Abstract
Hand deviations toward or away from distracting objects have been well observed, but much of the research has focused on pointing rather than grasping movements. During grasping, the palm must reach and make contact with the object, suggesting that objects on the palm side may have larger distractor effects. This study contrasts the effect of distractors located palmward or dorsal to the hand in a reach-to-grasp task. We hypothesized that palmward distractors would exert greater interference on reach trajectory than dorsal distractors, indicating a prioritization for palmward objects. The second objective was to examine if this bias differed when participants used the back of their hand to respond. In a 2x2 within-subjects design, participants made left- or right-handed reaches to tip over a target object presented alongside a distractor, using either the palm or back of their hand. Results showed larger interference effects with palmward distractors, particularly when using the palm side for the response. This suggests a processing bias for palmward objects, and that the impact of this bias depends partly on the palm’s role as the effector.
