Strategy-dependent dissociation of the neural correlates involved in pain modulation
Background: Cognitive strategies are a set of psychologic behaviors used to modulate one's perception or interpretation of a sensation or situation. Although the effectiveness of each cognitive strategy seems to differ between individuals, they are commonly used clinically to help patients with chronic pain cope with their condition. The neural basis of commonly used cognitive strategies is not well understood. Understanding the neural correlates that underlie these strategies will enhance understanding of the analgesic network of the brain and the cognitive modulation of pain. Methods: The current study examines patterns of brain activation during two common cognitive strategies, external focus of attention and reappraisal, in patients with chronic pain using functional magnetic resonance imaging. Results: Behavioral results revealed interindividual variability in the effectiveness of one strategy versus another in the patients. Functional magnetic resonance imaging revealed distinct patterns of activity when the two strategies were used. During external focus of attention, activity was observed mainly in cortical areas including the postcentral gyrus, inferior parietal lobule, middle occipital gyrus, and precentral gyrus. The use of reappraisal evoked activity in the thalamus and amygdala in addition to cortical regions. Only one area, the postcentral gyrus, was observed to be active during both strategies. Conclusions: The results of this study suggest that different cognitive behavioral strategies recruit different brain regions to perform the same task: pain modulation. © 2011, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins. Anesthesiology.