%0 Journal Article %J Psychol Sci %D 2017 %T Cost-Benefit Arbitration Between Multiple Reinforcement-Learning Systems. %A Kool, Wouter %A Samuel J Gershman %A Fiery A Cushman %X

Human behavior is sometimes determined by habit and other times by goal-directed planning. Modern reinforcement-learning theories formalize this distinction as a competition between a computationally cheap but inaccurate model-free system that gives rise to habits and a computationally expensive but accurate model-based system that implements planning. It is unclear, however, how people choose to allocate control between these systems. Here, we propose that arbitration occurs by comparing each system's task-specific costs and benefits. To investigate this proposal, we conducted two experiments showing that people increase model-based control when it achieves greater accuracy than model-free control, and especially when the rewards of accurate performance are amplified. In contrast, they are insensitive to reward amplification when model-based and model-free control yield equivalent accuracy. This suggests that humans adaptively balance habitual and planned action through on-line cost-benefit analysis.

%B Psychol Sci %V 28 %P 1321-1333 %8 2017 Sep %G eng %N 9 %R 10.1177/0956797617708288