Correlations between EEG and HbO2 for all subjects.

For each subject 100 s windows, which exhibit significant correlation (r>0.3), and their corresponding delays, are listed in the 9–14 and 15–25 Hz frequency bands. In the last column the delays with the largest correlation are indicated. For subject’s S2 and S5 the second largest correlations are also marked. Mean delay ( SD) is calculated without subject’s S2 and S5. Subjects with a high coupling ( between HbO2 and BP are highlighted in grey.