Strategic stabilization of arousal boosts sustained attention

Changes in autonomic arousal, such as mounting sleep pressure, and changes in motivation, such as fluctuating environmental reward statistics, both profoundly influence behavior. Our experience tells us that we have some capacity to control our arousal when doing so is important, such as staying awake while driving a motor vehicle. However, little is known about how decision computations are jointly influenced by arousal and motivation, including whether animals, such as rodents, can adapt their arousal state to their needs. Here, we developed and show results from an auditory feature-based sustained-attention task with intermittently shifting task utility. We use pupil size to estimate arousal across a wide range of states and apply novel signal detection theoretic and accumulation-to-bound modeling approaches in a large behavioral cohort. We find that both pupil-linked arousal and task utility have major impacts on multiple aspects of performance. Although substantial arousal fluctuations persist across utility conditions, mice partially stabilize their arousal near an intermediate, and optimal, level when task utility is high. Behavioral analyses show that multiple elements of behavior improve during high task utility and that arousal influences some, but not all, of them. Specifically, arousal influences the likelihood and timescale of sensory evidence accumulation, but not the quantity of evidence accumulated per time step while attending. In sum, the results establish specific decision-computational signatures of arousal, motivation, and their interaction, in attention. So doing, we provide an experimental and analysis framework for studying arousal self-regulation in neurotypical brains and diseases such as attention-deficit/hyperactivity disorder.