bluuebunny/crossref_metadata_2025_split huggingface dataset:
135 One night of mild sleep restriction affects EEG and behavioural measures of vigilance
Authors: Gibbings Aaron , Ray Laura , Berberian Nareg , Zandi Ali Shahidi , Owen Adrian , Comeau Felix , Fogel Stuart 
Published: May 2021

Abstract

Introduction
Much is known about the behavioural and cognitive consequences of chronic sleep loss but relatively little is known about the changes in brain activity associated with reduced vigilance after mild and acute sleep loss. Mild and acute sleep loss is generally thought to be innocuous despite research showing emotional processing, visual attention and behavioural responding are all negatively impacted by even small amounts of sleep loss. The current study investigated behavioural, cognitive, and electrophysiological consequences of mild (i.e., a couple of hours) and acute (i.e., a single night) sleep loss via simultaneous behavioural and physiological measures of vigilance.

Methods
Participants (N = 23; 18 females, Mage = 22 ± 3 years) came into the lab (from ~12 pm to 3 pm) for two testing days after sleeping from 1 am to 6 am (Sleep Restriction), or from 12 am to 9 am (Normally Rested). Brain activity was recorded using electroencephalography (EEG) from 15 scalp derivations, while vigilance was assessed simultaneously using the psychomotor vigilance task (PVT).

Results
Vigilance was reduced in the Sleep Restricted vs. Normally Rested condition, (F(1,22)=9.02, p=0.007). This was exacerbated over the course of performing the PVT, (F(5,110)=8.12, p&lt;0.001). Sleep Restriction also resulted in increased intensity of alpha burst activity compared to the Normally Rested condition (F(1,20)=6.19, p=0.022). Lastly, EEG spectral power differed between restriction sleep conditions across deepening stages of sleep onset, particularly for frequencies that reflect arousal e.g., delta, alpha and beta activity (F(1,20)&gt;5.52, p&lt;0.029).

Conclusion
These results suggest that even a small amount of sleep loss, occurring on only one night significantly reduces vigilance and impacts the physiology of the brain in ways that reflect reduced arousal. Understanding the neural correlates and cognitive processes associated with sleep loss may lead to important advancements in identifying and preventing potentially deleterious or dangerous, sleep-related lapses in vigilance (e.g., in the classroom, workplace), and when lapses in vigilance can be life-threatening (e.g., while driving).
Support (if any):
137 Recovery Dynamics in a Biomathematical Model of Fatigue
Authors: McCauley Mark , McCauley Peter , Van Dongen Hans 
Published: May 2021

Abstract

Introduction
In commercial aviation and other operational settings where biomathematical models of fatigue are used for fatigue risk management, accurate prediction of recovery during rest periods following duty periods with sleep loss and/or circadian misalignment is critical. The recuperative potential of recovery sleep is influenced by a variety of factors, including long-term, allostatic effects of prior sleep/wake history. For example, recovery tends to be slower after sustained sleep restriction versus acute total sleep deprivation. Capturing such dynamics has proven to be challenging.

Methods
Here we focus on the dynamic biomathematical model of McCauley et al. (2013). In addition to a circadian process, this model features differential equations for sleep/wake regulation including a short-term sleep homeostatic process capturing change in the order of hours/days and a long-term allostatic process capturing change in the order of days/weeks. The allostatic process modulates the dynamics of the homeostatic process by shifting its equilibrium setpoint, which addresses recently observed phenomena such as reduced vulnerability to sleep loss after banking sleep. It also differentiates the build-up and recovery rates of fatigue under conditions of chronic sleep restriction versus acute total sleep deprivation; nonetheless, it does not accurately predict the disproportionately rapid recovery seen after total sleep deprivation. To improve the model, we hypothesized that the homeostatic process may also modulate the allostatic process, with the magnitude of this effect scaling as a function of time awake.

Results
To test our hypothesis, we added a parameter to the model to capture modulation by the homeostatic process of the allostatic process build-up during wakefulness and dissipation during sleep. Parameter estimation using previously published laboratory datasets of fatigue showed this parameter as significantly different from zero (p&lt;0.05) and yielding a 10%–20% improvement in goodness-of-fit for recovery without adversely affecting goodness-of-fit for pre-recovery days.

Conclusion
Inclusion of a modulation effect of the allostatic process by the homeostatic process improved prediction accuracy in a variety of sleep loss and circadian misalignment scenarios. In addition to operational relevance for duty/rest scheduling, this finding has implications for understanding mechanisms underlying the homeostatic and allostatic processes of sleep/wake regulation.

Support (if any)
Federal Express Corporation
139 Does Extraversion Predict Subjective Ratings of Sleepiness and Performance During Sleep Deprivation?
Authors: Schneider Ben , Honn Kimberly , Van Dongen Hans 
Published: May 2021

Abstract

Introduction
Repeated exposure to total sleep deprivation (TSD) within individuals has demonstrated task-specific, trait-like individual differences in cognitive impairment and subjective sleepiness. Research has suggested that introversion/extraversion may predict individual vulnerability to TSD. While previous analyses have found that extraversion does not reliably predict objective performance impairment on the psychomotor vigilance test (PVT) during TSD, it is not known whether extraversion may predict individuals’ subjective responses to TSD, including subjective ratings of sleepiness, fatigue, mood, performance, and effort.

Methods
N=21 healthy adults (aged 21-38; 9 women) completed three 4-day/3-night laboratory sessions – each including a baseline night, 36h TSD period, and recovery night –separated by at least 2 weeks each. Two of the sessions were preceded by a week of sleep extension (12h nightly sleep opportunities), while one session was preceded by a week of sleep restriction (6h nightly sleep opportunities), in randomized, counterbalanced order; only the sleep extension sessions are used here. Prior to the experiment, subjects filled out the Eysenck Personality Questionnaire (EPQ), which yielded an extraversion score; one subject did not complete the questionnaire and was excluded from analyses. Every 2h during TSD, subjects completed a 60min neurobehavioral test battery. At the beginning of the test battery, subjects completed the Karolinksa Sleepiness Scale (KSS) and visual analog scales of mood and fatigue (VAS-M and VAS-F). At the end of the test battery, subjects completed self-ratings of their performance (1–7 scale) and effort (1–4 scale). The relationship between extraversion and subjective scores after sleep deprivation (average over last 24h of 36h TSD period) relative to baseline (average over first 12h of TSD period) was analyzed using mixed-effects analysis of covariance, controlling for order, with a random effect over subjects on the intercept.

Results
No significant relationships were observed between extraversion and subjective estimates of sleepiness (KSS, p=0.45), fatigue (VAS-F, p=0.80), mood (VAS-M, p=0.14), performance (p=0.89), and effort (p=0.93).

Conclusion
These results indicate that extraversion is not a reliable predictor of trait-like individual differences in subjective vulnerability to 36h TSD.

Support (if any)
NASA grant NAG9-1161, CDMRP grant W81XWH-20-1-0442
142 Prenatal Sleep Quality and Infant Sleep: A Longitudinal Study
Authors: Burdayron Rebecca , Pennestri Marie-Helene , Keys Elizabeth , Tomfohr-Madsen Lianne , Giesbrecht Gerald 
Published: May 2021

Abstract

Introduction
Poor sleep quality is common during pregnancy and can increase the risk of adverse obstetric and fetal outcomes. Existing research on the association between prenatal sleep and infant sleep is scarce and has focused on other aspects of prenatal sleep such as sleep duration, chronotype, and insomnia symptoms. To our knowledge, no studies have examined the association between prenatal sleep quality and infant sleep outcomes. Thus, this study aimed to investigate whether maternal sleep quality during pregnancy was prospectively associated with infant sleep dimensions, independent of relevant covariates.

Methods
Participants were a subset of 272 mother-infant dyads enrolled in an ongoing cohort study. Maternal prenatal sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) in early to mid- (M gestational age = 15.12 ± 3.56 weeks) and late- (M gestational age = 32.44 ± 0.99 weeks) pregnancy. Mothers completed the Brief Infant Sleep Questionnaire (BISQ) at 3, 6, and 12 months postpartum. The following infant sleep parameters were assessed: sleep duration (day, night, 24-hour), number of night awakenings, and wake after sleep onset. Prenatal depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale (EPDS) at both pregnancy time points. Other covariates included maternal age at enrollment, infant age, parity, and co-sleeping status.

Results
Generalized estimating equations (GEE) models revealed that poorer maternal sleep quality during early-to-mid pregnancy did not significantly predict infant sleep parameters after adjustment for covariates (p &gt; .05). However, in late pregnancy, poorer maternal sleep quality significantly predicted shorter 24-hour sleep duration and longer wake after sleep onset, but not daytime sleep duration, nighttime sleep duration, and number of night awakenings (p &lt; .05).

Conclusion
Study findings advance our understanding of the prospective link between maternal prenatal sleep quality and infant sleep. Results indicate that maternal sleep quality during late gestation may play a role in the development of infant sleep patterns. These findings have important implications for intervention efforts targeting maternal sleep quality during pregnancy. Future research should use objective measures of sleep, such as actigraphy, to better elucidate the effects of prenatal sleep quality on infant sleep outcomes.

Support (if any)
The Canadian Institutes of Health Research (CIHR)
150 Impact of Behavioral Disorders and their Pharmacological Treatment on the Maturational Trajectories of NREM Slow Wave Activity
Authors: Fernandez-Mendoza Julio , Ricci Anna , He Fan , Fang Jidong , Calhoun Susan , Cain Patricia , Vgontzas Alexandros , Liao Duanping , Bixler Edward 
Published: May 2021

Abstract

Introduction
Slow wave activity (SWA) in the delta (0.4-4 Hz) frequency range declines in typically developing (TD) children as they transition to adolescence. However, it remains unknown whether the maturational trajectory of NREM delta power differs between TD youth and those with psychiatric/behavioral disorders.

Methods
We analyzed the sleep EEG of 664 subjects aged 6 to 21 (46.8% female, 24.7% racial/ethnic minority) from the Penn State Child Cohort, of whom 449 were TD, 123 were un-medicated and diagnosed with psychiatric/behavioral disorders, and 92 were medicated with stimulants, anti-depressants, anxiolytics, sedatives and/or anti-psychotics. Multivariable regression models adjusting for sex, race/ethnicity, BMI, AHI and PSG system tested the age-related trajectories of NREM delta power within each diagnostic group.

Results
Delta power in TD and un-medicated youth showed cubic age-related trajectories (both p-cubic&lt;0.05). In TD youth, delta power was highest at age 6.6 and lowest at age 19.9, while in un-medicated youth it was highest at age 8.9 and lowest at age 18.6. The decreasing slope in delta power was 39.7% steeper in un-medicated youth (-22422 ± 5891/year, p&lt;0.01) than TD youth (-16047 ± 2605/year, p&lt;0.01). Delta power in medicated youth showed a distinct linearly decreasing trajectory (-13518 ± 4597/year, p-linear&lt;0.01) from age 6 (highest) to age 21 (lowest).

Conclusion
TD and un-medicated youth with psychiatric/behavioral disorders show SWA trajectories typical of brain maturation biomarkers (e.g., gray matter volume), characterized by a decreasing slope at the onset of puberty that reaches its nadir by late adolescence. However, SWA in un-medicated youth peaks two years later and reaches its nadir a year earlier than in TD youth. Thus, while TD children experience a smooth decline in SWA in the transition to adolescence, those with psychiatric/behavioral disorders experience a faster steep decline. In contrast, SWA in medicated youth appears to be dampened in early childhood and its slope linearly decreases with age. These data suggest that these youth may have a more severe disorder requiring pharmacological treatment, that the latter produces greater cortical arousability reflected in lower SWA power, and/or that psychoactive medications directly impact normal neurodevelopmental processes (e.g., synaptic pruning).

Support (if any)
NIH Awards Number R01MH118308, R01HL136587, R01HL97165, R01HL63772, UL1TR000127
155 Evening blue light exposure, maternal glucose and infant birth weight
Authors: Balserak Bilgay Izci , Hermann Renata , Buhimschi Catalin , Park Chang Gi 
Published: May 2021

Abstract

Introduction
During pregnancy, the use of light-emitting electronic devices before bedtime may contribute to or exacerbate sleep problems. Exposure to blue-wavelength light in particular from these devices may affect sleep by inhibiting melatonin release and causing neurophysiologic arousal which may affect the uterus environment. However, the health consequences of blue-wavelength light on maternal glucose level and fetus development is poorly understood. The purpose of this study was to test the hypothesis that nocturnal blue-light exposure is associated with maternal glucose level and infant’s birth weight.

Methods
A group of pregnant women aged 24-39 years old who wore 7-day actigraphy, and completed questionnaires including Pittsburgh Sleep Quality Index participated in the study. Infant’s birth weight (n=41) and fasting glucose level (n=30) was abstracted from mothers’ medical charts. Blue-wavelength light exposure was obtained from actigraphy recordings. Unadjusted linear regression analyses were performed to determine sleep characteristics that were associated with fasting glucose and infant’s weight (p&lt;0.2). Using infant’s birth weight and fasting glucose as outcome variables, confounding variables were evaluated in full linear regression models as independent variables.

Results
The mean gestational age was 30.66 (Standard Deviation (SD) 3.46) weeks. The mean fasting glucose, infant’s birth weight and gestational age at delivery were 95.73 mg/dL (SD 24.68), 3261 gr (SD 470) and 38.78 (SD 1.69), respectively. In unadjusted analysis, infant birth weight was significantly associated with only blue light value (μW/cm2) (β=76.98, p=0.002) and remained significant (β=78.26, p=0.003) after adjusting for BMI, maternal age and gestational diabetes. Fasting glucose was associated with blue light value (β=2.81, p=0.055) and became significantly associated (β=78.26, p=0.003) after adjusting for sleep duration, parity and gestational diabetes. The coefficient demonstrates that for each unit increase in the evening blue light exposure, there is a 78 gr increase in infant weight after controlling the effect of maternal age, BMI and gestational diabetes.

Conclusion
Evening blue light exposure during mid and late pregnancy may alter maternal glucose regulation and placental nutrient transport to fetus, but these remain to be studied. This study may shed light on future research on the effect of evening light exposure on pregnancy outcomes.

Support (if any)
National Institutes of Health (R00-NR013187)
156 Evening Light-Induced Circadian Phase Shift in Preschool-Aged Children
Authors: Hartstein Lauren , Akacem Lameese , Behn Cecilia Diniz , Stowe Shelby , Wright Kenneth , LeBourgeois Monique 
Published: May 2021

Abstract

Introduction
In adults, exposure to light at night delays the timing of the circadian clock in a dose-dependent manner with intensity. Although children’s melatonin levels are highly suppressed by evening bright light, the sensitivity of young children’s circadian timing to evening light is unknown. This research aimed to establish an illuminance response curve for phase delay in preschool children as a result of exposure to varying light intensities in the hour before bedtime.

Methods
Healthy children (n=36, 3.0 – 4.9 years, 39% males), participated in a 10-day protocol. For 7 days, children followed a strict parent-selected sleep schedule. On Days 8-10, an in-home dim-light assessment was performed. On Day 8, dim light melatonin onset (DLMO) was measured through saliva samples collected in 20-30-min intervals throughout the evening until 1-h past habitual bedtime. On Day 9, children were exposed to a white light stimulus (semi-randomly assigned from 5lx to 5000lx) for 1-h before their habitual bedtime, and saliva was collected before, during, and after the exposure. On Day 10, children provided saliva samples in the evening for 2.5-h past bedtime for a final DLMO assessment. Phase angle of entrainment (habitual bedtime – DLMObaseline) and circadian phase delay (DLMOfinal – DLMObaseline) were computed.

Results
Final DLMO (Day 10) shifted between -8 and 123 minutes (M = 56.1 +/- 33.6 min; negative value = phase advance, positive value = phase delay) compared with DLMO at baseline (Day 8). Raw phase shift did not demonstrate a dose-dependent relationship with light intensity. Rather, we observed a robust phase delay across all intensities.

Conclusion
These data suggest preschoolers’ circadian clocks are immensely sensitive to a large range of light intensities, which may be mechanistically influenced by less mature ophthalmologic features (e.g. clearer lenses, larger pupils). With young children’s ever-growing use of light-emitting devices and evening exposure to artificial lighting, as well as the prevalence of behavioral sleep problems, these findings may inform recommendations for parents on the effects of evening light exposure on sleep timing in early childhood.

Support (if any)
This research was supported with funds from the Eunice Kennedy Shriver National Institute of Child Health & Human Development (R01-HD087707).
157 The Circadian Variation of Sleep in Postmenopausal Women
Authors: Carballo Rafael Perez Medina , Kosmadopoulos Anastasi , Robert Manon , Boivin Diane 
Published: May 2021

Abstract

Introduction
During menopause, 40-60% of women report sleep complaints. Despite the fact that menopause is associated with fluctuations in sex hormones that can affect circadian physiology, the role of circadian factors in sleep disturbances after menopause is not well understood. The present study aims to understand the circadian variation of sleep occurring after menopause.

Methods
Eight healthy postmenopausal women (PMW; 54.8±3.4 years, one taking hormones) without sleep complaints were enrolled and compared to previously-collected data from 12 healthy young women (YW; 25.8±3.4 years) in mid-follicular phase. Following an 8-h baseline sleep period aligned to their habitual sleep times, participants underwent a 48-h (PMW) or 72-h (YW) ultradian sleep-wake cycle procedure (USW) with 60-min wake episodes alternating with 60-min nap opportunities. Sleep was recorded with polysomnography. Circadian parameters (amplitude, phase) of core body temperature (CBT) and sleep were assessed and compared using mixed-effects linear models on the first 48 hours of USW. Sleep parameters, including total sleep time (TST), arousals, sleep onset latency (SOL), stages N1, N2, N3, REM, and wake, were compared between groups during baseline and USW.

Results
PMW presented earlier habitual bedtimes (23:07±00:11 vs 00:13±00:12) and rise-times (07:07±00:11 vs 08:13±00:12) compared to YW (p=0.005). There were no differences in amplitude, phase, or phase angle of CBT. An advanced acrophase of REM sleep (p=0.034) and lower amplitudes of TST, arousals, SOL, N3, and wake, were observed in PMW vs YW (p≤0.05). During baseline, PMW presented more stage N1 (p=0.030) and arousals (p&lt;0.001) than YW. During USW, group effects were observed, with more stage N1 (p=0.007) and N2 (p=0.0007) in PMW vs YW. Significant interactions showed greater TST (p=0.009), shorter SOL (p=0.001), and more arousals (p=0.027) in PMW during the habitual day.

Conclusion
The primary finding in this small group of PMW with no sleep complaints was a general increase in light sleep and arousals across circadian phases. No differences in CBT rhythms were observed, whereas small differences in the circadian variation of TST, N3, and REM sleep were observed. Further studies are needed to clarify the role of circadian processes on sleep in PMW.

Support (if any)
Study supported by the Canadian Institutes of Health Research.
168 Prevalence and Severity of Sleep Disruption Amongst Asylum-Seekers in South Florida
Authors: Jones Sara , Arora Arshia , Brooks Jordan , Easwaran Lavanya , Davis Jenna , Engle Kyrra , Johnson Catherine , Kather Josefina , Nunes Antonio , Radhakrishnan Ramya , Skelton Alexander , Symes Stephen 
Published: May 2021

Abstract

Introduction
While research suggests that asylum-seekers often present with a high level of medical and psychological needs, there is a dearth of research exploring sleep quality in this population, and, accordingly, the role that the sleep medicine community may be able to play in alleviating the suffering of this population. Therefore, this study aims to assess the prevalence of sleep disruption amongst asylum-seekers presenting to a South Florida clinic and to categorize these disruptions according to severity and type.

Methods
This is a cross-sectional study utilizing medical affidavits for asylum seekers in South Florida from 2018-2020 (n=54). Affidavits were reviewed for narrative descriptions of sleep quality and information from validated screeners regarding sleep; demographic information was also collected. Affidavits were excluded if they did not include itemized answers to screening questions.

Results
Out of 54 asylum-seekers (31% male, median age=34.5 years), 72.2% reported sleep disturbance. 38.9% reported nightmares, 66.7% reported insomnia of any type, and 29.6% reported severe insomnia. Asylum-seekers that screened positive for post-traumatic stress disorder (PTSD) were more likely to report ongoing sleep disturbance than asylum-seekers that screened negative for PTSD (p=.004). Sleep disturbance prevalence did not vary significantly by gender identity or country of origin.

Conclusion
This study reveals a high prevalence of sleep disruption amongst asylum-seekers in South Florida. The asylum-seekers in our study were more likely to experience insomnia than nightmares, but many experienced both; sleep disturbance was significantly associated with screening positive for PTSD. Our findings suggest that physicians working with asylum-seekers should ask about sleep quality and offer appropriate care. Directions for further research include investigating how poor sleep quality impacts the health and wellbeing of asylum-seekers.

Support (if any)
None