Abstract
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 ensuing behaviors and to help optimize task performance (exploitation). When utility in the task wanes, LC neurons exhibit a tonic activity mode, associated with disengagement from the current task and a search for alternative behaviors (exploration). Monkey LC receives prominent, direct inputs from the anterior cingulate (ACC) and orbitofrontal cortices (OFC), both of which are thought to monitor task-related utility. We propose that these frontal areas produce the above patterns of LC activity to optimize utility on both short and long timescales.
Original language | English (US) |
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Pages (from-to) | 403-450 |
Number of pages | 48 |
Journal | Annual Review of Neuroscience |
Volume | 28 |
DOIs | |
State | Published - 2005 |
All Science Journal Classification (ASJC) codes
- Neuroscience(all)
Keywords
- Anterior cingulate cortex
- Decision making
- Neuromodulation
- Optimization
- Orbitofrontal cortex
- Utility