Brain-Computer Interface Research at the University of South Florida Cognitive Psychophysiology Laboratory: The P300 Speller

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Psychology, Laboratories, Biomedical imaging, Enterprise resource planning, Displays, Keyboards, Pediatrics, Humans, Biomedical engineering, Systems engineering and theory

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We describe current efforts to implement and improve P300-BCI communication tools. The P300 Speller first described by Farwell and Donchin (in 1988) adapted the so-called oddball paradigm (OP) as the operating principle of the brain-computer interface (BCI) and was the first P300-BCI. The system operated by briefly intensifying each row and column of a matrix and the attended row and column elicited a P300 response. This paradigm has been the benchmark in P300-BCI systems, and in the past few years the P300 Speller paradigm has been solidified as a promising communication tool. While promising, we have found that some people who have amyotrophic lateral sclerosis (ALS) would be better suited with a system that has a limited number of choices, particularly if the 6/spl times/6 matrix is difficult to use. Therefore, we used the OP to implement a four-choice system using the commands: Yes, No, Pass, and End; we also used three presentation modes: auditory, visual, and auditory and visual. We summarize results from both paradigms and also discuss obstacles we have identified while working with the ALS population outside of the laboratory environment.

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IEEE Transactions on Neural Systems and Rehabilitation Engineering, v. 14, issue 2, p. 221-224