The scientists induced pain in 12 subjects by using a filament to touch their upper lips. Then they detected the associated increases in brain activity with a magnetic resonance imaging device. As the subject's pain was relieved with acupuncture needles placed between thumb and forefinger, scans showed activity diminished in up to 70% of the brain. Images taken of their brains showed the activity diminishing in up to 70%.

Study co-author Huey-Jen Lee said, "So many people with pain, whether from cancer, headache, or a chronic, unexplained condition, rely on medications, such as morphine, which can become addicting. Acupuncture has no side effects, and other studies have shown the pain relief it provides can last for months or permanently."