Integrity of arousal-regulating brain circuitry predicts human cognitive abilities
Arousal state is regulated by the brainstem nucleus locus coeruleus, which sends wide-reaching projections to cortex. How this powerful neuromodulatory system is recruited to aid cognition is largely underexplored. Here, we hypothesized that select cortical regions may activate the arousal system, which in turn modulates large-scale brain activity, creating a circuit whose integrity predicts cognitive ability. We utilized the Human Connectome Project 7T functional magnetic resonance imaging dataset (N=149), acquired at rest with simultaneous eye tracking, along with extensive cognitive assessment for each subject. First, we discovered select frontoparietal cortical regions that likely drive large-scale spontaneous brain activity specifically via engaging the arousal system. Second, we show that the integrity of the arousal circuit driven by bilateral posterior cingulate cortex (associated with the default mode network) predicts subjects' cognitive abilities. This suggests that a cortical region that is typically associated with self-referential processing supports cognition by regulating the arousal system.