Enhancing Acupuncture Treatment Effect Through Non-invasive Neuromodulation

Inclusion Criteria: * volunteers 18-60 years of age * meet the classification criteria of chronic low back pain (having low back pain for more than 6 months), as determined by the referring physician * at least 4/10 clinical pain on the 11-point Low Back Pain Numeric Rating Scale (LBP NRS) * at least a 10th grade English-reading level; English can be a second language provided that the patients understand all questions used in the assessment measures Exclusion Criteria: * history of epilepsy or loss consciousness (LOC) * specific causes of back pain (e.g. cancer, fractures, spinal stenosis, infections) * complicated back problems (e.g. prior back surgery, medicolegal issues) * the intent to undergo surgery during the time of involvement in the study * history of cardiac, respiratory, or nervous system disease that, in the investigator's judgment, precludes participation in the study because of a heightened potential for adverse outcomes. For example: asthma or claustrophobia * presence of any contraindications to magnetic resonance imaging (MRI) scanning. For example: cardiac pacemaker, metal implants, claustrophobia, pregnancy, inability to remain still in MRI scanner * history of medical or psychiatric illness as determined by the investigator * history of substance abuse or dependence