Does phasic dopamine release cause policy updates?

Autor: Carter F; Department of Psychology, Concordia University, Montreal, Quebec, Canada.; Montreal Institute for Learning Algorithms, Université de Montréal, Montreal, Quebec, Canada., Cossette MP; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Trujillo-Pisanty I; Department of Psychology, Concordia University, Montreal, Quebec, Canada.; Department of Psychology, Langara College, Vancouver, British Columbia, Canada., Pallikaras V; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Breton YA; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Conover K; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Caplan J; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Solis P; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Voisard J; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Yaksich A; Department of Psychology, Concordia University, Montreal, Quebec, Canada., Shizgal P; Department of Psychology, Concordia University, Montreal, Quebec, Canada.
Jazyk: angličtina
Zdroj: The European journal of neuroscience [Eur J Neurosci] 2024 Mar; Vol. 59 (6), pp. 1260-1277. Date of Electronic Publication: 2023 Dec 01.
DOI: 10.1111/ejn.16199
Abstrakt: Phasic dopamine activity is believed to both encode reward-prediction errors (RPEs) and to cause the adaptations that these errors engender. If so, a rat working for optogenetic stimulation of dopamine neurons will repeatedly update its policy and/or action values, thus iteratively increasing its work rate. Here, we challenge this view by demonstrating stable, non-maximal work rates in the face of repeated optogenetic stimulation of midbrain dopamine neurons. Furthermore, we show that rats learn to discriminate between world states distinguished only by their history of dopamine activation. Comparison of these results to reinforcement learning simulations suggests that the induced dopamine transients acted more as rewards than RPEs. However, pursuit of dopaminergic stimulation drifted upwards over a time scale of days and weeks, despite its stability within trials. To reconcile the results with prior findings, we consider multiple roles for dopamine signalling.
(© 2023 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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