Assessing the Minimum Number of Synchronization Triggers Necessary for Temporal Variance Compensation in Commercial Electroencephalography (EEG) Systems

This technical note describes the differences in recording when events happen between several commercially-oriented electroencephalography (EEG) recording systems. The four systems examined, Emotiv's EPOC, Biosemi's ActiveTwo, Advanced Brain Monitoring's B-Alert X10 and Quasar's prototype represent different approaches to the problem of recording brain activity in human subjects. We found that the EPOC introduces significantly more error in recording event timing, though this issue is present in all systems. Furthermore, we demonstrate with iterative linear regressions that the number of calibration pulses required to properly estimate timing error is system dependent. Therefore, any new EEG acquisition systems must be tested independently.