration by separating tactile signals from the sensory signals arising through the self-produced movement.