The architecture of cortico-basal ganglia pathways allows for many routes to inhibit a planned action: the hyper-direct pathway performs fast action cancellation and the indirect pathway competitively constrains execution signals from the direct pathway. We present a novel model, principled off of basal ganglia circuitry, that differentiates control dynamics of reactive stopping from intrinsic no-go decisions. Using a nested diffusion model, we show how reactive braking depends on the state of an execution process. In contrast, no-go decisions are best captured by a failure of the execution process to reach the decision threshold due to increasing constraints on the drift rate. This model accounts for both behavioral and fMRI responses during inhibitory control tasks better than alternative models. The advantage of this framework is that it allows for incorporating the effects of context in reactive and proactive control into a single unifying parameter, while distinguishing action cancellation from no-go decisions.
Human subjects: Neurologically healthy adults were recruited from the local university population. All procedures were approved by the local institutional review board at Carnegie Mellon University. All research participants provided informed consent to participate in the study and consent to publish any research findings based on their provided data.
- Michael J Frank, Brown University, United States
© 2015, Dunovan et al.
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