Tactile suppression during movement as optimal integration of somatosensory feedback across time

Abstract

Goal-directed movements generate tactile signals from the moving body, yet many are perceptually suppressed. Prevailing accounts propose that the nervous system reduces tactile sensitivity by prioritizing internal predictions over somatosensory feedback, contrasting with the view that suppression reflects peripheral masking. However, both accounts lack quantitative explanations of temporal dynamics and dependence on the motor task. Here, we show that tactile suppression is a consequence of optimal state estimation during movement. Using optimal feedback control theory, we derived how the nervous system should dynamically weight uncertain internal predictions against noisy somatosensory feedback. Human participants performed goal-directed reaching movements while vibrotactile stimuli were delivered at different time points. Suppression weakened as internal uncertainty about hand distance to target increased, consistent with greater reliance on sensory feedback. Model comparison identifies tactile suppression as dynamic, uncertainty-dependent state estimation rather than peripheral masking, establishing a normative principle for tactile sensitivity during action.