8 - The role of vigilance in resting-state functional MRI

Abstract

Resting-state fMRI (rsfMRI) has gained widespread adoption as an approach for studying the human brain. However, interpretation of the rsfMRI signal and derived metrics can be complicated by the relative lack of constraints on a subject’s cognitive state during the rsfMRI experiment. In the absence of an engaging cognitive task, a subject’s state of vigilance can vary considerably both within a rsfMRI scan and between different scans. There is a growing appreciation that variations in vigilance are a significant contributor to the rsfMRI signal and can affect a range of rsfMRI metrics, such as measures of signal amplitude and functional connectivity. Unless adequately accounted for, these variations can lead to the incorrect interpretation of rsfMRI metrics, especially in the presence of factors, such as disease and medication use, that are known to affect vigilance. A greater understanding of the role of vigilance in rsfMRI studies can therefore play an important role in improving the interpretation of rsfMRI studies.