Multiple-object tracking and visually guided touch

Multiple-object tracking (MOT) involves keeping track of the positions multiple independent target items as they move among distractors. According to Pylyshyn (Cognition, 80, 127–158, 2001), item individuation mechanism used in MOT is also visually guided touch. To test this, we compared single-task (MOT alone) with dual-task while touching that changed colour), looking for interference: cases where performance was worse than dual-task. Touching colour interfered MOT, but effects varied depending on whether touched a or distractor MOT. distractors always reduced more targets. targets during did not interfere when there only single once were two We measured interference based latencies touch colour, comparing and conditions (touch alone, + track). touch, increasing RT significantly higher those rather Overall, general (differences between performance), might be expected if coordinating tasks required common limited resource such attention working memory. However, differential This suggests specific mechanisms may play role