The dorsal medial frontal cortex is sensitive to time on task, not response conflict or error likelihood.
Grinband J, Savitskaya J, Wager TD, Teichert T, Ferrera VP, Hirsch J. The dorsal medial frontal cortex is sensitive to time on task, not response conflict or error likelihood. Neuroimage. 2011 Jul 15; 57(2):303-11.