A central future direction motivated by these findings is to investigate the functional aspects and neural generators of theta and delta during response inhibigion. For example, now that both theta and delta have been shown to be sensitive to response inhibition, it would be interesting to assess the role and coordination of each in terms of behavioral indices, such as reaction time and accuracy. In terms of neuronal generators, while an a priori hypothesis of ACC sources underlying theta activity would be expected from previous reports detailing the sources of no-go N2 and other medial-frontal negativities, as mentioned above, the neuronal generators of delta and the no-go P3 are less clear. Another measure of interest, not evaluated in the present study, is phase-synchrony (Aviyente et al, 2011; Tallon-Baudry et al. 1996; Lachaux et al., 1999). This includes intertrial phase synchrony (i.e., quantification of the consistency of brief responses from trial to trial at a single electrode) and inter-regional phase synchrony (i.e., indexing short- and long-range functional integration via between-channel synchronization within trials). Such work could reveal whether theta and delta
