Self-Reported Sleep Quality Across Age Modulates Resting-State Functional Connectivity in Limbic and Fronto-Temporo-Parietal Networks: An Exploratory Cross-Sectional fMRI Study

Abstract

Sleep problems are increasingly present in the general population at any age, and they are frequently concurrent with-or predictive of-memory disturbances, anxiety, and depression. In this exploratory cross-sectional study, 54 healthy participants recruited in Naples (Italy; 23 females; mean age = 37.1 years, range = 20-68) completed the Pittsburgh Sleep Quality Index (PSQI) and a neurocognitive assessment concerning both verbal and visuospatial working memory as well as subjective measures of anxiety and depression. Then, 3T fMRI images with structural and resting-state functional sequences were acquired. A whole-brain seed-to-seed functional connectivity (FC) analysis was conducted by contrasting good (PSQI score <5) vs. bad (PSQI score ≥5) sleepers. Results highlighted FC differences in limbic and fronto-temporo-parietal brain areas. Also, bad sleepers showed an anxious/depressive behavioural phenotype and performed worse than good sleepers at visuospatial working-memory tasks. These findings may help to reveal the effects of sleep quality on daily-life cognitive functioning and further elucidate pathophysiological mechanisms of sleep disorders.

Keywords: anxiety; depression; functional connectivity; subjective sleep quality; working memory.

Figure 1

First-level functional connectivity (FC) analysis. 3D graphical representation of the first-level whole-brain seed-to-seed FC analysis’s results (Table 1), which shows the FC differences we found in bad sleepers (i.e., participants with a PSQI score ≥5) as compared to good sleepers (i.e., participants with a PSQI score <5). FC reductions are depicted in blue, while FC increases are illustrated in red.

Figure 2

Between-network regression-based functional connectivity analysis. 3D graphical representation of the second-level, regression-based, between-network functional connectivity analysis’ results. FC hyperconnectivity between the Salience network (peak seed: right SMG; on the left in red) and the Frontoparietal network (peak seed: Posterior Parietal Cortex; on the left in blue) positively correlates with participants’ PSQI scores (scatter plot on the right; the x-axis represents the distribution of PSQI scores while the y-axis represents the functional connectivity value in the seeds).