Figure 2

SL connectivity between and within ROIs. (a) ROC curve value for all frequency bands, between and within frontal and occipital ROIs. Fronto-occipital SL connectivity produced ROC curves showing significant P-values for the delta, theta, beta and gamma bands. See Additional file 2: Table S2 for all A_ROC values. (b) ROC curve value for all frequency bands, between and within right and left ROIs. Left-right SL connectivity produced ROC curves showing significant P-values for the delta and theta bands. See Additional file 4: Table S3 for all A_ROC values. (c) ROC curves after performing a median-split group separation, classifying subjects as high or low SRS score according to their gamma band SL value. Only the fronto-occipital SL shows significant classification (A_{ROC fronto-occipital} = 0.86; A_{ROC occipital} = 0.51; A_{ROC frontal} = 0.59). (d) Multivariate regressions obtained by averaging all gamma band SL values within (frontal and occipital) and between (fronto-occipital) ROIs, against SRS score (and gender and age as other regressors). Frontal and occipital SLs do not show significant regression with SRS score (occipital: P = 0.23, R-square = 0.01; frontal: P = 0.31, R-square = 0.001). The fronto-occipital SL, in contrast, does show good regression between SL and SRS score (P < 0.05, R-square = 0.09).