Fig. 3From: Functional near-infrared spectroscopy can detect low-frequency hemodynamic oscillations in the prefrontal cortex during steady-state visual evoked potential-inducing periodic facial expression stimuli presentationThe time-domain of HbO signals during periodic SSVEP-inducing FE stimuli presentation. The time course of fNIRS data is grand-averaged across all conditions and participants. The unit of the x-axis is seconds while the unit of the y-axis is micromolesBack to article page