Whether feeling or seeing is more accurate depends on tracking direction within the perception-action cycle.

Coordination in biological systems requires a continuous updating of the perception-action cycle. How the different sources of sensory information contribute uniquely to performance is still debated. Here, we directly compared the role of vision and kinesthesis by means of a tracking task in which the left wrist mimicked the passive motions imposed on the right wrist with a torque motor. The passive movements were perceived visually (alien hand) or kinesthetically (own hand), or a combination thereof (own hand, feel and see). Tracking occurred according to the same (isodirectional) or opposite (mirror-image) directions. Findings revealed that visual tracking was performed most successfully in the isodirectional and kinesthetic tracking in the mirror-image mode. Tracking was most successful when both sources of sensory information were present. These results suggest that vision and proprioception obey direction-dependent constraints that are consistent with extrinsic and intrinsic reference frames within which the perception-action cycle resides. Thus, each sensory modality contributes uniquely as a function of the spatial requirements of the tracking task, rather than one being superior over the other.