Role of the inertia tensor in haptically perceiving where an object is grasped.
When an object is held and wielded, a time-invariant quantity of the wielding dynamics is the inertia tensor Iij. Examination of Iij as a function of different locations at which a cylindrical object is grasped revealed that the off-diagonal components of Iij--the products of inertia--related most systematically to grip position. In 3 experiments, Ss wielded an occluded rod held at an intermediate point along its length and reproduced, with the other hand, the felt grip position on a visible rod. In Experiment 1, the wielded rods were homogeneous; in Experiments 2 and 3, weights were added on either side of the grasp, with different manners of grasp contrasted in Experiment 3. In all 3 experiments, perceived hand position was predicted by Iij. Discussion was focused on the role of Iij's eigenvalues in perceiving the magnitudes of objects and Iij's eigenvectors in perceiving hand-object relations (e.g., position of grasp).
Pagano
C C
CC
Center for the Ecological Study of Perception and Action, University of Connecticut, Storrs 06269-1020.
Kinsella-Shaw
J M
JM
Cassidy
P E
PE
Turvey
M T
MT
D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D011603:Psychophysiology; D013236:Stereognosis / Q000502:physiology*; D014892:Weight Perception / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology