On brain-computer interface technology based on dual- layer SSVEP

The principle of brain-computer interface (BCI) based on SSVEP is studied. A new method of dual-layer SSVEP for BCI system is proposed, in which M×M objects can be controlled by M stimulation frequencies. The telephone keyboard BCI virtual platform based on dual-layer SSVEP is established. Design a visual stimulator with four light emitting diodes (LED) flickering rates (12, 15, 18, 20 Hz), which induces subjects´ dual-layer SSVEP to control the telephone keyboard with 12 numbers and 4 function keys. The results show that the proposed method produces more selections using less stimulation frequencies, which verifies the feasibility of the BCI technology based on dual-layer SSVEP.