Historically, the locus coeruleus-norepinephrine (LC-NE) system has been implicated in
arousal, but recent findings suggest that this system plays a more complex and specific role
in the control of behavior than investigators previously thought. We review
neurophysiological and modeling studies in monkey that support a new theory of LC-NE
function. LC neurons exhibit two modes of activity, phasic and tonic. Phasic LC activation is
driven by the outcome of task-related decision processes and is proposed to facilitate …