The impact of sleep quality on resting-state functional connectivity

This study investigates the impact of natural sleep quality on the subsequent day's resting-state functional MRI (rsfMRI) connectivity patterns.

Fourteen healthy female subjects participated in two sets of tests that included sleep assessments and MRI scans across two consecutive days. Sleep quality was objectively measured using a portable EEG monitor in the participant's home environment.

Prior sleep quality affected connectivity within the default mode network (DMN) and the salience network (SN), and between the DMN and SN. Specifically, changes in the wake after sleep onset (WASO) index were correlated with changes in the connectivity between the DMN and SN. An increase in the spindle duration (SpD) index was found to be related to an increase in connectivity within the SN. Subjects that had large changes in connectivity tended to have substantial changes in WASO between the two measurements. In contrast, even though there may have been a substantial change in connectivity for a particular subject, the accompanying change in SpD was relatively small.

The results suggest that the WASO index is correlated with the DMN-SN inter-connectivity, with the observed alteration in connectivity potentially arising from day-to-day variations in the index. In contrast, changes in connectivity associated with the SpD index may reflect differences between individuals rather than daily fluctuations.