Fig. 6: Offline decoding performance and electrophysiological analysis.
From: EEG-based brain-computer interface enables real-time robotic hand control at individual finger level
Group-level offline decoding performance of finger ME (A) and MI (B) using EEGNet and FBCSP (n = 21 subjects), where 1 represents thumb, 2 represents index finger, 3 represents middle finger, and 4 refers to pinky. The red dashed lines indicate the chance levels. The center lines indicate the median values. The boxes extend from the lower quartile to the upper quartile. The whiskers span up to 1.5 times the interquartile range. Comparisons between two decoders were conducted using a two-tailed Wilcoxon signed-rank test with Bonferroni correction for multiple comparisons. P-values: 0.0011 (A, 1-2), 0.0003 (A, 1-3), 0.0006 (A, 1-4), 0.0132 (A, 2-3), 0.0308 (A, 2-4), 0.0009 (A, 3-4), 3.81e−06 (A, 1-2-3), 0.0011 (A, 1-2-4), 0.0002 (A, 1-3-4), 2.67e-05 (A, 2-3-4), 3.81e-06 (A, 1-2-3-4), 0.0054 (B, 1-2), 0.0001 (B, 1-3), 5.72e−06 (B, 1-4), 0.0009 (B, 2-3), 0.0011 (B, 2-4), 1.14e−05 (B, 3-4), 0.0003 (B, 1-2-3), 0.0002 (B, 1-2-4), 1.14e-05 (B, 1-3-4), 0.0005 (B, 2-3-4), 0.0002 (B, 1-2-3-4). Group-level task-specific alpha band (8−13 Hz) (C) and beta band (13–30 Hz) (D) ERD topographies (n = 21 subjects). From left to right, ERD topographies corresponding to thumb, index, middle, and pinky movements are displayed. The top row presents results from ME data, while the bottom row presents results from MI data. Comparison of offline EEGNet decoding performance (n = 21 subjects) for ME (E) and MI (F) tasks using EEG signals filtered with different bandpass settings (4–40 Hz, alpha band, beta band, delta band, theta band). The x-axis shows classification results for different frequency bands. Offline classifications were performed on thumb vs. pinky (1-4), thumb vs. index finger vs. pinky (1-2-4), and all four fingers (1-2-3-4). Two-way ANOVA was conducted across different frequency bands and finger pairs, and statistical significance was observed in all task conditions. Significance stars indicate post hoc pairwise comparison results using an FDR-corrected two-tailed Wilcoxon signed-rank test (*** if p < 0.001, ** if p < 0.01, * if p < 0.05). P-values: 0.0181 (E, 4–40 Hz vs. Alpha), 9.53e−06 (E, 4–40 Hz vs. Beta), 4.45e−05 (E, 4–40 Hz vs. Delta), 4.45e−05 (E, 4–40 Hz vs. Theta), 0.0018 (E, Alpha vs. Beta), 0.0020 (E, Alpha vs. Delta), 0.0023 (E, Alpha vs. Theta), 0.0197 (E, Beta vs. Delta), 0.0329 (F, 4–40 Hz vs. Alpha), 3.17e−06 (F, 4–40 Hz vs. Beta), 3.17e−06 (F, 4–40 Hz vs. Delta), 1.19e−05 (F, 4–40 Hz vs. Theta), 0.0002 (F, Alpha vs. Beta), 3.17e−06 (F, Alpha vs. Delta), 4.76e−05 (F, Alpha vs. Theta), 8.74e−05 (F, Beta vs. Delta).
