Neurophysiological studies are typically conducted in laboratories with limited ecological validity, scalability, and generalizability of findings. This is a significant challenge for the development of braincomputer interfaces (BCIs), which ultimately need to function in unsupervised settings on consumer-grade hardware. We introduce MYND: A framework that couples consumer-grade recording hardware with an easy-to-use application for the unsupervised evaluation of BCI control strategies. Subjects are guided through experiment selection, hardware fitting, recording, and data upload in order to selfadminister multi-day studies that include neurophysiological recordings and questionnaires. As a use case, we evaluate two BCI control strategies ("Positive memories" and "Music imagery") in a realistic scenario by combining MYND with a four-channel electroencephalogram (EEG). Thirty subjects recorded 70.4 hours of EEG data with the system at home. The median headset fitting time was 25.9 seconds, and a median signal quality of 90.2% was retained during recordings. Neural activity in both control strategies could be decoded with an average offline accuracy of 68.5% and 64.0% across all days. The repeated unsupervised execution of the same strategy affected performance, which could be tackled by implementing feedback to let subjects switch between strategies or devise new strategies with the platform.
Significance StatementUsing thoughts to interact with our environment could be the next frontier of medical and personal technology. The deployment of brain-computer interfaces (BCIs) on affordable hardware in daily life is the ultimate goal of this field, and both researchers and users need novel ways to evaluate conceptual systems under realistic conditions. We present a framework for the unsupervised evaluation of BCI control strategies on a consumer-grade electroencephalogram. We show that combining real-time guidance for hardware administration with a set of control strategies that induce broad spatial modulations in neural activity may be a viable basis for research on accessible BCI usage in daily life. M. R. H., M. G-W., and B. S. had the idea of building a platform for large-scale EEG recordings. M. R. H. designed and developed the platform, conducted experiments, analysed and interpreted the data, performed a literature review, and wrote the paper. M. H. and B. W. assisted with the design of the platform. L. K., M. L. and B. W. assisted with experiments. T. Z. and R. E. assisted with software development. M. G-W. and B. S. provided advice on the platform development and supervised the work.