Model-based and model-free pain avoidance learning. (5th May 2018)

• Record Type: Journal Article
• Authors: Wang, Oliver; Lee, Sang Wan; O'Doherty, John; Seymour, Ben; Yoshida, Wako
• Is Part Of: Brain and neuroscience advances. Volume 2(2018)
• Publication Date: 2018-05-05
• Subjects: Decision-making -- pain avoidance -- reinforcement learning -- uncertainty; Brain -- Periodicals; Neurosciences -- Periodicals; Brain; Nervous System; Brain; Neurosciences; Periodicals; Periodical; 616.8
• DOI: 10.1177/2398212818772964
• Languages: English
• ISSNs: 2398-2128

Abstract

Background: While there is good evidence that reward learning is underpinned by two distinct decision control systems – a cognitive 'model-based' and a habitbased 'model-free' system, a comparable distinction for punishment avoidance has been much less clear.Methods: We implemented a pain avoidance task that placed differential emphasis on putative model-based and model-free processing, mirroring a paradigm and modelling approach recently developed for reward-based decision-making. Subjects performed a two-step decision-making task with probabilistic pain outcomes of different quantities. The delivery of outcomes was sometimes contingent on a rule signalled at the beginning of each trial, emulating a form of outcome devaluation.Results: The behavioural data showed that subjects tended to use a mixed strategy – favouring the simpler model-free learning strategy when outcomes did not depend on the rule, and favouring a model-based when they did. Furthermore, the data were well described by a dynamic transition model between the two controllers. When compared with data from a reward-based task (albeit tested in the context of the scanner), we observed that avoidance involved a significantly greater tendency for subjects to switch between model-free and model-based systems in the face of changes in uncertainty.Conclusion: Our study suggests a dual-system model of pain avoidance, similar to but possibly more dynamically flexible than reward-based decision-making.