EFFORTFUL TOUCH WITH MINIMUM MOVEMENT - REVISITED

The ecological static moment-torque model proposed by C. Carello, P. F itzpatrick, I. Domaniewicz, T. C. Chan, and M. T. Turvey (1992) does n ot uniquely explain the perception of rod length by static holding. Gu ided by a mechanical analysis of the gravitational forces and torques produced in the hand as it statically holds rods of different lengths and materials at different orientations, we offer 2 additional theoret ical explanations, the force-torque and weight-percept models. Experim ent 1 demonstrates that all 3 models predict perceived rod length with considerable success. Experiment 2 provides clear experimental suppor t for the force-torque and weight-percept models over the static momen t-torque model. Experiment 3 pits the former 2 models against each oth er. Current results favor the weight-percept model. Implications for t heories of haptic weight perception and design of a new tactile sensor are also considered.