Somatosensory control of precision grip during un- predictable pulling loads: 11. Changes in load force rate

Summary. In manipulating 'passive ' objects, for which the physical properties are stable and therefore predictable, information essential for the adaptation of the motor output to the properties of the current object is principally based on 'anticipatory parameter control ' using sensori-motor memories, i.e., an internal representation of the object's properties based on previous manipulative experi-ences. Somatosensory afferent signals only intervene inter-mittently according to an 'event driven ' control policy. The present study is the first in a series concerning the control of precision grip when manipulating 'active ' ob-jects that exert unpredictable forces which cannot be adequately represented in a sensorimotor memory. Con-sequently, the manipulation may be more reliant on a moment-to-moment sensory control. Subjects who wer