Observing the steady-state visual evoked potentials with a compact quad-channel spin exchange relaxation-free magnetometer

Du Peng-Cheng^{1, 3}, Li Jian-Jun^{1, 3}, Yang Si-Jia^{2, 4, 6}, Wang Xu-Tong¹, Zhuo Yan^{2, 4, 6}, Wang Fan^{2, 4, 5, 6, ‡}, Wang Ru-Quan^{1, 3, §}

Colored lines represent the values for the four sensor channels and EEG: CH-A (square), CH-B (circle), CH-C (up triangle), CH-D (down triangle) of the OPM sensor, and EEG (purple line). (a) Magnetic field strength of the SSVEP responses for different stimulation frequencies (10 Hz, 12.5 Hz, and 15 Hz). (b) The SNR for different stimulation frequencies (10 Hz, 12.5 Hz, and 15 Hz).