Task-Relevant Stimulus Design Improves P300-Based Brain-Computer Interfaces

Kim, J.; Kim, S.-P.; Cho, Y. S.

doi:10.1101/2024.05.01.592004

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bioRxiv · 10.1101/2024.05.01.592004

Task-Relevant Stimulus Design Improves P300-Based Brain-Computer Interfaces

Kim, J.·Kim, S.-P.·Cho, Y. S.

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Abstract

ObjectiveIn the pursuit of refining P300-based brain-computer interfaces (BCIs), our research aims to propose a novel stimulus design focused on selective attention and task relevance to address the challenges of P300-based BCIs, including the necessity of repetitive stimulus presentations, accuracy improvement, user variability, and calibration demands. ApproachIn the oddball task for P300-based BCIs, we develop a stimulus design involving task-relevant dynamic stimuli implemented as finger-tapping to enhance the elicitation and consistency of event-related potentials (ERPs). We further improve the performance of P300-based BCIs by optimizing ERP feature extraction and classification in offline analyses. Main ResultsWith the proposed stimulus design, online P300-based BCIs in 37 healthy participants achieves the accuracy of 91.2% and the information transfer rate (ITR) of 28.37 bits/min with two stimulus repetitions. With optimized computational modeling in BCIs, our offline analyses reveal the possibility of single-trial execution, showcasing the accuracy of 91.7% and the ITR of 59.92 bits/min. Furthermore, our exploration into the feasibility of across-subject zero-calibration BCIs through offline analyses, where a BCI built on a dataset of 36 participants is directly applied to a left-out participant with no calibration, yields the accuracy of 94.23% and the ITR of 31.56 bits/min with two stimulus repetitions and the accuracy of 87.75% and the ITR of 52.61 bits/min with single-trial execution. When using the finger-tapping stimulus, the variability in performance among participants is the lowest, and a greater increase in performance is observed especially for those showing lower performance using the conventional color-changing stimulus. SignficanceUsing a novel task-relevant dynamic stimulus design, this study achieves one of the highest levels of P300-based BCI performance to date. This underscores the importance of coupling stimulus paradigms with computational methods for improving P300-based BCIs.

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Kim, J., Kim, S.-P., Cho, Y. S.. 2024-05-04. Task-Relevant Stimulus Design Improves P300-Based Brain-Computer Interfaces. https://doi.org/10.1101/2024.05.01.592004

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