I have a good friend, Dennis, who related an interesting experience he had regarding Sensitization to Pain.
It occurred when he was working as a hod carrier in his early twenties. A hod carrier is a person who sets up the work area for brick masons. Essentially, the hod carrier enables the brick masons to lay blocks or bricks as efficiently as possible. The work involves mixing cement and carrying it along with the building materials to the next section of wall. This has to be done fast enough to stay ahead of the masons. The materials also often have to be hauled up scaffolding. The masons are not usually very happy if the hod carrier falls behind. It is an extraordinarily intense, physical job.
On one particular job, Denis’s duties also included cutting blocks of basalt with a “wet” saw. This is a saw with an industrial diamond blade. To keep the blade from overheating, water from a small sump pump is continuously pumped over the blade. One day on the site, he felt a very mild tingling sensation as he placed his hand on the saw handle. As he cut blocks early in the morning, the sensation was not particularly uncomfortable. As the morning progressed, the sensation gradually became stronger. By early afternoon, the sensation was so strong that he could no longer comfortably touch the handle. He felt an actual shock. Even the anticipation of the sensation became a problem, and he would not touch the handle.
At First, Only Dennis Could Feel the Pain
There were three hod carriers on this crew. They watched him get more and more cautious and finally refuse to touch the handle. Yet when they touched the handle, they could barely feel anything. Needless to say, they gave him a hard time.
Then, They All Felt the Pain
The next day, they rotated and the second guy had the same experience. By mid-afternoon he would no longer touch the handle. The third guy now thought they were “toying” with him. Again, when he touched the handle, the sensation was almost imperceptible.
The third day was his turn, and by mid-afternoon he was a believer. The ultimate cause of this phenomenon, a frayed wire, was finally fixed on the fourth day.
Your Body Learns Pain Over Time
What is interesting to me about this story is the degree of difference in sensation over just six to seven hours of repeated exposure. If the initial impulse had been somewhat uncomfortable, the story would have seemed more plausible. However, the sensation went from barely perceptible to an electric shock. Dennis said that even the anticipation of touching the handle produced a physical sensation.
The Pain is Real; It’s in your Brain
It would be reasonable to assume that if a functional MRI was available to measure the hod carriers’ brain activity throughout the day, there would be an increased number of areas of the brain firing by the end of the day.
Your nervous system is incredibly adaptable. It does not take much repetition for your brain to figure out how to process a known, predictable impulse.