Seeing while acting: hand movements can modulate attentional capture by motion onset.

The onset of new motion has been shown to be a very robust cause of attentional capture, generating a processing advantage for the location of motion onset regardless of the observer's concurrent goal. The present study, motivated by the common-coding account of action and perception, examined whether the effect of motion onset on visual attention can be modulated by the observer's mode of action. Specifically, the common-coding account predicts that preparing an action can render the features that are used in the action plan less available for visual processes. Consistent with this hypothesis, in Experiment 1 the magnitude of attentional capture caused by a single motion onset was reduced when this motion was similar to the observer's response (i.e., along the same axis). Similarly, in Experiment 2 the onset of a response-different motion gained a processing advantage over the response-similar motion onset when the two were presented simultaneously. Since both types of motion were present in every trial, the results of Experiment 2 suggest that response similarity affected visual-attentional processes rather than motor processes. Together, these results suggest that the processes of attentional prioritization caused by motion onset can be modulated by the observer's concurrent action.