Multichannel Phase Synchrony Analysis in SSVEP-based BCIs

Danhua Zhu , Gary Garcia Molina, Vojkan Mihajlovic, Shirin Abtahi, Ronald M. Aarts 2 E-mail: zhu.danhua@philips.com Technical University Eindhoven, Netherlands; Philips Research Europe, Eindhoven, Netherlands INTRODUCTION Brain computer interfaces (BCIs) based on the steady state visual evoked potential (SSVEP) can provide higher information throughput as compared to other BCIs. Using a high frequency (in the range of 30 to 40 Hz) repetitive visual stimulus to elicit SSVEP is safer and more comfortable for the user. However, only few frequencies in this range can elicit a sufficiently strong SSVEP for BCI purposes. This limits the number of possible commands that can be executed and consequently the bitrate. In order to circumvent this limitation, we propose to use multiple oscillatory stimuli sharing the same frequency but with a different phase.