Temporal Dynamics of Sensorimotor Integration for Non-Visual Target Information During Movement Preparation and Online Control

Endpoint movement variability in non-visual (auditory and proprioceptive) target reaching is modality-dependent. This study investigated whether such modality-specific effects may emerge during movement preparation and how they unfold during movement execution. Participants performed reaching movements toward auditory, proprioceptive, or audio-proprioceptive targets. Electromyography and movement kinematics were recorded to examine the effect of target-related sensory modality on sensory encoding and coordination of motor commands during movement preparation, as well as their effect on movement execution. Results revealed a modality-dependent sensory encoding phase, whereas a modality-independent coordination of motor commands. While the target modality did not affect movement initiation, it modulated the subsequent movement execution. These findings demonstrate that, in non-visual target reaching, the effect of target-related sensory modality extends beyond execution to specific phases of movement preparation. Our results support a four-stage model of action control toward non-visual targets, consisting of a modality-dependent sensory encoding phase of movement preparation and early execution, as well as a modality-independent motor coordination and movement initia-tion. These findings provide new insights into the temporal dynamics of sensorimotor control without vision, suggesting a different use of non-visual (proprioceptive and auditory) target-related sensory information during distinct phases of movement preparation and execution. HighlightsO_LIAuditory and proprioceptive target reaching shows modality-specific endpoint variability. C_LIO_LIThis study investigates whether such modulation occurs within the movement preparation stage. C_LIO_LIModality-specific sensory modulation has been found in specific phases of movement preparation. C_LIO_LIModality-specific effects emerge during early and late movement execution. C_LIO_LIFindings support a four-stage model of non-visual action control, separating encoding, coordination, initiation, and execution. C_LI