Abstract
In one foundational study of action-centred attention (Tipper et al. 1992), two patterns of distractor interference were reported: the ipsilateral effect - distractors on the same side of space as the effector caused more interference than distractors in the opposite side of space; and, the proximity effect - distractors closer to effector cause more interference than farther distractors. These patterns of interference are thought to emerge because distractors ipsilateral and closer to the effector activate salient competing responses and require more time to inhibit. One aspect that has not been addressed is how interference emerges when individuals need to choose responses between the hands. We hypothesized that distractors which activate responses for the other limb may cause greater interference than distractors that alter the movement specifications within a limb. This prediction is based on research showing that the specification of the arm occurs before the specification of movement direction and amplitude (Rosenbaum, 1980). Participants in the present study executed reaching movements to 1 of 4 (2 left, 2 right) possible target locations with and without a distractor. In Experiment 1, participants made ipsilateral reaches (left hand to left targets, right hand to right targets). In contrast to studies using one-handed reaches, a "contralateral effect" was observed in which distractors affording responses for the other hand caused more interference than distractors affording responses for the same hand. In Experiment 2 (a control study similar to Tipper et al., 1992), participants used their right hand to reach to all targets. Contrary to Experiment 1, a contralateral distractor interference effect was not observed. Together, the findings from the present research support the notion that attention is influenced by the actions being performed and, further, support Rosenbaum’s idea that the specification of the effector occurs earliest in motor planning.
Meeting abstract presented at VSS 2012