P300 speller BCI with a mobile EEG system: comparison to a traditional amplifier.
OBJECTIVE
In a previous study, we presented a low-cost, small and wireless EEG system enabling the recording of single-trial P300 amplitudes in a truly mobile, outdoor walking condition (Debener et al (2012 Psychophysiology 49 1449-53)). Small and wireless mobile EEG systems have substantial practical advantages as they allow for brain activity recordings in natural environments, but these systems may compromise the EEG signal quality. In this study, we aim to evaluate the EEG signal quality that can be obtained with the mobile system.


METHODS
We compared our mobile 14-channel EEG system with a state-of-the-art wired laboratory EEG system in a popular brain-computer interface (BCI) application. N = 13 individuals repeatedly performed a 6 × 6 matrix P300 spelling task. Between conditions, only the amplifier was changed, while electrode placement and electrode preparation, recording conditions, experimental stimulation and signal processing were identical.


RESULTS
Analysis of training and testing accuracies and information transfer rate (ITR) revealed that the wireless mobile EEG amplifier performed as good as the wired laboratory EEG system. A very high correlation for testing ITR between both amplifiers was evident (r = 0.92). Moreover the P300 topographies and amplitudes were very similar for both devices, as reflected by high degrees of association (r > = 0.77).


CONCLUSIONS
We conclude that efficient P300 spelling with a small, lightweight and quick to set up mobile EEG amplifier is possible. This technology facilitates the transfer of BCI applications from the laboratory to natural daily life environments, one of the key challenges in current BCI research.
Methods in Neurocognitive Psychology, Department of Psychology, University of Oldenburg, Oldenburg, Germany. Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany. Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany.
Maarten
M
De Vos
Markus
M
Kroesen
Reiner
R
Emkes
Stefan
S
Debener
D000328:Adult; D000669:Amplifiers, Electronic; D062207:Brain-Computer Interfaces; D003143:Communication Devices for People with Disabilities; D004569:Electroencephalography / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006260:Head Protective Devices; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007802:Language; D008297:Male; D008875:Middle Aged; D008904:Miniaturization; D018670:Monitoring, Ambulatory / Q000295:instrumentation; D011597:Psychomotor Performance / Q000502:physiology; D013686:Telemetry / Q000295:instrumentation*; D015443:Word Processing / Q000295:instrumentation; D055815:Young Adult