Figure 3.

(A) Synchrony between frontal and parietal cortex during visual pop-out (top) and visual search (bottom) Both tasks emphasize a “beta” band (18–34 Hz) and a “gamma” band (35–55 Hz) over baseline. However, there is a greater emphasis on gamma band activity during pop-out and beta band during search. (B) Direct comparison of synchrony between frontal and parietal cortex across frequency. This comparison highlights the increase in synchrony between frontal and parietal cortex in the beta band during top-down, internally guided visual search. Likewise, an increase in gamma band synchrony is observed during bottom-up, externally driven pop-out.