Integration of Kinesthetic and Tactile Information for Manipulation and Grip Force Control During Force-Field Adaptation

When manipulating objects, our sensorimotor system integrates information from multiple sensory streams. An important stream is the force information that is sensed by two modalities in our body – kinesthetic and tactile. In this study, we examined the integration between kinesthetic and tactile information during adaptation to a force perturbation. We exposed participants who performed reaching movements toward targets to a velocity-dependent force field. For one of the groups, we added artificial tactile stimulation by stretching the skin of their fingertips in the same direction of the applied force. We found no difference between the kinematics of two groups, but the skin-stretch affected their manipulation and grip forces. These results suggest that tactile and kinesthetic information may have distinct mechanisms of integration with kinematic states during force field adaptation.