Figure 4.

Coupling between BOLD and alpha within the IPS. (A) Cluster sizes in left and right IPS showing significant inverse coupling with contra- and ipsilateral alpha collapsed across attend-left and attend-right conditions. The mean and standard error in cluster size were obtained by bootstrapping 500 times on the group level. (B) Coupling strength between BOLD and alpha within the IPS clusters for contralateral and ipsilateral alpha, respectively. A significantly stronger inverse coupling was observed in left IPS for contralateral alpha compared with ipsilateral alpha. Error bars represent standard error of mean on the group level. Here the coupling strength is measured by the coefficient in front of the regressor representing contralateral or ipsilateral alpha power collapsed across attend-right and attend-left conditions.