According to this theory, pain signals must pass through a number of high-traffic “gates” as they move from the area of injury upward through the spinal cord into the brain. Like a road or highway, these nerves can handle only a limited number of nerve signals at one time. The pain signal travels very slowly. We can generate other signals which move faster. The faster signals crowd out the slower ones because of the limited capacity of the nerves. Remember the time sitting in traffic near a construction zone, where the two lanes merge into one. The fast cars on the merging lanes go further and merge ahead of the slower ones, making it nearly impossible for the slow traffic on the lane to move forward. Now think about the pain signals are the slow ones sitting there waiting for an opening to move through. If one can produce enough fast signals, it can effectively crowd out the pain signals. Acupuncture generates competing stimulus and effectively blocks the slow pain signals from reaching the brain. The result: we never “experience the pain”.