Surface Potential Phase Discrimination of Bereitschaftspotentials

The performance of single-trial classification of the movement-related cortical potential (MRCP) must be improved to be valuable in realistic brain-computer interface (BCI) applications. There is evidence to suggest that the assumption of non-interaction between slow cortical potential (SCP) activity and MRCPs may be limiting this performance. We hypothesized that the magnitude of MRCP peak activity is modulated by the phase state of lower frequency slow cortical potentials (SCP). MRCPs of 6 subjects were separated according to change in phase of SCP 0.11-0.31 Hz activity 4 seconds prior to MRCP peaks. It was found that, for five of six subjects, MRCPs associated with greater pre-event SCP phase change also had larger peak negativities and movement monitoring potentials (MMP).