Neural Changes in Processing Visuo-Tactile Looming Stimuli Following Hand-to-Foot Sensorimotor Remapping

Abstract

Interactions with the environment follow stable spatial regularities that allow the brain to predict where sensory events are likely to occur. Although these expectations can adapt when actions repeatedly produce altered sensory consequences, whether spatial regularities learned through action influence subsequent sensory processing in the absence of action remains unclear. Participants underwent virtual reality (VR) sensorimotor remapping training in which right-hand interactions produced tactile feedback on either the ipsilateral (n=23) or contralateral foot (n=23). Feedback was either synchronous with hand object contact, establishing a reliable action sensation relationship, or asynchronous, providing comparable tactile exposure without a consistent temporal contingency. Before and after training, EEG was recorded during a visuo-tactile looming task in which participants passively observed objects approaching the hand while tactile stimulation was delivered to the hand (expected) or occasionally to the foot (unexpected). We examined the mismatch negativity (MMN) and P300 to determine whether the learned hand-to-foot regularity influenced subsequent processing of these events. P300 responses to hand stimulation increased selectively following synchronous training, indicating that learning a reliable hand-to-foot relationship altered subsequent processing of hand-related events outside the action context. In contrast, neither MMN nor P300 responses to foot stimulation differed between synchronous and asynchronous training, providing no evidence for direct transfer of the newly learned spatial mapping. Relative to baseline, foot-related responses instead showed contingency independent changes consistent with more general exposure related adaptation. Together, these findings show that spatial regularities learned through action can influence subsequent sensory processing beyond the context in which they are acquired, while highlighting constraints on their generalization across active and passive interactions.