Abstract
Previous studies have investigated eye-hand coordination when tracking with the hand a pseudo-random target (Xia & Barnes, 1999; Soechting et al, 2010; Tramper & Gielen, 2011). In all these studies the mapping between hand motion and cursor motion was always straightforward. Here we investigate the impact of using a complex hand-cursor mapping. Two hand-cursor mappings were tested, either a simple one in which hand and cursor motion matched perfectly, or a complex one in which the cursor behaved as a mass attached to the hand by means a spring. Pseudo-random target motion was obtained via the combination of two sinusoids on each of the vertical and horizontal axis (Mrotek & Soechting, 2007). Subjects were instructed to move their hand so as to bring the animated cursor as close as possible from the moving target. Our results showed that hand tracking performance was substantially more accurate under the regular mapping that the spring one. On average the tracking error (i.e. cursor-target distance) was almost two times greater under the spring mapping (4.8 vs. 2.7cm). Although in the latter case hand tracking improved across trials, performance never returned to baseline (i.e. compared to regular). Despite those substantial differences in hand tracking performance, eye behaviour seemed relatively unaffected. Indeed under both types of mapping, gaze always led cursor position and lagged on target position, but with gaze remaining substantially closer from the target (about 2.5 cm) than from the cursor (up to 4.5 cm under spring). In addition, we found no difference in the saccade rate between the two mappings. Overall we conclude that 1) even when subjects have to learn a complex hand-cursor mapping, gaze is mostly driven to gather information about ongoing target motion, and 2) eye behaviour is relatively insensitive to hand-cursor mapping.
Meeting abstract presented at VSS 2017