Operation of a P300-based brain–computer interface by individuals with cervical spinal cord injury

Abstract

Objective This study evaluates the efficacy of a P300-based brain–computer interface (BCI) with green/blue flicker matrices for individuals with cervical spinal cord injury (SCI). Methods Ten individuals with cervical SCI (age 26–53, all male) and 10 age- and sex-matched able-bodied controls (age 27–52, all male) with no prior BCI experience were asked to input hiragana (Japanese alphabet) characters using the P300 BCI with two distinct types of visual stimuli, white/gray and green/blue, in an 8×10 flicker matrix. Both online and offline performance were evaluated. Results The mean online accuracy of the SCI subjects was 88.0% for the white/gray and 90.7% for the green/blue flicker matrices. The accuracy of the control subjects was 77.3% and 86.0% for the white/gray and green/blue, respectively. There was a significant difference in online accuracy between the two types of flicker matrix. SCI subjects performed with greater accuracy than controls, but the main effect was not significant. Conclusions Individuals with cervical SCI successfully controlled the P300 BCI, and the green/blue flicker matrices were associated with significantly higher accuracy than the white/gray matrices. Significance The P300 BCI with the green/blue flicker matrices is effective for use not only in able-bodied subjects, but also in individuals with cervical SCI.