High-Rate Steady-State Visual Evoked
Potential-Based BCI
Cheng et al. [2] recently developed an online BCI that
detected and classified steady-state visual evoked potential
(SSVEP) measured with as few as 2 active electrodes.
Twelve buttons illuminated at different refresh rates were
displayed on a computer monitor. The buttons constituted
a virtual telephone keypad, representing the ten digits
0–9, BACKSPACE, and ENTER. Users could input phone
numbers by looking at these buttons. The induced frequency-
coded SSVEP was used to determine user button
selection. Eight of the 13 subjects succeeded in dialing the
desired number using brain activity. The average transfer
rate over all subjects was 27.15 bits/min – one of the fastest
communication rates described in the BCI literature.
The BCI system also employed a wireless transmitter to
allow users more freedom of movement.