How Many EEG Channels Are Optimal for a Motor Imagery Based BCI for Stroke Rehabilitation?

Abstract

The optimal number of EEG channels is a controversial issue for motor imagery based BCIs for stroke rehabilitation. In this study, we compared the BCI performance with 63, 27 and 16 channels of EEG on three stroke patients across 10 to 24 sessions, and demonstrated that the 16 channels montage yields similar classification error (21.3, ±, 11.6, 10.5, ±, 6.6 and 16.0, ±, 12.6, % for these patients respectively) to montages with larger number of channels. This is important for practical applications in stroke rehabilitation, since fewer channels means lower cost, less preparation time and easier maintenance.