Fig. 4

Results of the topographical and frequency analysis. A, B Results from 2019. C, D Results from 2020. A and C Topographical maps of cortical areas providing the highest level of contribution for 2-class classification are indicated in red, separately, for LR, FR, LF, and TX classifiers in the three most prominent (12–18 Hz, 18–28 Hz, 28–40 Hz) frequency bands. B and D Time-varying frequency maps indicating frequency range providing the highest level of contribution for 2-class classification are indicated in red, separately, for LR, FR, LF, and TX classifiers. The rectangles in the A and C panels highlight topographical maps that belong to the most prominent frequency range (indicated with ellipses in the B and D panels)