Electroencephalogram-based Brain–Computer Interface: An Introduction - Guide to Brain-Computer Music Interfacing - page 37

Fig. 2.7 Pass-colour biometric based on P300 VEP BCI a raw EEG b filtered EEG

alphanumeric characters will pop on the screen and when the character in the
password appears on screen, this evokes the P300 potential which is not evoked
when non-password characters appear. Similarly, colours can be used instead of
alphanumeric characters (having the advantage of being language independent) to
code a password (Gupta and Palaniappan 2013 ). For example, red-green-blue-red-
yellow could be the for someone.

Figure 2.7 a shows raw EEG signal, and Fig. 2.7 b shows the

' pass-colour '

filtered P300 signal
from channel Cz where the bolder line shows the focused or target colour and the
higher amplitude can be seen for the focused colour compared to the non-focused