Distracter effects on pointing: the role of spatial layout

There is a debate about how task-irrelevant visual distracters influence mo tor responses. Inconsistent findings in previous studies may reflect the us e of different spatial layouts. In this study. participants pointed to rand omly lateralized targets under full viewing conditions, either with or with out a Single distracter present. Distracter location, size, and spacing fro m the target were systematically manipulated while target size and movement amplitude remained constant. Larger distracters facilitated reaction times and slowed movement times. Distant distracters facilitated only reaction t imes. Movement endpoints were biased away from distracters. The single dist racter also modulated perceived target size. These results are discussed in the context of current theories of the role of visual perception for actio n control.