Figure 1.

(A) The experimental paradigm. Trials were subject-initiated and began with a fixation spot (300 ms), followed by a stimulus (120 ms), followed by a random mask (500 ms). (B) Example stimuli. Stimuli consisted of a 64 × 64 array of checks, in which a 16 × 64 target region is positioned eight checks from one of the four edges of the array. Stimuli were of two types: left, the background is random, and the target is structured (here, θ_⌋ = 1), or right, the background is structured and the target is random. The red rectangles indicate the location of the target and were not visible during the trials.