Fig. 8

Perfusion index image of cerebral blood flow in a healthy volunteer. a Pre-stimulation; b post-stimulation. Grey oval shows the used ROI. Volunteer #10, stimulation power = 90%
Perfusion index image of cerebral blood flow in a healthy volunteer. a Pre-stimulation; b post-stimulation. Grey oval shows the used ROI. Volunteer #10, stimulation power = 90%