Figure 6.
Expression of the speed-selectivity trade-off during stop trials. A, The trade-off reflects a dynamic focus on speeded or selective inhibition in Informed relative to Uninformed stop trials. We asked whether any regions modulated their activity to reflect this trade-off. Based on how we defined the trade-off (see Materials and Methods) one would predict that regions underlying speeded (but nonselective) inhibition have a negative coefficient in the Uninformed, or a positive coefficient in the Informed condition. In a whole-brain analysis we observed a cluster in the Trade-offInformed-stop > Trade-offUninformed-stop contrast corresponding to right dlPFC (left). Extraction of the coefficients showed that this cluster specifically promoted speeded (but nonselective) inhibition during Informed, but not Uninformed, inhibition (right). Results visualized in MRIcron at p < 0.001 uncorrected. B, The putamen, SMA/pre-SMA, and STN showed the same effect as the cluster in Figure 6A, linking them to speeded inhibition. Of these, the SMA/pre-SMA and putamen mediated fast inhibition only in Informed trials, whereas the STN mediated fast inhibition only in Uninformed trials. Error bars indicate SEM. a.u., arbitrary units; S, superior; I, inferior; P, posterior; L, left; R, right; A, anterior.