In an article that will be in the journal Pain, the main author from Wake Forest Baptist Medical Center reports that an individual’s sensitivity to pain appears to be related to some degree to the amount of grey matter in certain areas of the brain.
The researchers came to this conclusion after they analyzed data from ten previous studies, involving 116 subjects who underwent the same sensory tests: Subjects rated the intensity of pain when a small spot of skin on the arm or leg was heated to 120 degrees Fahrenheit; magnetic resonance imaging (MRI) of the brain was performed on these subjects two days later. The investigators were not searching for acute changes in brain activity in response to painful stimuli; rather, they were trying to observe evidence of structural variations that would have been present over time — with the ultimate goal of correlating pain sensitivity with brain structure.
In other words, is there a certain appearance to the brain anatomy, when the brain is NOT experiencing pain, that will allow us to predict how sensitive whoever owns that brain is to a painful stimulus?
Indeed, the subject who had the higher pain intensity ratings had less grey matter in the following areas of the brain: the cingulated cortex, the precuneus, and certain sections of the posterior parietal cortex. Of note, these are areas of the brain that contribute to one’s internal thoughts and control of attention: Working together, these brain regions are associated with free-flowing thoughts that the daydreamers of the world experience.
So, daydreams appear to compete with the brain activity that generates what we humans experience as pain. Individuals who daydream more would have less sensitivity to pain. Pain must compete with daydreams.
But be careful what you wish for: In the case of acute pain, it is nice to be acutely aware of it, so you don’t waste any time in pulling away from that cactus you just fell into while hiking. In contrast, someone with chronic pain would likely prefer not to dwell on its existence. It is all about preoccupation, the brain overruling one thing to focus on another.
Yes, pain will always be good at getting our attention, but we may be able to modulate this sensitivity to pain by using our brains to take our thoughts to a less painful place. Once again, the power of meditation and mindfulness is called upon. More than just an aside, it should be noted that individuals who do meditate long-term have been shown to have more grey matter in those areas of the brain associated with sensitivity to pain.
Health care professionals need to consider these correlates between anatomy and cognition, as it could be the case that some patients who are at baseline less sensitive to pain may be overmedicated, and thus at risk for all the associated problems — including addiction and potentially life-threatening side effects. The identification of such patients could allow for a minimization of medication doses. Meantime, more medications could be administered to those individuals who do have the greater inherent pain sensitivity.
At the present time, patients are often given medications based on their body weight. Someday, medications might be dosed based on amount of grey matter.
Pleasant daydreams. Who says size doesn’t matter?