Differences in resting state functional connectivity in striatal and frontal networks associated with task-behaviour...

This study aims to neurobiologically validate a newly developed gamified version of the modified two-stage task. The two-stage decision-making task is used to measure model-free and model-based decision strategies (commonly considered analogous to habitual and goal-directed decisions, respectively) with a weighting parameter (w) outcome variable indicating to what degree task behaviour is model-free or model-based. Our task is based on the Kool et al. (2016) modified version of the two-stage task, which has a simplified structure and has been designed with animations and narrative structure to improve engagement, understanding, and enjoyment of the task. Using resting state functional connectivity (rsFC) in a community sample of healthy adults (N = 48), we investigated if the weighting parameter (w) is associated with differences in rsFC in networks related to habitual and/or goal-directed decision-making, using seed-based analyses. Lower (w) rates (i.e. more habitual task behaviour) were associated with reduced rsFC between both left and right NAc projections to the left supramarginal gyrus, as well as reduced rsFC between left thalamus and the precuneous. This is consistent with research showing reductions in fronto-striatal network connectivity in obsessive-compulsive disorder, eating disorder, and gaming - conditions commonly assumed to be related to excessive habit-formation. Additionally, increased rsFC projecting from frontal pole to occipital pole was associated with higher (w) (i.e. more goal-directed task behaviour), whereas rsFC connectivity between right inferior frontal gyrus and left superior frontal gyrus as well as between left superior frontal gyrus and right frontal pole were associated with lower (w). These results indicate that task behaviour elicited by our gamified version of the two-stage decision-making task is reflecting differences in functional connectivity in both striatal and frontal networks when the brain is at rest. This is a promising indicator that our gamified two-stage decision task is indeed measuring differences related to neural processes in networks related to habitual and goal-directed decision-making processes.