Figure 1.
Stimulus configurations in experiment 1 for the IO and FO conditions. In the IO condition, a single square was continuously present on the display. Subjects were cued to covertly attend to the visual quadrant (UL in the example shown) indicated by a pair of arrows directly above or below fixation. Stimuli consisted of brief (100 ms) offsets of the four corners of one of the squares. The offset stimuli left either a concave (standard) or convex (target) edge. Dotted lines outlining the attended quadrant were not present in the display. The FO configuration was identical, except that the square was divided into four uneven sections that together comprised the same area as the single square. In both cases, object-selective attention effects were analyzed by comparing the ERPs and fMRI signal elicited by unattended corner offsets as a function of whether these formed part of the same cued object (IO condition) or belonged to a different, unconnected object (FO condition).
