A heuristic to capture multi-directional lateral tactile perception

Multi-directional tactile perception adds significant complexity when interpreting haptic experimental data. In perceiving tactile stimulus direction, we often observe a lack of one-to-one stimulus-response compatibility, mostly due to confounding sensations that reinforce and/or distort a primary stimulus. This study presents the development of a metric to capture multi-directional lateral tactile perception on a finger pad. Sixty-two subjects rated the direction and magnitude of lateral motion from a single probe moving in one of the eight possible directions. A heuristic based on a vector matrix was developed to capture and integrate the relative contribution of each subject's rated directional perception in x–y coordinates. This article explains the theoretical underpinnings and the justifications for this heuristic and highlights the usefulness of this approach for future haptic system designs.