Lecture by Stefan Debener: Towards transparent EEG

Most technologies for the non-invasive recording of human brain activity do not tolerate motion during signal acquisition very well. This poses an obvious dilemma to the field of behavioural brain sciences. Moreover, recently developed EEG systems are still too big to be used in daily-life situations. A transparent EEG, on the other hand, would not only be portable and motion-tolerant, it would also feature low visibility and generally minimal interference with daily-life activities. In order to achieve these long-term goals, we use a smartphone for EEG acquisition, stimulus presentation and online signal processing. In addition, we develop ear-EEG technology to capture meaningful brain activity unobtrusively. I will summarize our recent work showing that smartphones can handle EEG acquisition and experimental control reasonably well, and that they facilitate the combined recording of different signal streams, such as EEG and motion sensor signals. I will also report on the cEEGrids, flex-printed electrodes placed around the ear. Several validation studies, among which some compared cEEGrids with concurrently recorded high-density EEG signals, allow us to quantify the loss of information that is caused by limited spatial sampling from around the ear. While challenges remain to be tackled, our results document a proof of concept readiness level for both, smartphone EEG and ear-EEG. We conclude that both concepts will be indispensable in order to monitor brain states unobtrusively in daily-life situations.