PT  - JOURNAL ARTICLE
AU  - Kyle Dunovan
AU  - Timothy Verstynen
TI  - Dual learning mechanisms drive adaptive inhibitory control
AID  - 10.1101/153676
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 153676
4099  - http://biorxiv.org/content/early/2017/06/22/153676.short
4100  - http://biorxiv.org/content/early/2017/06/22/153676.full
AB  - Goal-directed behavior requires integrating action selection processes with learning systems that adapt control using environmental feedback. These functions intersect in the basal ganglia (BG), which has at least two targets of plasticity: a dopaminergic modulation of striatal pathways and cortical modulation of the subthalamic nucleus (STN). Dual learning mechanisms suggests that feedback signals have a multifaceted impact on BG-dependent decisions. Using a hybrid of accumulation-to-bound decision models and reinforcement learning, we modeled the performance of humans in a stop-signal task where participants (N=75) learned the prior distribution of the timing of a stop signal through trial-and-error feedback. Changes in the drift-rate of the action execution process were driven by errors in action timing, whereas adaptation in the boundary height served to increase caution following failed stops. These findings highlight two interactive learning mechanisms for adapting the control of goal-directed actions based on dissociable dimensions of feedback error.