AsianScientist (Nov. 12, 2015) – A brain-computer interface (BCI) technology capable of high speed spelling mediated by brain waves has been reported by a group of Chinese scientists. They published their findings in the journal Proceedings of the National Academy of Sciences.
The BCI technology provides a new communication channel. Although the field has made unprecedented progress in the past 20 years, its low communication rates remain a key obstacle to BCI-based communication.
In the present study, a team led by Dr. Wang Yijun from the State Key Laboratory Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, developed an electroencephalogram (EEG)-based brain speller. It achieved information transfer rates of up to 5.32 bits per second, a new world record for brain spellers using either non-invasive or invasive methods.
Based on the extremely high consistency of frequency and phase observed between the visual flickering signals and the elicited single-trial steady-state visual evoked potentials, Wang and his collaborators from Tsinghua University and University of California San Diego, developed a synchronous modulation and demodulation paradigm to implement the BCI speller.
Specifically, they propose a new joint frequency-phase modulation (JFPM) method to tag 40 characters with 0.5-seconds-long flickering signals, and develop a user-specific target identification algorithm using the individual calibration data.
The resulting speller obtains high spelling rates up to 60 characters (∼12 words) per minute. For the first time, this work demonstrates that BCIs can provide a truly naturalistic high-speed communication channel using non-invasively recorded brain activities.
The article can be found at: Chen et al. (2015) High-Speed Spelling With a Non-Invasive Brain–Computer Interface.
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Source: Chinese Academy of Sciences.
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