Abstract
Social perception allows us to rapidly interpret others' emotions, intentions, and actions, yet the underlying neural mechanisms remain incompletely understood. Here, we propose a framework linking neuromodulatory function to large-scale networks involved in social perception. The framework centers on the locus coeruleus-norepinephrine (LC–NE) system as an orchestrator of cortical networks. We argue that social perception is optimized when moderate tonic LC activity is paired with strong phasic responses to social-emotional cues, enabling selective attention, flexible updating of expectations, and accurate interpretation of social information. By contrast, both reduced and excessive LC activity are predicted to impair social perception. LC hypoactivity limits engagement with socially relevant cues, whereas hyperactivity produces diffuse arousal, distractibility, and hypervigilance, reducing discrimination of relevant from irrelevant social signals. We further propose that social perception emerges through modulation of local cortical gain, large-scale brain networks, and perceptual evidence accumulation, providing a mechanistic bridge between cellular processes and social behavior. Finally, we outline testable predictions and consider how disrupted LC function may contribute to social cognitive deficits in aging, neurodegenerative diseases, and neuropsychiatric disorders. By placing the LC–NE system as orchestrator of adaptive social perception, this framework offers a unifying account of how neuromodulation shapes social behavior.