PT - JOURNAL ARTICLE AU - Sara Jahfari AU - Frederick Verbruggen AU - Michael J. Frank AU - Lourens J. Waldorp AU - Lorenza Colzato AU - K. Richard Ridderinkhof AU - Birte U. Forstmann TI - How Preparation Changes the Need for Top–Down Control of the Basal Ganglia When Inhibiting Premature Actions AID - 10.1523/JNEUROSCI.0902-12.2012 DP - 2012 Aug 08 TA - The Journal of Neuroscience PG - 10870--10878 VI - 32 IP - 32 4099 - http://www.jneurosci.org/content/32/32/10870.short 4100 - http://www.jneurosci.org/content/32/32/10870.full SO - J. Neurosci.2012 Aug 08; 32 AB - Goal-oriented signals from the prefrontal cortex gate the selection of appropriate actions in the basal ganglia. Key nodes within this fronto-basal ganglia action regulation network are increasingly engaged when one anticipates the need to inhibit and override planned actions. Here, we ask how the advance preparation of action plans modulates the need for fronto-subcortical control when a planned action needs to be withdrawn. Functional magnetic resonance imaging data were collected while human participants performed a stop task with cues indicating the likelihood of a stop signal being sounded. Mathematical modeling of go trial responses suggested that participants attained a more cautious response strategy when the probability of a stop signal increased. Effective connectivity analysis indicated that, even in the absence of stop signals, the proactive engagement of the full control network is tailored to the likelihood of stop trial occurrence. Importantly, during actual stop trials, the strength of fronto-subcortical projections was stronger when stopping had to be engaged reactively compared with when it was proactively prepared in advance. These findings suggest that fronto-basal ganglia control is strongest in an unpredictable environment, where the prefrontal cortex plays an important role in the optimization of reactive control. Importantly, these results further indicate that the advance preparation of action plans reduces the need for reactive fronto-basal ganglia communication to gate voluntary actions.