I. Introduction
ACUPUNCTURE is an ancient Chinese healing technique which has been used to treat various illnesses for thousands of years [1]. Although it has gained great popularity as an alternative and complementary therapeutic intervention in the Western medicine, the neural mechanism underlying acupuncture is still unknown. In the past decades, noninvasive functional Magnetic Resonance Imaging (fMRI) techniques have provided new insights into the anatomy and physiological function underlying acupuncture [2]–[11].