Validity expectancies shape the interplay of cueing and task demands during inhibitory control associated with right inferior frontal regions.

Abstract

The neural mechanisms of inhibitory control have extensively been studied, including the effects of demands to engage in inhibitory control and the effects of valid and invalid cueing. Theoretical considerations, however, suggest that the aforementioned factors exert joined effects on response inhibition processes that are further modulated by the subject's experience about the reliability of cue stimuli during response inhibition processes. To examine the underlying neurophysiological processes of these interactive effects we combined EEG signal decomposition with sLORETA source localization. We show that response inhibition performance is modulated by interactive effects between (1) cue information/validity, (2) demands on inhibitory control processes and (3) the subject's experience that cue information is valid/invalid during response inhibition processes. Only if demands on inhibitory control processes are high and when participants acquainted the experience that cue information is very likely to be valid, invalid cue information compromised response inhibition performance. The neurophysiological data show that processes in the N2 time window, likely reflecting braking processes, but not stimulus-related processes during response inhibition, are modulated. It seems that braking processes cannot be sufficiently deployed if cue information that has been experienced to be highly valid turns out to be invalid in situations placing high demands on inhibitory control. Source localization data reveals that the interactive effects of the examined factors specifically modulate processes in the right inferior frontal gyrus (BA47). This provides electrophysiological evidence that the rIFG is a hub region integrating different factors modulating inhibitory control.