Role of cutaneous and proprioceptive components in object manipulation tasks

Abstract Proprioceptive and cutaneous components allow us to have information of the manipulated object. Both components were characterized independently in object manipulation tasks, but their coordination is not well known. Here, this question is handled to know how both feedback coordinate by analyzing the activity of the FDI (first dorsal interosseous) and FDS (flexor digitorium superficialis) muscles when the finger is subject to an external perturbation. Its was found that the propriocetive feedback influence only the FDI muscle, where an ”automatic gain-scaling”, a phenomenon that is characterized by a scaling of the EMG response depending on the background activity, was observed when the FDI muscle was stretched. This phenomenon was not observed in the FDS muscle and, in addition, the response of the FDS occurred always after ∼90 ms following the perturbation onset, independent of the direction and amount of finger motion. This suggests that the FDS muscle may react thanks to the cutaneous component. These results suggest that different sensorimotor functions are maybe en- gaged by both components in order to active these two muscles.