Abstract
Can perceptual organization affect the spontaneous allocation of attention? Namely, when some elements in the visual display that do not have any unique property (including abrupt onset or other unique transients) are organized into an object, is visual attention spontaneously drawn to the object? We addressed this question using a modification of a paradigm originally developed by Logan (1995). Observers were presented with a display of nine L's, one of which was the target. The target was red or green; four of the distractors were red and four were green. The L's were rotated at different angles and positioned at the vertices of four adjacent “diamonds” that made up a global “diamond”. Observers had to report the color of the target. An asterisk was presented in the center of one of the quadrants. The target display was preceded by an instruction display containing a word -up, down, left, or right- that specified the relation between the asterisk and the target. Hence, if the word was ‘above’ observers had to identify the color of the L above the asterisk. On half the trials, the four L's of one of the quadrants were collinear and thus formed a local diamond — an object. The asterisk appeared in this object-quadrant on 25% of the trials. There were three conditions: Object — the asterisk appeared in the object-quadrant; Neutral — no object was formed in any quadrant; No Object — the asterisk appeared in a non-object quadrant but an object was present in another quadrant. The SOA between the target display and the asterisk varied (0 — 500 ms). We found that performance was faster in the Object condition than in the Neutral condition (a benefit) and slower in the No Object condition than in the Neutral condition (a cost), with the cost manifesting at shorter SOAs than the benefit. These results suggest that a perceptual object attracts attention spontaneously, even when there is no abrupt onset or other unique transients.