Near-infrared spectroscopy (NIRS)-based eyes-closed brain-computer interface (BCI) using prefrontal cortex activation due to mental arithmetic.
We propose a near-infrared spectroscopy (NIRS)-based brain-computer interface (BCI) that can be operated in eyes-closed (EC) state. To evaluate the feasibility of NIRS-based EC BCIs, we compared the performance of an eye-open (EO) BCI paradigm and an EC BCI paradigm with respect to hemodynamic response and classification accuracy. To this end, subjects performed either mental arithmetic or imagined vocalization of the English alphabet as a baseline task with very low cognitive loading. The performances of two linear classifiers were compared; resulting in an advantage of shrinkage linear discriminant analysis (LDA). The classification accuracy of EC paradigm (75.6 ± 7.3%) was observed to be lower than that of EO paradigm (77.0 ± 9.2%), which was statistically insignificant (p = 0.5698). Subjects reported they felt it more comfortable (p = 0.057) and easier (p < 0.05) to perform the EC BCI tasks. The different task difficulty may become a cause of the slightly lower classification accuracy of EC data. From the analysis results, we could confirm the feasibility of NIRS-based EC BCIs, which can be a BCI option that may ultimately be of use for patients who cannot keep their eyes open consistently.
Machine Learning Group, Berlin Institute of Technology (TU Berlin), Marchstr. 23, 10587 Berlin, Germany.
Jaeyoung
J
Shin
Machine Learning Group, Berlin Institute of Technology (TU Berlin), Marchstr. 23, 10587 Berlin, Germany.|Department of Brain and Cognitive Engineering, Korea University, 136-713 Seoul, Korea.
Klaus-R
KR
Müller
Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, 730-701 Gumi, Korea.
Han-Jeong
HJ
Hwang
D000328:Adult; D062207:Brain-Computer Interfaces; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008606:Mental Processes / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation*; D055815:Young Adult