Fig. 4

Analysis of R² suggests spectral and spatial differences in EEG activity between conditions. (a) R² scalp topography plots during movement for two participants showing good (left, participant S005) and poor (right, participant S001) generalization across conditions. Consistencies in spatial and spectral activity across conditions resulted in better decoder generalization evidenced by higher AUCs. (b) Difference in R² during movement between conditions for one participant (left) and averaged across participants (right). Group analysis of R² differences between conditions revealed focused differences between cued movement and imagery, and widespread differences between cued and uncued movement. Significant channels were not corrected for multiple comparisons. (c) PCA projections of R² scalp topographies for all conditions and frequency bands. R² data across electrodes was projected onto the first three PCs. Each point represents one participant, and data is color-coded by condition. PCs across conditions (left and right columns) are the same. Conditions shown separately for visualization purposes. (d) Average Euclidean distance of imagery and uncued movement to cued movement in PC space. Distance between uncued and cued movement is slightly larger than the distance between imagery and cued movement, but this effect is not significant