The Control and Perception of Finger Forces

The human hand demonstrates remarkable dexterity in its capacity to control precisely the forces involved in manipulating objects and the timing of movements during the execution of skilled motor tasks. In all of these endeavors, mechanoreceptors in the skin play a critical role in encoding the timing, magnitude, direction and spatial distribution of fingertip forces. When cutaneous inputs are absent or deficient, the hand is unable to compensate rapidly when an object begins to slip between the digits, and misdirected finger movements are not recognized and corrected. The control and perception of forces generated by the hand therefore relies on a close interplay between the sensory and motor systems. When sensory information changes, the capacity to control and modulate force can be disrupted and this in turn influences the perceived magnitude of the forces being produced. Cutaneous mechanoreceptors provide crucial information about the forces produced by the fingers and these inputs together with centrally generated corollary discharges are fundamental to the human perception of force.