Event-related cortical potentials occurring prior to speech initiation

Real time brain electrical potentials were obtained in subjects prior to the initiation of speech in a potential clinical paradigm using a single vertex electrode. The purpose of this research was to establish a real-time event related brain electrical potential system and to compare the results to offline responses. Research in this area in the past has used a great number of facial and lip EMG electrodes. The marking point for determining the pre-event time epoch has been an EMG source. The data are typically acquired off-line and later averaged. This research uses a vocal signal as the marking point, and displays in real time the event-related potential. A number of CV stimuli were used. The sample rate (25 600 samples/s) permitted an analysis of both slow negative waves and faster neurogenic signals. Results indicated reliable waveform morphology within and between subjects.