To assess how acupuncture pain relief develops over a 17-session, twice weekly acupuncture course. We will assess acupuncture's effect on pain perception by repeated assessments of the following: 1) Measuring responses to low level brief electric zaps delivered to the hand (pain rating no more than 4/10 on a 1-10 scale), using 2 scalp electrodes for brain wave recordings. 2) Measuring heat pain detection using a mildly painful heat probe, touching the hand (pain rating no more than 5/10 on a 1-10 scale, lasting seconds). 3) Asking participants to fill out a brief low back pain questionnaire.