Abstract
Neuromodulators help balance the trade-off between flexibility and stability that is needed for adaptive cognition and behaviour. Among the neuromodulators, the noradrenergic system plays a key role in balancing this trade-off: it helps shape whether we pursue a given behaviour or task, versus shifting our behaviour to pursue an alternate strategy. Put differently, the noradrenergic system drives the balance between a stable versus flexible engagement with the world around us. How might this capacity relate to human thought? In this chapter, we review the functional and organisational principles of the locus coeruleus–noradrenergic system, and consider how it might modulate different aspects of human thought. Highlighting examples from attention, belief-updating, spontaneous thought and stress. Together, revealing how the locus coeruleus–noradrenergic system helps shape the balance of flexibility and stability in human thought.