Effective Connectivity Reveals Important Roles for Both the Hyperdirect (Fronto-Subthalamic) and the Indirect (Fronto-Striatal-Pallidal) Fronto-Basal Ganglia Pathways during Response Inhibition

• DOI: 10.1523/jneurosci.5253-10.2011
• Publication Date: 2011-05-04T17:01:28Z
• Authors: Sara Jahfari; Lourens Waldorp; Wery P. M. van de...; H. Steven Scholte; K. Richard Ridder...; Birte U. Forstmann
• Keywords: Subthalamic Nucleus; Inferior frontal gyrus; Action selection; Caudate nucleus; Stop signal

Fronto-basal ganglia pathways play a crucial role in voluntary action control, including the ability to inhibit motor responses. Response inhibition might be mediated via fast hyperdirect pathway connecting right inferior frontal gyrus (rIFG) and presupplementary area (preSMA) with subthalamic nucleus or, alternatively, indirect between cortex caudate. To test relative contribution of these two inhibitory we applied an innovative quantification method for effective brain connectivity. Functional magnetic resonance imaging data were collected from 20 human participants performing Simon interference task occasional stop signal. A single right-lateralized model involving both best explained pattern activation on trials. Notably, overall connection strength this combined was highest successfully inhibited Inspection relationship behavior values revealed that inhibitors showed increased connectivity rIFG caudate (rCaudate), whereas slow associated preSMA rCaudate. In compliance, strengths into rCaudate correlated negatively. If failed stop, magnitude experienced (Simon effect), but not stopping latency, predictive hyperdirect–indirect connections. Together, present results suggest act together implement response inhibition, performance control fronto-basal connections points toward top-down mechanism underlies control.