Fig. 5From: 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 general frequency-domain resting-state (left) or task-elicited (right) fNIRS data without periodic FE stimuli with SSVEP. The unit of the x-axis is seconds while the y-axis has no unitsBack to article page