MRI scans will be acquired on a 3T scanner in NCKU. The special technician will help us and the patient for MRI scan and the setting of all MRI parameter. Dr. Sun and a qualified radiologist will help for data analysis after MRI performance. The investigators will also follow the method that described before[19]: An anatomical scan will be acquired at the beginning of the session and lasted 5 min. The following parameters will be used: echo time (TE) 3 ms, repetition time (TR) 2.3 s, flip angle 9。, resolution 1*1*1 mm. During a functional scan of ~5 min, subjects will perform the Multi-Source Interference Task as previous reported[22, 23]. The task stimuli will be presented on a screen in the subjects' view while lying in the MRI scanner, and subjects will respond on a three-button response box. The task has three levels of difficulty, a motor control task, and easy level and a difficult level. The task will enhance the brain network if pain persistent[23]. The parameters for functional scan were as follow: echo-planar imaging, TE 3 ms, TR 2.26s, flip angle 90。, 128 frames, 64*64 matrix, 38 slices for whole-brain coverage, resolution 4*4*4 mm. Images were acquired in the axial plane, plus 30。 from the anterior commissure-posterior commissure line to avoid the eyes. The fMRI data analysis will be help under our university team.