Examining First Night Effect on Sleep Parameters with hd-EEG in Healthy Individuals

Abstract

Difficulty sleeping in a novel environment is a common phenomenon that is often described as the first night effect (FNE). Previous works have found FNE on sleep architecture and sleep power spectra parameters, especially during non-rapid eye movement (NREM) sleep. However, the impact of FNE on sleep parameters, including local differences in electroencephalographic (EEG) activity across nights, has not been systematically assessed. Here, we performed high-density EEG sleep recordings on 27 healthy individuals on two nights and examined differences in sleep architecture, NREM (stages 2 and 3) EEG power spectra, and NREM power topography across nights. We found higher wakefulness after sleep onset (WASO), reduced sleep efficiency, and less deep NREM sleep (stage 3), along with increased high-frequency NREM EEG power during the first night of sleep, corresponding to small to medium effect sizes (Cohen’s d ≤ 0.5). Furthermore, study individuals showed significantly lower slow-wave activity in right frontal/prefrontal regions as well as higher sigma and beta activities in medial and left frontal/prefrontal areas, yielding medium to large effect sizes (Cohen’s d ≥ 0.5). Altogether, these findings suggest the FNE is characterized by less efficient, more fragmented, shallower sleep that tends to affect especially certain brain regions. The magnitude and specificity of these effects should be considered when designing sleep studies aiming to compare across night effects.

Validation of the relationship between rapid eye movement sleep and sleep‐related erections in healthy adults by a feasible instrument Fitbit Charge2

“…This is consistent with the first‐night effect proposed by some authors, where most NPTR parameters are better on the second night than on the first night 51 . Interestingly, the first‐night effect also exists in sleep monitoring 52 . And many studies have shown that monitoring by two nights can effectively avoid false abnormal results because of the first‐night effect 53 …”

“…51 Interestingly, the first-night effect also exists in sleep monitoring. 52 And many studies have shown that monitoring by two nights can effectively avoid false abnormal results because of the first-night effect. 53 It is now widely accepted by scholars that the etiology of ED is usually multifaceted.…”

The First-Night Effect on the Instability of Stage N2: Evidence from the Activity of the Central and Autonomic Nervous Systems

“…Second, we only used six electrodes to record the whole-night EEG data, such that EEG activation could not be mapped extremely accurately in terms of both spatial and temporal resolution. In a future study, it would be quite interesting to add more electrodes to collect data during sleep, which may provide more information on the FNE; for instance, HD-EEG could be used to localize brain areas that are activated differently [ 38 ], and potential changes in EEG activation indexes related to the FNE could be investigated simultaneously.…”

Phase-amplitude coupling of NREM sleep oscillations is unaffected by pre-sleep learning but related to overnight memory gains depending on the declarative learning paradigm

“…The available literature suggests that neural oscillations may show less night-to-night fluctuation, however within-subject variability of gross sleep architecture and brain oscillations has yet to be systematically and statistically compared. Nonetheless, significantly lower slow wave activity in frontal regions (Mayeli et al, 2022), as well as an interhemispheric asymmetry of slow wave activity in brain networks such as the default mode network (Tamaki et al, 2016) have been shown to fluctuate. These results have also extended to higher sigma and beta activities in medial and left prefrontal areas (Mayeli et al, 2022).…”