Externally Generated Motion Elicits Predictive Motor Responses

Motor control is widely considered a predictive process in which the brain anticipates the sensory consequences of actions using internal forward models. These predictive mechanisms are typically studied in the context of voluntary movements, in which motor commands elicit expected sensory feedback. However, it remains unclear whether similar predictive motor responses can also be elicited when motion is externally generated and not initiated by the individual. The present study investigated whether externally generated relative motion can induce predictive compensatory motor responses in the absence of voluntary motor commands. Participants were exposed to externally driven motion that produced relative displacement between the body and a reference object. Motor responses were recorded to examine whether systematic compensatory adjustments occurred in response to the externally generated motion. The results revealed consistent motor responses that compensated for the externally induced displacement. These responses exhibited characteristics resembling predictive adjustments observed during voluntary movement control. The findings suggest that predictive motor mechanisms may be engaged not only during self-generated actions but also during externally imposed motion. These results indicate that predictive processes in motor control may operate more broadly than previously assumed, extending beyond voluntary motor commands to situations involving externally generated motion. This study provides new insights into the flexibility of predictive mechanisms underlying sensorimotor control.