Attentional guidance in visual attention

Earlier research has shown that a task-irrelevant sudden onset of an object will capture or draw an observer's visual attention to that object's location (e.g., Yantis & Jonides, 1984). In the four experiments reported here, we explore the question of whether task-irrelevant properties other than sudden-onset may capture attention. Our results suggest that a uniquely colored or luminous objects, as well as an irrelevant boundary, may indeed capture or guide attention, though apparently to a lesser degree than a sudden onset: it appears that the degree of attentional capture is dependent on the relative salience of the varied, irrelevant dimension.