Respecting the Coupled Dynamics: Haptic Feedback Carries both Power and Information

Haptic feedback provided in the axis of a motor task cannot be removed without changing the motor task itself. Haptic feedback couples the biomechanics of the backdrivable body to the dynamics of the environment and establishes a conduit for both power and information exchanges. To isolate the roles of haptic feedback in information exchange and power exchange, we devised a task without haptic feedback that preserved the motor challenge of controlling the coupled dynamics. We placed an identified model of a participant’s biomechanics in the virtual environment and coupled it to the original task dynamics. Visual feedback was provided to substitute for the missing haptic feedback. We compared the performance of N=5 participants in the same motor task with and without haptic feedback and in the new task without haptic feedback. The presence of the coupled dynamics in the task predicted the match across conditions rather than the feedback modality. Our results provide support to the idea that rather than controlling their environment, humans control the coupled dynamics of their body and environment.