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Updated: Mar 3, 2026

Measuring Neural Mechanisms Underlying Sleep-Dependent Memory Consolidation During Naps in Early Childhood
Published on: October 2, 2019
Cardiac autonomic activity during daytime nap in young adults
Nicola Cellini1, Jacopo Torre1, Luciano Stegagno1
1Department of General Psychology, University of Padova, Padova, Italy.
Abstract:
The current study investigated both sympathetic and vagal autonomic patterns during a daytime sleep in 25 healthy adults (23.2 ± 2.4 years). Pre-ejection period (PEP; related inversely to beta-adrenergic sympathetic activity), the interval between consecutive R-waves (RR) and frequency-domain heart rate variability (HRV) were computed during pre-nap wakefulness and undisturbed sleep stages. Results showed sleep-related changes in RR and HRV measures, whereas PEP decreased significantly from pre-nap to sleep, showing no differences across sleep stages. Moreover, pre-nap PEP and HFnu (the normalized unit of the high-frequency component of HRV) were associated negatively with sleep latency and wake after sleep onset. These results indicate a marked autonomic output reduction during daytime sleep, with different stage-dependent fluctuations for sympathetic and vagal activity. Importantly, pre-nap autonomic activity seems to modulate subsequent sleep quality.
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