The beneficial effects of meditation have long been familiar to the general public; meditation has been known to increase pain tolerance, activity levels, and self-esteem, while decreasing anxiety, stress, depression, and the use of pain medications [1, 2].
There has been speculation with respect to the scientific basis of meditation’s positive effects . However, there are many recent studies that have scientifically proven the positive effects of meditation, specifically pain relief.
One such study is discussed in the research report Brain Mechanisms Supporting the Modulation of Pain by Mindfulness Meditation, where researchers at Wake Forest University explore the question of how meditation can elicit a form of pain relief by influencing the way pain is modulated and constructed by the brain . The researchers studied the effects of Shamatha of “focused attention” in particular, which involves learning how to observe what is happening in the mind without judging it, while simultaneously maintaining a deep focus on one’s breathing. The researchers used two independent variables: they altered the stimulus that the subjects received (using neutral or heat stimulation), as well as what activity the subjects performed before they experienced the stimulus (attention to breath (ATB) as a control, or the mindfulness meditation). The dependent variables that were measured in this experiment were pain intensity ratings and pain unpleasantness ratings, which were reported by the subjects, as well as deduced from brain images of the subjects produced by arterial spin labeling fMRIs.
The researchers conducted this experiment in four stages: psychophysical training, where the subjects were familiarized with a heat stimulus and with how to rate their pain intensity and unpleasantness; MRI Session I, where the subjects underwent the MRI scans after being in a resting condition as well as after attention to breath (ATB); meditation training, during which the subjects learned mindfulness meditation over a time span of 20 minutes every day for four days; and MRI session II, where the subjects were asked to meditate in the presence of heat and neutral stimuli and were subsequently monitored using the fMRI .
The results of this experiment indicate that meditation reduced the subjects’ pain unpleasantness ratings by 57% and their pain intensity ratings by 40%, showing that the pain experienced by all of the subjects was subdued by mindfulness meditation. In addition, by observing how various regions of the brain responded to meditation, the researchers found that meditation activated several areas of the brain that contribute to the cognitive modulation of pain , shedding light on the mechanisms by which meditation can change the way one experiences pain.
For example, one area that was studied in this experiment was the primary somatosensory cortex (SI), which is associated with the processing and discrimination of nociceptive information. In this experiment, meditation was found to significantly reduce pain-related processing in the SI. In addition, the anterior cingulate cortex (ACC) and the anterior insula (AI), known for their roles in controlling attention and in the cognitive regulation of pain processing, were activated. In examining the relationship between their two types of data (both the self-reported and those obtained through the MRIs), the experiment found that individuals who reported the greatest decreases in pain intensity ratings after meditation displayed the largest meditation-induced activation of the right AI and bilateral ACC. In addition, the researchers found that the activation of the mid-cingulate and AI overlapped between meditation and pain, indicating a likely area where meditation could specifically participate in pain modulation .
Other key areas that were observed during this experiment were the orbitofrontal cortex (OFC) and the thalamus. The researchers found that the individuals who reported the greatest decreases in pain unpleasantness ratings displayed the greatest activation of the OFC as well as the greatest deactivation of the thalamus . The OFC is an area of the brain that reframes the contextual evaluation of sensory events, and contributes to affective and emotional regulation processes. This region also participates in processing reward in the cognitive modulation of pain, allowing for immediate pain relief and a more positive mood. Thus, the activation of the OFC in subjects who reported decreased pain unpleasantness ratings shows that meditation influenced how these subjects evaluated their pain and their emotional response to the heat stimulation.
The thalamus was also deactivated in the subjects who experienced the greatest reduction in pain unpleasantness. The thalamic reticular nucleus (TRN) is a GABAergic structure that acts as a filter between the thalamus and frontal cortices. Through the MRIs, the researchers in this experiment concluded that meditation induced the activation of this limbic-thalamic gating mechanism, enabling the brain to control ascending noxious information before cortical regions that allow the pain to be consciously perceived by the subject received it . In this way, meditation could influence executive-order processes to alter how nociceptive information is translated into the subjective pain experience.
Thus, meditation was found to activate brain regions involved in the self-regulation of pain to a greater extent than attention to breath (ATB) achieved: it activated the areas involved in cognitive control (mid-ACC), emotional regulation (bilateral OFC), and interoceptive awareness (right AI), while deactivating regions that allow for a conscious perception of the pain (SI and thalamus).
The research demonstrates that even learning and practicing meditation for a short period of time can reduce a person’s sensitivity for pain. In fact, by comparing their results to those of similar studies, the researchers also found that the degree of pain reduction that was induced by meditation was greater than that by placebo pills, hypnosis, and even morphine and other painkilling drugs . This research has clinical implications; one follow-up study that could be performed would be to test the effects of meditation on individuals who experience long-term pain as a result of chronic illness. This could be applied in a clinical setting, where several subjects who experience a similar illness and undergo similar types of pain would be tested to see if meditation has an effect on alleviating their pain. Such a study could also use randomization of the treatment to provide some individuals with meditation training, others with prescribed pain medication proven to alleviate the pain, and again others with a placebo. This could answer the question of how meditation can influence long-term pain and how its effects compare to the effects of current medications used to treat pain. Such research would also expand upon the results of the experiment discussed above to include pain that is constantly occurring in the body. Lastly, it could have clinical implications and may provide information as to whether meditation can serve as a viable alternative to current medical pain alleviation treatment.
References Harding, Anne. “In pain? Try meditation.” http://www.cnn.com/2011/HEALTH/04/05/meditation.reduce.pain/  WebMD. “Hypnosis, Meditation, and Relaxation for Pain Treatment.” http://www.webmd.com/pain-management/hypnosis-meditation-and-relaxation-for-pain-treatment  Zeidan, F., Martucci, K. T., Kraft, R.A., Gordon, N.S., McHaffie, J.G., Coghill, R.C. (2011). Brain Mechanisms supporting the modulation of pain by mindfulness meditation. Journal of Neuroscience,31(14), 5540-8.  Gillis, Trent. “A Little Bit of Mindfulness Meditation Can Reduce a Lot of Pain” http://www.onbeing.org/blog/little-bit-mindfulness-meditation-can-reduce-lot-pain/2625.
Image Credit: Retrieved August 22, 2014 from: http://www.onbeing.org/blog/little-bit-mindfulness-meditation-can-reduce-lot-pain/2625