ABSTRACT
A number of previous studies have shown that during the preparation of a goal-directed movement, perceptual selection (i.e. visual attention) and action selection (the selection of the movement target) are closely related. In four experiments, we studied attentional selection in movement situations in which more than just a single movement target had to be considered. In all four experiments, a dual-task paradigm was used that combined a perceptual discrimination task with movement preparation (Deubel & Schneider, 1996). In Experiment 1, we studied attentional deployment in a task that required the participant to perform a sequence of two subsequent movements to two targets. The results suggest that visual attention is not only allocated to the first but also to the second movement target even before the onset of the initial movement. The results of Experiment 2 demonstrated that not just the movement goal but also an obstacle is selectively processed when it is part of the movement plan. In Experiments 3 and 4, participants had to grasp a cross-like object with thumb and index finger. The experimental results reveal that visual attention is largely confined to the action-relevant parts of the object-that is, those parts that will be grasped. Together the findings demonstrate that attention is basic to sensorimotor processing and that our dual-task paradigm is well suited for unveiling covert sensorimotor selection processes that occur before complex open movements.
