When flanker meets the n-back: What EEG and pupil dilation data reveal about the interplay between the two central-executive working memory functions inhibition and updating

We investigated the interplay between inhibition and updating, two executive working memory (WM) functions. We applied a novel task paradigm consisting of flanker stimuli presented within an n-back task and studied the interaction between inhibitory demands and load on WM updating using behavioral measures, EEG, and pupil dilation. In contrast to studies that examine the interaction between inhibitory demands and load on WM storage components, the current task paradigm allowed testing the interaction between the executive WM components updating and inhibition. We found a reduced flanker interference effect for the highest (2-back) updating load condition compared to lower updating load conditions on most measures. We interpret these findings as indicating that inhibitory control and WM updating are closely intertwined executive functions. Increased load on updating seemed to result in an overall more activated attentional network thus enhancing inhibitory control, such that task performance is less susceptible to distracting information.