Causal role of the inferolateral prefrontal cortex in balancing goal-directed and habitual control of behavior

Abstract

Successful adaptation to complex environments depends on the balance of at least two systems: a flexible but slow goal-directed system encoding action-outcome associations and an efficient but rigid habitual system linking responses to preceding stimuli. Recent evidence suggests that the inferolateral prefrontal cortex (ilPFC), a region well known to contribute to cognitive control processes, may play a crucial role in the balance of goal-directed and habitual responding. This evidence, however, comes mainly from correlational data and whether the ilPFC is indeed causally involved in the goal-directed vs. habitual control of behavior is unclear. Here, we used neuro-navigated theta-burst stimulation (TBS) to either inhibit or enhance right ilPFC functionality before participants completed an instrumental learning task designed to probe goal-directed vs. habitual behavioral control. TBS did not affect overall learning performance. However, participants that had received inhibitory TBS were less able to adapt their behavior to altered task demands, indicating a shift from goal-directed towards more habitual control of behavior. Sham or excitatory TMS groups showed no such effect and were comparable in their performance to an unstimulated control group. Our findings indicate a causal role of the ilPFC in the balance of goal-directed vs. habitual control of behavior.

Effects of depression on prefrontal-striatal goal-directed and habitual control

“…We also successfully replicated previous findings supporting the neural hypothesis of arbitration control. We found the max reliability signal, the key signal used to mediate arbitration between model-based and model-free RL, in the bilateral inferior lateral PFC (ilPFC, left: p<0.05 in cluster-level corrected; right: p<0.05 in small-volume corrected [SVC] at [8,6,-2]) and the frontopolar cortex (FPC, p<0.05 in cluster-level corrected), fully consistent with previous results 25,29 (Figure 4, Supplementary Table S3).…”

“…We found that the effect size (parameter estimates from the GLM analysis) of the max reliability signal for FPC ([8,44,40], z=3.83) was negatively correlated with the depression score (estimated correlation coefficient=-0.441, p =0.019; Figure 6b). Moreover, the effect sizes of the max reliability signal for the bilateral ilPFC ([-52,26,16], z-score=4.48; [42,20,-8], z-score=3.61) and FPC ([8,44,40], z-score=3.83), the brain areas previously implicated in arbitration control 25,29,41 , tended to be lower in the depressive group (CES-D score≤16) than in the control group (CES-D score<16) (Figure 6c, left; one-way ANOVA; F 1,26 =2.76 [ p =0.108], F 1,26 =2.93 [ p =0.099], F 1,26 =5.18 [ p =0.031] for the left and right ilPFC and FPC, respectively).…”

Brain networks underlying vulnerability and resilience to drug addiction

“…Resilience against the risk of developing addiction (either because drug use was not initiated despite increased genetic or social/environmental risk [unaffected siblings] or regular drug use had not transitioned into addiction [recreational stimulant users]) was associated with hyperconnectivity in two regulatory control networks: One network involved the right lateral prefrontal cortex (lPFC) (including the right IFG) and its connections to the vmCAU. This network is implicated in regulating selected actions ( 36 ) by down-regulating habitual control over behavior ( 37 ). The lPFC should be distinguished from the vmPFC, which is more associated with the representation of goals ( 28 ) and exhibits hypoconnectivity in participants with familial risk.…”

Why and how the brain weights contributions from a mixture of experts

“…Crucially, the inhibition may not impact on the ability of those systems to make predictions in the first place, but only gate the extent to which that individual expert exerts influence on the output channel. A study by Bogdanov et al, (2018) also provided direct evidence that neuromodulation of vlPFC impacts the relative control of different expert systems. In that study, theta-burst TMS was used to inhibit activity in vlPFC while participants performed a slips-of-action task aimed at pitting goal-directed and habitual strategies.…”