Abstract
The locus coeruleus (LC) in the pons is the major source of noradrenaline (NA) in the brain. Two modes of LC firing have been associated with distinct cognitive states: changes in tonic rates of firing are correlated with global levels of arousal and behavioural flexibility, whilst phasic LC responses are evoked by salient stimuli. Here, we unify these two modes of firing by modelling the response of the LC as a correlate of a prediction error when inferring states for action planning under Active Inference (AI).
We simulate a classic Go/No-go reward learning task and a three-arm foraging task and show that, if LC activity is considered to reflect the magnitude of high level 'state-action' prediction errors, then both tonic and phasic modes of firing are emergent features of belief updating. We also demonstrate that when contingencies change, AI agents can update their internal models more quickly by feeding back this state-action prediction error - reflected in LC firing and noradrenaline release - to optimise learning rate, enabling large adjustments over short timescales. We propose that such prediction errors are mediated by cortico-LC connections, whilst ascending input from LC to cortex modulates belief updating in anterior cingulate cortex (ACC).
In short, we characterise the LC/ NA system within a general theory of brain function. In doing so, we show that contrasting, behaviour-dependent firing patterns are an emergent property of the LC's crucial role in translating prediction errors into an optimal mediation between plasticity and stability.
We simulate a classic Go/No-go reward learning task and a three-arm foraging task and show that, if LC activity is considered to reflect the magnitude of high level 'state-action' prediction errors, then both tonic and phasic modes of firing are emergent features of belief updating. We also demonstrate that when contingencies change, AI agents can update their internal models more quickly by feeding back this state-action prediction error - reflected in LC firing and noradrenaline release - to optimise learning rate, enabling large adjustments over short timescales. We propose that such prediction errors are mediated by cortico-LC connections, whilst ascending input from LC to cortex modulates belief updating in anterior cingulate cortex (ACC).
In short, we characterise the LC/ NA system within a general theory of brain function. In doing so, we show that contrasting, behaviour-dependent firing patterns are an emergent property of the LC's crucial role in translating prediction errors into an optimal mediation between plasticity and stability.
Original language | English |
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Article number | e1006267 |
Journal | PLoS Computational Biology |
Volume | 15 |
Issue number | 1 |
DOIs | |
Publication status | Published - 4 Jan 2019 |
Research Groups and Themes
- Anaesthesia Pain and Critical Care
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Dive into the research topics of 'Locus Coeruleus tracking of prediction errors optimises cognitive flexibility: An Active Inference model'. Together they form a unique fingerprint.Student theses
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Theoretical, electrophysiological and optogenetic interrogation of Locus Coeruleus contributions to cognition
Sales, A. C. (Author), Pickering, A. E. (Supervisor), Jones, M. W. (Supervisor) & Moran, R. J. (Supervisor), 24 Mar 2020Student thesis: Doctoral Thesis › Doctor of Philosophy (PhD)
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Profiles
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Professor Anthony Edward Pickering
- School of Physiology, Pharmacology & Neuroscience - Professor of Neuroscience and Anaesthesia
- Bristol Neuroscience
Person: Academic , Member