Published December 13, 2010
Meditation is a known painkiller, easing people's pain perception even after brief sessions. Now a study reveals why: Meditation changes the way the brain processes pain signals.
In a study presented Nov. 16 in San Diego at the annual meeting of the Society for Neuroscience, researchers reported that practicing a mindful awareness of the body and consciousness for just four days affects pain responses in the brain.
Brain activity decreases in areas devoted to the painful body part and in areas responsible for relaying sensory information. Meanwhile, regions that modulate pain get busy, and volunteers report that pain is less intense and less unpleasant.
Earlier studies suggested meditation reduces anxiety, promotes relaxation and helps people regulate their emotions, said study author Fadel Zeidan, a post-doctoral researcher at the Wake Forest University School of Medicine. Also, meditation may reduce pain by essentially making the physical sensations less distressing. "It's really all about the context of the situation, of the environment," Zeidan told LiveScience. "Meditation seems to have an overarching sense of attenuating that type of response."
The practice known as mindfulness meditation involves sitting quietly and comfortably while breathing evenly. The idea is to clear the mind and focus the attention on the present.
Many studies have found that practicing meditation can reduce pain. Zeidan's work suggests you don't have to spend much time meditating to get the benefit: In a study published in March in the Journal of Pain, Zeidan and his colleagues reported that a half-hour of training per day for three days can significantly soothe pain, even when research participants aren't meditating.
In the new study, Zeidan wanted to find out what meditation does to change the brain's pain response. So he and his colleagues asked 15 volunteers to spend 30 minutes each day for four days learning to meditate. Before and after the training, the researchers scanned the volunteers' brains using magnetic resonance imaging.
During both before and after scans, each volunteer experienced alternative sensations of heat (120 degrees Fahrenheit, or 49 degrees Celsius) and neutral temperature (95 degrees F, or 35 degrees C) on his or her calf. After each 12-second temperature application, the volunteers ranked their pain by pushing a lever to the right for more pain and to the left for less. The lever position corresponded to a scale of 1 to 10, with 10 representing the greatest pain.
All in your head
The results are not yet published, but according to the Society for Neuroscience research abstract, meditation reduced people's perceptions of pain's unpleasantness by 57 percent. Volunteers also reported that pain was 40 percent less intense. [5 Painful Facts You Need to Know]
The volunteers' brains mirrored their altered perceptions, according to the abstract. Activity dropped in the thalamus, a deep brain area that relays sensory information from the body to the somatosensory cortex. The somatosensory cortex, located along the side of the brain above the ear, has specialized areas devoted to processing signals from specific body parts. In the meditation-practicing volunteers, the area of the somatosensory cortex linked to the calf was quieted.
Meanwhile, areas associated with pain modulation became more active. Those areas included the orbitofrontal cortex directly behind the eyes and the anterior cingulated cortex deep in the frontal region of the brain. The putamen, a structure buried in the center of the brain, and the nearby insula also showed more activity. Both structures have many functions, including control of movement, self-awareness and perception.
"The preliminary results are very interesting and promising," Zeidan said. The good news, he said, is that studies have shown that meditation's benefits occur rapidly, making it a realistic pain-relief option for people facing surgery or enduring injury.
"You don't necessarily need to be a monk to experience some of the benefits related to meditation," he said.