The conditional routing model, adapted from Stocco et al. (2014). In this figure, Side 1 represents a prototypical situation, where prefrontal cortex (PFC) is receiving multiple concurrent signals. In this situation, the strongest concurrent signal (from region B) is most likely to affect the PFC (hence the figure shows the impact of connection B in the prefrontal cortex). Side 2 exemplifies the role of the basal ganglia, which serves as a mechanism to modify cortical pathways. In this case, the basal ganglia strengthen the signal particularly from area C (hence the figure features the impact of connection C).