Oculomotor capture by abrupt onsets reveals concurrent programming of voluntary and involuntary saccades

Abstract

In several recent experiments we have found that the eyes are often captured by the appearance of a sudden onset in a display, even though subjects intend to move their eyes elsewhere. Very brief fixations are made on the abrupt onset before the eyes complete their intended movement to the previously defined target. These results indicate concurrent programming of a voluntary saccade to the defined saccade target and an involuntary saccade to the sudden onset. This is inconsistent with the idea that a single salience map determines the location of a saccade in a winner-take-all fashion. Other results indicate that subjects attend to more than one location in a display during saccade preparation, contrary to the claim that covert attentional scanning plays no role in saccade generation.