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1.
Sleep Health ; 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38876932

ABSTRACT

OBJECTIVES: At the peak of COVID-19, adolescent life was disrupted as schools adapted their instructional approaches such as online, in-person, or hybrid instruction. We and others have previously commented on how these shifts facilitated longer, later and (more developmentally appropriate) sleep. Here, we report how sleep contributed to associations between remote instruction and broader academic well-being (e.g., cognitive function, school connectedness, and stress). METHODS: Adolescents from all 50 U.S. states (n = 4068) completed online self-report surveys in fall 2020. Instructional approach was operationalized from fully in-person instruction to fully asynchronous online education. Sleep parameters included sleep timing and duration, sleep disturbances, and sleep-related impairments. Perceived academic well-being was defined as cognitive function, school connectedness, and school-related stress. Sleep and perceived academic well-being are examined across instructional approaches, in their association, and in structural models. RESULTS: Sleep and perceived academic well-being differed between hybrid and online instruction groups. Less variable or disturbed sleep was associated both with in-person instruction, and with positive outcomes in cognitive function, school connectedness, and stress domains. Sleep mediated a substantial portion of variance in perceived academic well-being attributable to instructional approach. CONCLUSION: These data highlight the need to protect both healthy sleep and in-person instruction. Appropriate sleep timing and duration, fewer sleep disturbances and sleep-related impairments accounted for a substantial degree of variance in the association between remote instruction on academic outcomes. While many students experienced "lost learning" because of COVID-19, this study joins a broader discussion of ensuring developmentally appropriate school-start times to support both sleep and achievement.

2.
Sleep ; 47(4)2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38205895

ABSTRACT

STUDY OBJECTIVES: Alcohol consumption before sleep decreases sleep latency, explaining the common use of alcohol as a sleep aid. The full impact of alcohol on sleep architecture is not well understood, particularly the potential cumulative effects of presleep alcohol consumption across consecutive nights. Here, we describe the effects of presleep alcohol on sleep architecture across three consecutive nights. METHODS: Thirty adult participants took part in a crossover, within-participants study consisting of two sets of three consecutive nights of in-lab polysomnography. For each series of nights, participants drank one of the two beverages: a mixer only or a mixer plus alcohol (targeting a BrAC of 0.08 mg/L), ending 1 hour before lights out. Polysomnography (PSG) was used to stage sleep, and standard sleep variables were extracted. Linear mixed-effect analysis and generalized additive modeling were used to examine the effect of alcohol on sleep architecture. RESULTS: Alcohol before sleep increased the rate of slow wave sleep (SWS) accumulation across all three nights and decreased the rate of rapid eye movement (REM) sleep accumulation at the start of each night. Alcohol also decreased the total amount of REM sleep but did not affect the total amount of SWS each night. CONCLUSIONS: These data indicate that drinking alcohol before sleep substantially affects sleep architecture, including changes to the rate of accumulation of SWS and REM sleep. We show that alcohol disrupts normal sleep architecture, leading to a significant decrease in REM sleep; thus, the use of alcohol as a sleep aid remains a public health concern.


Subject(s)
Sleep, REM , Sleep , Adult , Humans , Polysomnography , Ethanol/adverse effects , Alcohol Drinking/adverse effects
3.
Sleep Health ; 10(2): 221-228, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38262777

ABSTRACT

OBJECTIVES: To test whether adolescents' mental health during the COVID-19 pandemic is associated with the combination of their instructional approach(es) and their sleep patterns. DESIGN: Cross-sectional. SETTING: Adolescents were recruited through social media outlets in October and November 2020 to complete an online survey. PARTICIPANTS: Participants were 4442 geographically and racially diverse, community-dwelling students (grades 6-12, 51% female, 36% non-White, 87% high schoolers). MEASUREMENTS: Participants completed items from the PROMIS Pediatric Depressive Symptoms and Anxiety scales. Participants reported their instructional approach(es), bedtimes, and wake times for each day in the past week. Participants were categorized into five combined instructional approach groups. Average sleep opportunity was calculated as the average time between bedtime and waketime. Social jetlag was calculated as the difference between the average sleep midpoint preceding non-scheduled and scheduled days. RESULTS: Emotional distress was elevated in this sample, with a large proportion of adolescents reporting moderate-severe (T-score ≥ 65) levels of depressive symptoms (49%) and anxiety (28%). There were significant differences between instructional approach groups, such that adolescents attending all schooldays in-person reported the lowest depressive symptom and anxiety T-scores (P < .001, ηp2 = .012), but also the shortest sleep opportunity (P < .001, ηp2 = .077) and greatest social jetlag (P < .001, ηp2 = .037) of all groups. Adolescents attending school in person, with sufficient sleep opportunity (≥8-9 hours/night) and limited social jetlag (<2 hours) had significantly lower depressive (ηp2 = .014) and anxiety (ηp2 = .008) T-scores than other adolescents. CONCLUSIONS: Prioritizing in-person education and promoting healthy sleep patterns (more sleep opportunity, more consistent sleep schedules) may help bolster adolescent mental health.


Subject(s)
COVID-19 , Depression , Mental Health , Sleep , Humans , Adolescent , COVID-19/epidemiology , Female , Male , Cross-Sectional Studies , Depression/epidemiology , Anxiety/epidemiology , Students/psychology , Students/statistics & numerical data , Surveys and Questionnaires , Child , Pandemics
4.
Article in English | MEDLINE | ID: mdl-36515855

ABSTRACT

Sleep problems are common in individuals with autism spectrum disorder (ASD). How sleep problems reflect specific ASD phenotypes is unclear. We studied whether sleep problems indexed functional impairment in a heterogeneous community sample of individuals with ASD. We analyzed 977 probands (233 females; age = 11.27 ± 4.13 years) from the Rhode Island Consortium for Autism Research and Treatment dataset, a unique public-private-academic collaboration involving all major points of service for families in Rhode Island. We found that individuals with a confirmed diagnosis of ASD were more likely to have sleep problems. However, across the whole sample and above and beyond a formal diagnosis, sleep problems were dimensionally associated with worse social impairment and poorer adaptive functioning. By using a large dataset reflective of the diversity of presentations in the community, this study underscores the importance of considering sleep problems in clinical practice to improve adaptive functioning in individuals with ASD.

5.
Sleep Health ; 8(1): 11-22, 2022 02.
Article in English | MEDLINE | ID: mdl-34991996

ABSTRACT

In fall 2019, California passed and signed into law SB328, the first US statewide legislation explicitly designed to protect adolescent sleep health by requiring most California public school districts to start no earlier than 8:00 AM for middle schools and 8:30 AM for high schools. Recognizing the unique opportunity presented by the bill's 3-year implementation period, a group of experts in adolescent sleep and school start times held a virtual summit on January 22-23, 2021 to (1) summarize the research on adolescent sleep and school start time change; (2) develop recommendations for relevant, refined, and innovative research areas and research questions; (3) provide input regarding research design, methodology, and implementation; and (4) offer a forum for networking, exchanging ideas, and establishing interdisciplinary research collaborations. Participants represented a multidisciplinary range of academic backgrounds including sleep and circadian biology, neuroscience, education, medicine, public health, mental health, safety, public policy, economics, implementation science, criminology, diversity studies, and science communication. This paper summarizes summit presentations regarding current knowledge on adolescent sleep health and school start times and key research recommendations from small group workshops on topics including research design and tools, methodological issues, sleep health disparities, logistical challenges in conducting school-based research, public-health impact, and novel and expanded approaches to research.


Subject(s)
Schools , Students , Adolescent , California , Humans , Sleep , Students/psychology , Time Factors
6.
Sleep ; 44(12)2021 12 10.
Article in English | MEDLINE | ID: mdl-34401922

ABSTRACT

STUDY OBJECTIVES: To examine associations among instructional approaches, school start times, and sleep during the COVID-19 pandemic in a large, nationwide sample of U.S. adolescents. METHODS: Cross-sectional, anonymous self-report survey study of a community-dwelling sample of adolescents (grades 6-12), recruited through social media outlets in October/November 2020. Participants reported on instructional approach (in-person, online/synchronous, online/asynchronous) for each weekday (past week), school start times (in-person or online/synchronous days), and bedtimes (BT) and wake times (WT) for each identified school type and weekends/no school days. Sleep opportunity was calculated as BT-to-WT interval. Night-to-night sleep variability was calculated with mean square successive differences. RESULTS: Respondents included 5,245 racially and geographically diverse students (~50% female). BT and WT were earliest for in-person instruction; followed by online/synchronous days. Sleep opportunity was longer on individual nights students did not have scheduled instruction (>1.5 h longer for online/asynchronous than in-person). More students obtained sufficient sleep with later school start times. However, even with the same start times, more students with online/synchronous instruction obtained sufficient sleep than in-person instruction. Significantly greater night-to-night variability in sleep-wake patterns was observed for students with in-person hybrid schedules versus students with online/synchronous + asynchronous schedules. CONCLUSIONS: These findings provide important insights regarding the association between instructional approach and school start times on the timing, amount, and variability of sleep in U.S. adolescents. Given the public health consequences of short and variable sleep in adolescents, results may be useful for education and health policy decision-making for post-pandemic secondary schools.


Subject(s)
COVID-19 , Adolescent , Cross-Sectional Studies , Female , Humans , Male , Pandemics , SARS-CoV-2 , Schools , Sleep
7.
Sleep ; 44(11)2021 11 12.
Article in English | MEDLINE | ID: mdl-34214173

ABSTRACT

STUDY OBJECTIVES: Considerable evidence shows that individuals from marginalized racial/ethnic groups in the United States experience greater rates of sleep disturbance and cardiovascular complications. Because sleep is a modifiable factor that is critically involved in cardiovascular health, improved understanding of the association between sleep and cardiovascular health during early adulthood can prevent cardiovascular disparities. This study examined racial/ethnic differences in cardiovascular function during sleep using heart rate and heart-rate-variability analyses. METHODS: Participants in this laboratory-based sleep study included healthy, "good sleepers" who were in early adulthood and resided in the United States at the time of participation (14 non-Hispanic Black [NHB; age = 30.9 (6.6), 57% female], 12 Asian [Asian, age = 26.0 (5.2), 42% female], and 24 non-Hispanic white [NHW; age = 24.6 (5.8), 79% female]). RESULTS: After adjusting for demographic factors and an apnea-hypopnea index, we found significantly higher heart rate within NREM Stage 2 (N2) (b = -22.6, p = .04) and REM sleep (b = -25.8, p =.048) and lower heart rate variability during N2 sleep (b = -22.6, p = .04) among NHB individuals compared with NHW individuals. Furthermore, NHB and Asian participants demonstrated significantly lower percent of time in slow wave sleep (SWS) compared with NHW participants (NHB: b = -22.6, p =.04; Asian: b = -22.6, p = .04). Individuals' percent of time in SWS significantly mediated differences in heart rate during N2 (indirect = 0.94, 95% CI [0.03, 2.68]) and REM sleep (indirect = 1.02, 95% CI [0.04, 3.04]). CONCLUSIONS: Our results showed disparities in sleep-related cardiovascular function in early adulthood that are mediated by SWS. These data suggest targeting sleep health in early adulthood might help reduce cardiovascular disease burden on individuals from marginalized groups.


Subject(s)
Black or African American , White People , Adult , Ethnicity , Female , Health Status Disparities , Humans , Male , Racial Groups , Sleep , United States/epidemiology , Young Adult
8.
J Child Psychol Psychiatry ; 61(10): 1061-1069, 2020 10.
Article in English | MEDLINE | ID: mdl-32361995

ABSTRACT

BACKGROUND: DNA methylation (DNAm) has been implicated in the biology of sleep. Yet, how DNAm patterns across the genome relate to different sleep outcomes, and whether these associations overlap with mental health is currently unknown. Here, we investigated associations of DNAm with sleep and mental health in a pediatric population. METHODS: This cross-sectional study included 465 10-year-old children (51.3% female) from the Generation R Study. Genome-wide DNAm levels were measured using the Illumina 450K array (peripheral blood). Sleep problems were assessed from self-report and mental health outcomes from maternal questionnaires. Wrist actigraphy was used in 188 11-year-old children to calculate sleep duration and midpoint sleep. Weighted gene co-expression network analysis was used to identify highly comethylated DNAm 'modules', which were tested for associations with sleep and mental health outcomes. RESULTS: We identified 64 DNAm modules, one of which associated with sleep duration after covariate and multiple testing adjustment. This module included CpG sites spanning 9 genes on chromosome 17, including MAPT - a key regulator of Tau proteins in the brain involved in neuronal function - as well as genes previously implicated in sleep duration. Follow-up analyses suggested that DNAm variation in this region is under considerable genetic control and shows strong blood-brain concordance. DNAm modules associated with sleep did not overlap with those associated with mental health. CONCLUSIONS: We identified one DNAm region associated with sleep duration, including genes previously reported by recent GWAS studies. Further research is warranted to examine the functional role of this region and its longitudinal association with sleep.


Subject(s)
DNA Methylation , Epigenesis, Genetic , Genome, Human/genetics , Mental Disorders/genetics , Mental Health , Sleep/genetics , Child , Cross-Sectional Studies , Female , Humans , Male
10.
Curr Biol ; 30(5): R234-R236, 2020 03 09.
Article in English | MEDLINE | ID: mdl-32155430

ABSTRACT

Patients with hippocampus lesions suffer profound failures in episodic memory. Sleep plays a key role in processing hippocampus-dependent memories. Lesioning this structure may fundamentally alter the architecture of human sleep, posing fundamental questions about the link between sleep and memory processing.


Subject(s)
Memory, Episodic , Sleep, Slow-Wave , Hippocampus , Humans , Sleep
11.
J Adolesc Health ; 66(5): 597-602, 2020 05.
Article in English | MEDLINE | ID: mdl-31974011

ABSTRACT

PURPOSE: This project investigated internal consistency and test-retest reliability of the frequently used Pubertal Development Scale (PDS) and compared parent and child reports with clinician-rated Tanner staging. METHODS: Using a repository of data collected from 1995 to 2016, 252 participants (aged 7.8-17.7 years) provided self- and parent-reported PDS and received Tanner staging by a certified health care professional within 30 days. Internal consistency and test-retest reliability statistics were evaluated for 56 children across two assessments occurring within 6 months. Comparisons with Tanner staging involved examining concurrent validity and calibration analysis using data from 233 child and 252 parental ratings. RESULTS: Self- and parent-reported PDS demonstrated good internal consistency, with Cronbach's alpha .91-.96; high test-retest reliability was confirmed with intraclass correlation coefficient .81-.92. The association of Tanner stage with self- and parent-reported PDS was moderate to high; Kendall's Tau ranged from .67 to .76, and intraclass correlation coefficient ranged from .73 to 83. The absolute agreement of Tanner stage with self- and parent-reported PDS was low; Cohen's Kappa ranged from .20 to .37. However, combining pubertal scores into three stages of development (pre/early-, mid-, and late/post-pubertal) improved interrater agreement across measures (κ = .65, 95% confidence interval = .57-.73). CONCLUSIONS: The present study shows that the PDS is reliable and generally tracks with Tanner staging (for both self and parent report). Low absolute agreement indicates that PDS categories do not map directly to specific Tanner stages, partly because a premature adrenarche is often misinterpreted by parents and pediatricians alike. However, three broad categories showed better agreement and are generally adequate for most applications in child and adolescent research.


Subject(s)
Family , Puberty , Adolescent , Child , Humans , Reproducibility of Results , Surveys and Questionnaires
12.
Appetite ; 146: 104521, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31751632

ABSTRACT

Although poor sleep has been found to adversely impact eating and weight regulation in youth, past research is limited by retrospective reporting and/or non-naturalistic designs. We investigated the feasibility of combining three momentary, ecologically valid approaches to assessing sleep and eating behavior, and associations between these constructs, among youth (aged 8-14y) with overweight/obesity (n = 40). Participants completed 14 overlapping days of actigraphy assessment and smartphone-based ecological momentary assessment (EMA) of eating behavior, of which 3 days also included computerized, self-guided 24-h dietary recall. Feasibility of completing measures concurrently was evaluated by generating frequencies of compliance. Associations between sleep indices and next-day eating behavior were examined via generalized estimating equations. Of 29 participants who provided EMA and 24-h recall data that aligned with previous night actigraphy data, both EMA and sleep data were available on an average of 8.6 out of 14 possible days, and both 24-h recall and sleep data on an average of 2.7 out of 3 possible days. Each additional hour of sleep was associated with consuming fewer calories from solid fats, alcohol, and added sugars (b = 0.70; p = .04). Combining naturalistic, momentary assessments of sleep and eating behavior appears to be acceptable in youth. Larger experimental studies are needed to further understand associations between sleep parameters and eating behavior.


Subject(s)
Ecological Momentary Assessment/statistics & numerical data , Feeding Behavior/physiology , Pediatric Obesity/physiopathology , Sleep/physiology , Time Factors , Actigraphy , Adolescent , Body Mass Index , Child , Diet/statistics & numerical data , Diet Surveys , Energy Intake , Feasibility Studies , Female , Humans , Male , Pilot Projects , Research Design
13.
J Affect Disord ; 246: 716-726, 2019 03 01.
Article in English | MEDLINE | ID: mdl-30616161

ABSTRACT

BACKGROUND: A precision medicine approach to bipolar disorder (BD) requires greater knowledge of neural mechanisms, especially within the BD phenotype. The present study evaluated differences in resting state functional connectivity (RSFC) between young adults followed longitudinally since childhood with full-threshold type I BD (BD-I)-characterized by distinct manic episodes-or a more sub-syndromal presentation of BD (BD Not Otherwise Specified [BD-NOS]), compared to one another and to healthy controls (HC). Independent Components Analysis (ICA), a multivariate data-driven method, and dual regression were used to explore whether connectivity within resting state networks (RSNs) differentiated the groups, especially for characteristic fronto-limbic alterations in BD. METHODS: Young adults (ages 18-30) with BD-I (n = 28), BD-NOS (n = 14), and HCs (n = 52) underwent structural and RSFC neuroimaging. ICA derived 30 components from RSFC data; a subset of these components, representing well-characterized RSNs, was used for between-group analyses. RESULTS: Participants with BD-I had significantly greater connectivity strength between the executive control network and right caudate vs. HCs. Participants with BD-NOS had significantly greater connectivity strength between the sensorimotor network and left precentral gyrus vs. HCs, which was significantly related to psychiatric symptoms. LIMITATIONS: Limitations included small BD-NOS sample size and variation in BD mood state and medication status. CONCLUSIONS: Results for BD-I participants support prior findings of fronto-limbic alterations characterizing BD. Alterations in the sensorimotor network for adults with BD-NOS aligns with the small but growing body of evidence that sensorimotor network alterations may represent a marker for vulnerability to BD. Further study is required to evaluate specificity.


Subject(s)
Bipolar Disorder/physiopathology , Caudate Nucleus/physiopathology , Functional Neuroimaging/methods , Magnetic Resonance Imaging/methods , Rest/physiology , Adolescent , Adult , Bipolar Disorder/diagnostic imaging , Case-Control Studies , Caudate Nucleus/diagnostic imaging , Child , Executive Function/physiology , Female , Frontal Lobe/physiopathology , Humans , Longitudinal Studies , Male , Principal Component Analysis , Young Adult
14.
Sleep ; 42(3)2019 03 01.
Article in English | MEDLINE | ID: mdl-30541103

ABSTRACT

STUDY OBJECTIVES: Sleep disruption is common in attention deficit hyperactivity disorder (ADHD). Likewise, deficits in attention are a hallmark of sleep deprivation in healthy individuals. Whether ADHD and sleep deprivation modulate common, or disparate, neural systems is unknown. No study has yet utilized functional magnetic resonance imaging (fMRI) to investigate sleep loss in ADHD. We address this gap by performing a novel meta-analysis to compare patterns of fMRI activation during sleep deprivation and ADHD. METHODS: We performed a coordinate-based activation likelihood estimate (ALE) meta-analysis using the GingerALE software. A systematic review of task-based fMRI studies of sleep deprivation vs. rested and also ADHD vs. healthy controls (HC) yielded 134 articles. fMRI coordinates were extracted for each contrast (i.e. "ADHD vs. HC," "TSD vs. Rested") and normalized to the Talairach-atlas. Separate ALE analyses were performed for ADHD and sleep deprivation. We directly compared these initial estimates to determine shared vs. distinct areas of fMRI neural activation in ADHD and sleep deprivation. RESULTS: Conjunction analyses revealed overlapping hypoactivations between ADHD and sleep loss in executive function regions, notably the dorsal anterior cingulate cortex. Sleep deprivation, however, was associated with significantly exaggerated hyperactivation in the thalamus. CONCLUSIONS: Our study indicates that ADHD and sleep deprivation share a common neural signature: hypoactivation of executive function neuroanatomy. In contrast, sleep loss, but not ADHD, was associated with thalamic hyperactivations, intimating a potential compensatory response in sleep loss not present in ADHD. By elucidating shared and distinct patterns of functional neuroanatomy, these data provide novel targets for future experimental investigations of sleep loss in ADHD.


Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnostic imaging , Brain Mapping/methods , Brain/diagnostic imaging , Magnetic Resonance Imaging/methods , Sleep Deprivation/diagnostic imaging , Attention/physiology , Attention Deficit Disorder with Hyperactivity/physiopathology , Brain/physiopathology , Executive Function/physiology , Humans , Rest/physiology , Sleep Deprivation/physiopathology
15.
J Cogn Neurosci ; 30(4): 565-578, 2018 04.
Article in English | MEDLINE | ID: mdl-29244642

ABSTRACT

Insufficient sleep is a known trigger of anxiety. Nevertheless, not everyone experiences these effects to the same extent. One determining factor is sex, wherein women experience a greater anxiogenic impact in response to sleep loss than men. However, the underlying brain mechanism(s) governing this sleep-loss-induced anxiety increase, including the markedly different reaction in women and men, is unclear. Here, we tested the hypothesis that structural brain morphology in a discrete network of emotion-relevant regions represents one such explanatory factor. Healthy participants were assessed across sleep-rested and sleep-deprived conditions, with brain structure quantified using gray matter volume measures. Sleep loss triggered greater levels of anxiety in women compared with men. Reduced gray matter volume in the anterior insula and lateral orbitofrontal cortex predicted the anxiogenic impact of sleep loss in women, yet predicted resilience in men, and did so with high discrimination accuracy. In contrast, gray matter volume in ventromedial prefrontal cortex predicted the anxiogenic impact of sleep loss in both men and women. Structural human brain morphology therefore appears to represent one mechanistic pathway (and possible biomarker) determining anxiety vulnerability to sleep loss-a discovery that may help explain the higher prevalence of sleep disruption and anxiety in women.


Subject(s)
Anxiety/diagnostic imaging , Anxiety/physiopathology , Brain/diagnostic imaging , Sex Characteristics , Sleep Deprivation/diagnostic imaging , Sleep Deprivation/physiopathology , Adolescent , Adult , Anxiety/etiology , Anxiety/pathology , Brain/pathology , Cross-Over Studies , Female , Gray Matter/diagnostic imaging , Gray Matter/pathology , Humans , Magnetic Resonance Imaging , Male , Organ Size , Resilience, Psychological , Sleep Deprivation/pathology , Sleep Deprivation/psychology , Young Adult
16.
J Neurosci ; 37(48): 11675-11687, 2017 11 29.
Article in English | MEDLINE | ID: mdl-29084867

ABSTRACT

Sleep spindles promote the consolidation of motor skill memory in young adults. Older adults, however, exhibit impoverished sleep-dependent motor memory consolidation. The underlying pathophysiological mechanism(s) explaining why motor memory consolidation in older adults fails to benefit from sleep remains unclear. Here, we demonstrate that male and female older adults show impoverished overnight motor skill memory consolidation relative to young adults, with the extent of impairment being associated with the degree of reduced frontal fast sleep spindle density. The magnitude of the loss of frontal fast sleep spindles in older adults was predicted by the degree of reduced white matter integrity throughout multiple white matter tracts known to connect subcortical and cortical brain regions. We further demonstrate that the structural integrity of selective white matter fiber tracts, specifically within right posterior corona radiata, right tapetum, and bilateral corpus callosum, statistically moderates whether sleep spindles promoted overnight consolidation of motor skill memory. Therefore, white matter integrity within tracts known to connect cortical sensorimotor control regions dictates the functional influence of sleep spindles on motor skill memory consolidation in the elderly. The deterioration of white matter fiber tracts associated with human brain aging thus appears to be one pathophysiological mechanism influencing subcortical-cortical propagation of sleep spindles and their related memory benefits.SIGNIFICANCE STATEMENT Numerous studies have shown that sleep spindle expression is reduced and sleep-dependent motor memory is impaired in older adults. However, the mechanisms underlying these alterations have remained unknown. The present study reveals that age-related degeneration of white matter within select fiber tracts is associated with reduced sleep spindles in older adults. We further demonstrate that, within these same fiber tracts, the degree of degeneration determines whether sleep spindles can promote motor memory consolidation. Therefore, white matter integrity in the human brain, more than age per se, determines the magnitude of decline in sleep spindles in later life and, with it, the success (or lack thereof) of sleep-dependent motor memory consolidation in older adults.


Subject(s)
Aging/physiology , Brain/physiology , Memory Consolidation/physiology , Motor Skills/physiology , Sleep Stages/physiology , White Matter/physiology , Adolescent , Aged , Aged, 80 and over , Brain/diagnostic imaging , Female , Humans , Male , Polysomnography/methods , White Matter/diagnostic imaging , Young Adult
17.
Sleep ; 40(9)2017 09 01.
Article in English | MEDLINE | ID: mdl-28934525

ABSTRACT

Study Objectives: Napping is a useful countermeasure to the negative effects of acute sleep loss on alertness. The efficacy of naps to recover from chronic sleep loss is less well understood. Methods: Following 2 baseline nights (10 hours' time-in-bed), participants were restricted to 7 nights of 5-hour sleep opportunity. Ten adults participated in the No-Nap condition, and a further 9 were assigned to a Nap condition with a daily 45-minute nap opportunity at 1300 h. Sleepiness was assessed using the multiple sleep latency test and a visual analogue scale at 2-hour intervals. Both objective and subjective indexes of sleepiness were normalized within subject as a difference from those at baseline prior to sleep restriction. Mixed-effects models examined how the daytime nap opportunity altered sleepiness across the day and across the protocol. Results: Short daytime naps attenuated sleepiness due to chronic sleep restriction for up to 6-8 hours after the nap. Benefits of the nap did not extend late into evening. Subjective sleepiness demonstrated a similar short-lived benefit that emerged later in the day when objective sleepiness already returned to pre-nap levels. Neither measure showed a benefit of the nap the following morning after the subsequent restriction night. Conclusions: These data indicate a short daytime nap may attenuate sleepiness in chronic sleep restriction, yet subjective and objective benefits emerge at different time scales. Because neither measure showed a benefit the next day, the current study underscores the need for careful consideration before naps are used as routine countermeasures to chronic sleep loss.


Subject(s)
Sleep Deprivation/physiopathology , Sleep Deprivation/rehabilitation , Sleep Stages/physiology , Sleep/physiology , Adolescent , Attention/physiology , Female , Humans , Male , Polysomnography , Self Report , Time Factors , Young Adult
18.
Nat Rev Neurosci ; 18(7): 404-418, 2017 07.
Article in English | MEDLINE | ID: mdl-28515433

ABSTRACT

How does a lack of sleep affect our brains? In contrast to the benefits of sleep, frameworks exploring the impact of sleep loss are relatively lacking. Importantly, the effects of sleep deprivation (SD) do not simply reflect the absence of sleep and the benefits attributed to it; rather, they reflect the consequences of several additional factors, including extended wakefulness. With a focus on neuroimaging studies, we review the consequences of SD on attention and working memory, positive and negative emotion, and hippocampal learning. We explore how this evidence informs our mechanistic understanding of the known changes in cognition and emotion associated with SD, and the insights it provides regarding clinical conditions associated with sleep disruption.


Subject(s)
Brain/physiopathology , Cognition/physiology , Emotions/physiology , Sleep Deprivation/physiopathology , Attention/physiology , Hippocampus/physiology , Humans , Memory, Short-Term/physiology , Neuroimaging , Reward , Wakefulness/physiology
19.
J Clin Child Adolesc Psychol ; 46(2): 188-197, 2017.
Article in English | MEDLINE | ID: mdl-27267670

ABSTRACT

Attention deficit hyperactivity disorder (ADHD) is associated with deficits in motor learning and sleep. In healthy adults, overnight improvements in motor skills are associated with sleep spindle activity in the sleep electroencephalogram (EEG). This association is poorly characterized in children, particularly in pediatric ADHD. Polysomnographic sleep was monitored in 7 children with ADHD and 14 typically developing controls. All children were trained on a validated motor sequence task (MST) in the evening with retesting the following morning. Analyses focused on MST precision (speed-accuracy trade-off). NREM Stage 2 sleep EEG power spectral analyses focused on spindle-frequency EEG activity in the sigma (12-15 Hz) band. The ADHD group demonstrated a selective decrease in power within the sigma band. Evening MST precision was lower in ADHD, yet no difference in performance was observed following sleep. Moreover, ADHD status moderated the association between slow sleep spindle activity (12-13.5 Hz) and overnight improvement; spindle-frequency EEG activity was positively associated with performance improvements in children with ADHD but not in controls. These data highlight the importance of sleep in supporting next-day behavior in ADHD while indicating that differences in sleep neurophysiology may contribute to deficits in this population.


Subject(s)
Attention Deficit Disorder with Hyperactivity/physiopathology , Attention Deficit Disorder with Hyperactivity/psychology , Learning/physiology , Motor Skills/physiology , Sleep Stages/physiology , Case-Control Studies , Child , Electroencephalography , Female , Humans , Male , Pilot Projects , Polysomnography
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