Figure 3

Topology of networks obtained from delta band SL _f,p matrices. (a) Small-world indices, after a median-split of subjects into high and low SRS groups. Low SRS subjects have a higher small-world index (low SRS group = 0.38, high SRS group = 0.22; T-value = 4.17; P = 0.0001; see Additional file 4: Table S3 for the size effect of all frequency bands). (b) ROC curve for the discrimination between low and high SRS score based on the small-world index. A_ROC is highly significant (A_ROC = 0.74, P < 0.001). (c) Regression between small-world index and SRS score (and age and gender), showing the negative relation between small-world index and SRS score (β-value = -0.08; P = 0.008, R-square = 0.09).