The ascending arousal system promotes optimal performance through meso-scale network integration in a visuospatial attentional task

There is evidence that the autonomic nervous system provides important constraints over ongoing cognitive function, however there is currently a lack of direct empirical evidence for how this interaction manifests in the brain. Here, we examine the role of ascending arousal and attentional load on large-scale network dynamics by combining pupillometry, functional MRI, and graph theoretical analysis to analyze data from a visual motion-tracking task with a parametric load manipulation. We found that attentional load effects were observable in measures of pupil diameter and in a set of brain regions that parametrically modulated their BOLD activity and meso-scale network-level integration. In addition, the regional patterns of network configuration were predicted by the distribution of the adrenergic receptor density. Our results provide confirmatory evidence for adaptive gain theory and strengthen the relationship between ascending noradrenergic tone, large-scale network integration, and cognitive task performance.