Figure 2.

Trial structure for training and testing paradigm and process of mode-alternating. (A) Trial procedure of a training and testing phase according to the cue presented in the screen or emitted from the computer. The time ranges of EOG, EEG and EMG mode are from 0 to t1, from t2 to t3, and from t4 to t5, respectively. The time ranges for mode-alternating separately are from t1 to t2, from t3 to t4, and from t5 to t6. (B) The mode-alternating circular ring describes the mode-alternating process of the three modes according to subject's intention from double blink.