Image orientation and contents influence pointing movements on touch sensitive screens: a kinematic analysis

Given the increasing use of touch-screens, the impact of images of objects upon cursor positioning were examined. As objects may present compatible and conflicting cues for movement, we examined the influence of relevant and irrelevant cues on responses when pointing to images on touch-screens. An experiment (N = 24) examined leftwards or rightwards pointing movements to images of large or small cups with handles that could be compatible or incompatible for grasping and were depicted as full or empty. Handle compatibility only benefited response latencies for empty cups, and this effect was reversed for small cups. Kinematic analyses suggested movements were less efficient to images of cups with compatible handles. Aiming points varied with cup size and contents suggesting that handles influenced performance when they presented lower Indices of Difficulty (as per Fitts' law). Object characteristics can influence screen hot-spots, and this primarily occurs whilst the cursor is in motion.