Figure 4

Checkerboard oddball paradigm. Rare checkerboards with coarse check sizes are randomly interspersed with frequent checkerboards with fine check sizes (top row, condition FF) and vice versa (bottom-row, condition CF). Participants were instructed to count the occurrences of the rare checkerboards within an experimental block. Each checkerboard (coarse or fine) was presented for 500 ms and alternated with a gray screen interval, which was also present for 500 ms.