Pain attenuation through mindfulness is associated with decreased cognitive control and increased sensory processing in the brain

Abstract

Pain can be modulated by several cognitive techniques, typically involving increased cognitive control and decreased sensory processing. Recently, it has been demonstrated that pain can also be attenuated by mindfulness. Here, we investigate the underlying brain mechanisms by which the state of mindfulness reduces pain. Mindfulness practitioners and controls received unpleasant electric stimuli in the functional magnetic resonance imaging scanner during a mindfulness and a control condition. Mindfulness practitioners, but not controls, were able to reduce pain unpleasantness by 22% and anticipatory anxiety by 29% during a mindful state. In the brain, this reduction was associated with decreased activation in the lateral prefrontal cortex and increased activation in the right posterior insula during stimulation and increased rostral anterior cingulate cortex activation during the anticipation of pain. These findings reveal a unique mechanism of pain modulation, comprising increased sensory processing and decreased cognitive control, and are in sharp contrast to established pain modulation mechanisms.

Figure 1.

Stimulation protocol. Mindfulness and baseline conditions consisted of an instruction phase, a stimulation phase with 3 random shocks, and a rating phase in which intensity, unpleasantness, and anticipatory anxiety were rated on a visual rating scale. Each condition was presented 6 times, and orders were permutated within and over subjects. Inst. = instruction, sec.=seconds.

Figure 2.

Pain (a) intensity, (b) unpleasantness, and (c) anticipatory anxiety ratings for mindfulness practitioners (pract.) and controls in the mindfulness and baseline condition. Error bars represent standard error of the mean.

Figure 3.

Activation in response to electric stimulation in (a) mindfulness practitioners and (b) controls during the baseline condition. Maps are the result of a whole-brain random effects analysis and are cluster level corrected for multiple comparisons at P < 0.05 (voxel threshold P < 0.001, extent 6 for a and 7 for b).

Figure 4.

Activation during the baseline (blue) and mindfulness (green) condition for mindfulness practitioners (MP) and controls (CT), (a) while anticipating electric shocks and (b) while receiving electric shocks. Maps are the result of a whole-brain random effects analysis, are cluster level corrected for multiple comparisons at P < 0.05 (voxel threshold P < 0.05, extent 41 for stimulation and 44 for anticipation contrasts), and represent the interaction between group (mindfulness practitioners vs. controls) and condition (mindfulness vs. baseline). Red: activation greater in mindfulness practitioners; blue: activation greater in controls. Bars represent parameter estimates, error bars are standard errors of the mean. STG = Superior temporal gyrus (BA22).

Figure 5.

Correlations between reduction in pain unpleasantness during mindfulness and increased brain activity during mindfulness in posterior Insula/S2, for controls (solid line) and mindfulness practitioners (dashed line) separately.