Figure 1.
Average relative power of EEG signals (delta, 0.5–4 Hz; theta, 4–8 Hz; alpha, 8–13 Hz; beta, 13–30 Hz; and gamma, 30–50 Hz) from all HCs and patients with MDD in the OE (A) and CE (B) condition. White circles denote significant differences between groups (P < 0.05). CE, eyes-closed; EEG, electroencephalogram; HCs, healthy controls; MDD, major depressive disorder; OE, eyes-open.
Figure 2.
Average power asymmetry of relative activity between the pairs of electrodes (i.e., right location–left location) in HCs and patients with MDD in the OE (A) and CE (B) condition. HCs, healthy controls; MDD, major depressive disorder; CE, eyes-closed; OE, eyes-open.
Figure 3.
Grand functional connection maps of the left–right coherence between the pairs of electrodes at the threshold of 0.6 for different frequency bands during the OE (A) and CE (B) conditions. Red lines in the bottom panels denote significant differences between groups (P < 0.05). CE, eyes-closed; OE, eyes-open.
Figure 4.
Grand average of parameters, namely, strength, CC, and L, calculated from the delta, theta, alpha, beta, and gamma bands during the OE and CE conditions. *indicates significant differences between groups (P < 0.05). CC, clustering coefficient; CE, eyes-closed; OE, eyes-open.
Figure 5.
Average SampEn for the different frequency bands from all HCs and patients with MDD in the OE (A) and CE (B) conditions. White circles denote significant differences between groups (P < 0.05). CE, eyes-closed; HCs, healthy controls; MDD, major depressive disorder; OE, eyes-open; SampEn, sample entropy.
Figure 6.
Average MSE for the different frequency bands from all HCs and patients with MDD in the OE (A) and CE (B) conditions. White circles denote significant between-group differences (P < 0.05). CE, eyes-closed; HCs, healthy controls; MDD, major depressive disorder; MSE, multiscale entropy; OE, eyes-open.
Figure 7.
Average DFA for the different frequency bands from all HCs and patients with MDD in the OE (A) and CE (B) conditions. White circles denote significant differences between groups (P < 0.05). CE, eyes-closed; DFA, detrended fluctuation analysis; HCs, healthy controls; MDD, major depressive disorder; OE, eyes-open.
Table 1.
Average accuracy, sensitivity, and specificity of the SVM models for the selected features
| Training | Testing | ||||
|---|---|---|---|---|---|
| Eye-open | 181 | 95.26 ± 3.30 | 96.66 ± 5.80 | 95.93 ± 8.54 | 97.55 ± 8.86 |
| 17 | 84.99 ± 3.73 | 85.55 ± 10.99 | 87.76 ± 15.287 | 84.07 ± 18.83 | |
| Eye-closed | 293 | 91.00 ± 3.97 | 90.77 ± 8.51 | 91.38 ± 13.06 | 89.11 ± 15.52 |
| 9 | 87.65 ± 4.04 | 86.88 ± 10.03 | 87.73 ± 14.43 | 86.76 ± 17.44 |