Vowel Imagery Decoding toward Silent Speech BCI Using Extreme Learning Machine with Electroencephalogram

Figure 1

Schematic sequence of the experimental paradigm. Vowels /a/, /e/, /i/, /o/, /u/, and mute were randomly presented 1 s after the beginning of each trial. After the third beep sound, the subject imagines the same vowel heard at the beginning of the trial. The EEG data acquired during the speech imagination period were used for signal processing and classification in this study.