Fig. 2.

Prefrontal activity interacts with self-control exertion and motivation. (a) Based on the contrast “correct incongruent vs correct congruent trials” during performance of the Stroop task, an interaction cluster was found of which 80% lay within the IFG, and 20% within the middle frontal cortex [P(uncorrected) < 0.001]. Brain activity in this area is commonly associated with inhibition of dominant response tendencies (Derrfuss et al., 2005; Nee et al., 2007). Activation is superimposed on a canonical normalized image. (b) Activity in this cluster (arbitrary units), corrected for the covariate Stroop performance. Within the regular motivation condition, a depletion-related reduction of activity can be observed. After having exerted self-control, highly motivated depleted participants activate the area more strongly than participants in the other conditions. Error bars indicate ±SEM; *P < 0.05, **P < 0.01, ***P < 0.001.