Grasp strategy when experiencing hands of various size

An objective evaluation of a system that provides the experience of hands of different sizes is performed from the viewpoint of the change in grasping pattern. The hand size is recognized as being different from that of the subject´s actual hand (normal hand) when the hands of various sizes are presented in an environment that appears to be of constant size. This is achieved by viewing a hand and an analogous object through an optical system that adjusts its scaling rate to visually maintain the object size. An objective evaluation of this system is performed by investigating the grasp strategy depending on the hand size and object size reported in T. Shirai et al. (1998). The experimental results reveal that a similar grasp strategy that depends on hand size is observed for the proposed system based on the presented hand size. In addition, the experimental results reveal that it is important to vary the hand and object sizes visually through an optical system rather than simply using analogous objects without visual scaling.