Haptic Pursuit Tracking

Author:

Dawson, Amanda M

Graduate Program:

Psychology

Degree:

Doctor of Philosophy

Document Type:

Dissertation

Date of Defense:

August 24, 2006

Committee Members:

David A. Rosenbaum, Committee Chair/Co-Chair
Richard Alan Carlson, Committee Member
Peter Andrew Arnett, Committee Member
John Henry Challis, Committee Member

Keywords:

haptics
tracking
coordination
movement
bimanual
touch

Abstract:

This set of experiments show that in a novel task – bimanual haptic tracking – neurologically normal human adults can move their two hands independently for extended periods of time with little or no training. Participants lightly touched buttons whose positions were moved either quasi-randomly in the horizontal plane by one or two human drivers (Experiment 1) or in circle and square patterns in the vertical plane by two human drivers (Experiment 2), or at different frequencies in the horizontal plane by two human drivers (Experiment 3). Bimanual contact was maintained equally well in all conditions even though in Experiment 1 the left- and right-hand motions were uncorrelated in the 2-driver condition, and in Experiment 2 the left- and right-hand motions were spatially incongruous when circles and squares were tracked at the same time, and in Experiment 3 the left- and right-hand motions maintained different frequency ratios. Predictability of the position and velocity of a tracked stimulus was manipulated in Experiment 4 through the use of probabilistic abrupt direction reversals. Experiment 4 established that individuals did not benefit from predicting over the long-term either the position or velocity of a target they were haptically tracking. In Experiment 5, haptic tracking was studied in a context of a to-be-tracked stimulus momentarily disappearing by going behind an “occluder”. Experiment 5 provided some support for the retention of velocity information over time but not path, and, together with the Supplementary Experiment, established the critical role of discriminable shear forces and slip information for accurate haptic tracking.