Goal-oriented and habitual decisions: Neural signatures of model-based and model-free learning

TLDR

Human decision‑making relies on a slow, deliberative model‑based process and a rapid habitual model‑free process, yet the shared neural activity between them remains unclear. The study aimed to identify the concordant neural activity associated with model‑based and model‑free learning across reward‑related paradigms. To achieve this, the authors performed quantitative meta‑analyses of functional magnetic resonance imaging experiments. The analyses revealed concordant ventral striatal activation for both processes, with model‑based learning additionally engaging medial prefrontal and orbital frontal cortices, and model‑free learning selectively activating the left globus pallidus and right caudate head, indicating overlapping yet distinct neural substrates.

Abstract

Human decision-making is mainly driven by two fundamental learning processes: a slow, deliberative, goal-directed model-based process that maps out the potential outcomes of all options and a rapid habitual model-free process that enables reflexive repetition of previously successful choices. Although many model-informed neuroimaging studies have examined the neural correlates of model-based and model-free learning, the concordant activity among these two processes remains unclear. We used quantitative meta-analyses of functional magnetic resonance imaging experiments to identify the concordant activity pertaining to model-based and model-free learning over a range of reward-related paradigms. We found that: 1) both processes yielded concordant ventral striatum activity, 2) model-based learning activated the medial prefrontal cortex and orbital frontal cortex, and 3) model-free learning specifically activated the left globus pallidus and right caudate head. Our findings suggest that model-free and model-based decision making engage overlapping yet distinct neural regions. These stereotaxic maps improve our understanding of how deliberative goal-directed and reflexive habitual learning are implemented in the brain.