This interaction, reflecting a top down mechanism exerted by parietal areas for the inhibition of visual cortices, was found to be related to behavioral performance and to indices of anatomical connectivity. Specifically, the hemispheric asymmetry of this occipito-parietal modulation of connectivity was predicted by the asymmetry in the volume of the first and the second tracts of the Superior Longitudinal Fasciculus and was positively correlated to the accuracy in performing the task. Additionally, the antisymmetric part of bicoherency revealed an increase in alpha-beta coupling, induced by the cue presentation, between the right FEF and parietal areas in both hemifields (Figure 10). No other frequency band was observed.
