Thursday, September 22nd
Pain-cognition Interactions in Healthy Individuals: Evidence for a Rewards-based Resource Competition
Pain can interfere with cognitive processes, resulting in forgetfulness, inability to focus, and difficulties in abstract thinking, problem solving and decision-making. A fundamental gap in our understanding is the mechanism of this interference, which would serve as a therapeutic target for pain. Prevailing models of this interference rely on distraction or salience competition, but these do not adequately fit behavioural data. Our imaging studies reveal a potentially different mechanism for this interaction. Specifically, the frontal polar cortex has abnormal structure and function in chronic pain. The frontal pole is implicated in cognitive branching –the ability to select a task based on its perceived value while tracking the perceived value of a competing task. Based on these findings, we propose that pain competition is not distraction or salience based, but is value-based. We performed an experiment that controls for salience, while testing the value-based framework. We show novel data supporting this concept: painful stimuli, but not salience-matched somatosensory stimuli, adversely affect task performance on a low-value, but not a high-value task. This indicates that value, and not salience, drive priority of task versus pain selection. In sum, we provide evidence for a value-based model of pain-cognition interactions in the human brain.