Moment-to-moment fluctuations in fMRI amplitude and inter-region coupling are predictive of inhibitory performance

摘要

We investigated how moment-to-moment fluctuations in fMRI amplitude and inter-regional coupling are linked to behavioral performance during a stop-signal task. To quantify the relationship between single-trial amplitude and behavior on a trial-by-trial basis, we modeled the probability of successful inhibition as a function of response amplitude via logistic regression analysis. At the group level, significant logistic slopes were observed in, among other regions, the inferior frontal gyrus (IFG), caudate, and putamen, all bilaterally. Furthermore, we investigated how trial-by-trial fluctuations in responses in “attentional regions” covaried with fluctuations in “inhibition-related” regions. The coupling between several fronto-parietal attentional regions and the right IFG increased during successful vs. unsuccessful performance, suggesting that efficacious network interactions are important in determining behavioral outcome during the stop-signal task. In particular, the link between responses in the right IFG and behavior were moderated by moment-to-moment fluctuations in evoked responses in the left intraparietal sulcus.