Fig. 6.

Information transfer rates of current BCI spellers. The data points indicate BCI studies characterized by “online” and “speller” from Thomson Reuters Web of Science and the present study. To emphasize practicality, the studies without online spelling tasks were not included. The line shows a linear fit for all data points, indicating a significant increase of ITR during the past decade (P < 0.01, r = 0.53). ”mVEP” indicates motion VEP and ”hybrid” indicates systems using multiple EEG signals (e.g., SSVEP and P300).