PLANNING MACROSCOPIC ASPECTS OF MANUAL CONTROL

Although considerable attention has been paid to detailed features of motor performance, surprisingly little attention has been paid to the selection of macroscopic features. This paper is concerned with the se lection of one such feature - whether to pick up a stick with the thum b pointed toward one end or the other when the stick is to be brought to some other location. The choice of hand orientation is found to dep end on how comfortable the arm will be at the end of the bar-transport movement. In addition, the choice of hand grip depends on which hand grips were used before. The sequential effect suggests that there is a cost in selecting macroscopic movement features which can be offset b y continuing with the existing strategy until feedback indicates that a change is required.