A POMDP Approach to Optimizing P300 Speller BCI Paradigm

• Published in: IEEE transactions on neural systems and rehabilitation engineering Vol. 20; no. 4; pp. 584 - 594
• Main Authors: Park, Jaeyoung, Kim, Kee-Eung
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.07.2012; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Ash; Bit rate; Brain - physiology; Brain-computer interface (BCI); Communication Aids for Disabled; Computational modeling; Electroencephalography; electroencephalography (EEG); Event-Related Potentials, P300 - physiology; Evoked Potentials - physiology; Female; Humans; Imagination - physiology; Language; Male; Markov Chains; P300; P300 speller; partially observable Markov decision process (POMDP); Pattern Recognition, Automated - methods; Schedules; Task Performance and Analysis; Training data; User-Computer Interface; Young Adult
• ISSN: 1534-4320; 1558-0210; 1558-0210
• DOI: 10.1109/TNSRE.2012.2191979

To achieve high performance in brain-computer interfaces (BCIs) using P300, most of the work has been focused on feature extraction and classification algorithms. Although significant progress has been made in such signal processing methods in the lower layer, the issues in the higher layer, specifically determining the stimulus schedule in order to identify the target reliably and efficiently, remain relatively unexplored. In this paper, we propose a systematic approach to compute an optimal stimulus schedule in P300 BCIs. Our approach adopts the partially observable Markov decision process, which is a model for planning in partially observable stochastic environments. We show that the thus obtained stimulus schedule achieves a significant performance improvement in terms of the success rate, bit rate, and practical bit rate through human subject experiments.