Intentional inhibition: how the "veto-area" exerts control.

One important aspect of self-control is refraining voluntarily from already planned behavior, by a final intervention before commitment to action. Despite its crucial role in human existence, and clear social implications, this aspect of self-control has proved hard to study experimentally. One recent study used a perceptual timing paradigm to identify specific activations in the dorsal fronto-median cortex (dFMC) associated with voluntary inhibition of action (Brass and Haggard 2007: J Neurosci 27:9141-9145). Here, we extend this work in two important new directions. First, we developed a more naturalistic task that gives participants a strong reason to inhibit or to execute actions, and therefore involves self-control in the sense of voluntary inhibition of prepotent impulsive responses. Second, we investigated the relation between dFMC and other cognitive-motor areas using effective connectivity analysis. We show that dFMC is activated when inhibiting prepared responses to external events. Moreover, its effective connectivity suggests that it allows intentional inhibition of action through top-down inhibition of premotor areas. This view of dFMC is consistent with a new view of self-control as a key stage in a cognitive-motor interface. 2008 Wiley-Liss, Inc.