Reduced model-based control in gambling disorder despite seemingly intact neural value and task structure
Angela Brands1, Kilian Knauth1,2, David Mathar1
11Department of Psychology, Biological Psychology, University of Cologne, Germany.
Background:
Disordered gambling has been linked to impairments in goal-directed (model-based) control and reinforcement learning.
Methods:
Here we investigated the potential neural basis of this impairment using a sequential reinforcement learning task (modified two-step-task), computational modeling, and functional magnetic resonance imaging (fMRI) in individuals exhibiting symptoms of disordered gambling (GD) and matched healthy controls (HC, n = 30 per group).
Results:
Model-agnostic analyses replicated the effects of reduced performance and reduced model-based control in the gambling group, both in terms of choice and response time effects. Computational modeling of choice behavior confirmed that this effect was due to reduced model-based control in the gambling group. Analyses of choices and response times using drift diffusion modeling revealed a more complex pattern, where behavioral impairments in the gambling group were linked to changes across several parameters reflecting drift rate modulation and asymptote, as well as non-decision time. Despite these pronounced behavioral differences, the gambling group exhibited largely intact neural effects related to the task transition structure, reward feedback and trial-to-trial behavioral adjustments.
Discussion:
Results are discussed with respect to current neurocomputational models of behavioral dysregulation in disordered gambling.
