Unconscious updating of grasp motor program.

摘要: Grasp modification during prehension movements was studied in response to slight variations of somesthetic information about object size. Three experiments were carried out. In experiment 1 eight subjects required reach and grasp an whose size could either increase or decrease, whereas its visual image remained unmodified. The changed the with uninformed after a block trials which congruent. At end reproduce their fingers (matching test). Results showed that maximal grip aperture as well finger matching test modified according variation size, although no subject realized had experiment. time also altered by change. Greater earlier adaptation aperture, perturbation time, observed for decrease than However, complete compensation never reached both parameters. Constant confidence vision have prevented conscious detection This investigated two additional experiments. 2 made unreliable informing grasped led greater 1. kept almost constant regardless variation. 3 stimulus on change given subjects. results similar those 1, larger Correspondingly, more affected three suggest kinematic parameters usually considered dependent properties, such order compensate temporal induced "pragmatic" knowledge (as test), awareness not reached.