Sleep advances : a journal of the Sleep Research Society最新文献

Over time, memories lose episodic detail and become distorted, a process with serious ramifications for eyewitness identification. What are the processes contributing to such transformations over time? We investigated the roles of post-learning sleep and retrieval practice in memory accuracy and distortion, using a naturalistic story recollection task. Undergraduate students listened to a recording of the "War of the Ghosts," a Native American folktale, and were assigned to either a sleep or wake delay group, and either a retrieval practice or listen-only study condition. We found higher accuracy after sleep compared to wake in the listen-only condition, but not in the retrieval practice condition. This effect was driven by participants in the wake, retrieval practice condition showing superior memory compared to the wake, listen-only condition. A similar pattern was found for memory distortion, with both sleep and retrieval practice being associated with more inferences of nonpresented, but story-related information, compared to the wake, listen-only condition. These findings suggest both sleep and retrieval practice contribute to narrative memory stabilization and distortion.

Sleep has been demonstrated to support memory formation from early life on. The precise temporal coupling of slow oscillations (SOs) with spindles has been suggested as a mechanism facilitating this consolidation process in thalamocortical networks. Here, we investigated the development of sleep spindles and SOs and their coordinate interplay by comparing frontal, central, and parietal electroencephalogram recordings during a nap between infants aged 2-3 months (n = 31) and toddlers aged 14-17 months (n = 49). Spindles and SOs showed quite different maturational patterns between age groups, as to topography, amplitude, and density. Notably, spindle-SO co-occurrence in the infants did not exceed chance levels and was increased to significant levels only in the toddlers. In the infants, the slow SO upstate over frontocortical regions was even associated with a significant decrease in spindles, contrasting with the adult-like increase in spindles seen in toddlers. These results point to an immature processing in thalamocortical networks during sleep in early infancy, possibly diminishing the efficacy of sleep-dependent memory formation at this age.

This is a personal review of a research life focused on sleep in everyday life. It finds that irregular work hours shorten sleep duration and increase sleepiness, both subjectively and objectively (polysomnography). Also, experimental lab studies demonstrate reduced sleep duration (and sleep stages N2 and REM) when sleep is moved into the daylight hours (and the circadian upswing). Stage N3% seems not affected, and homeostatic experiments suggest that awakenings should not occur until the need for N3% or total spectral power has been satisfied. Furthermore, sleepiness is associated with increased alpha activity and slow eye movements, although the best indicator of dangerous sleepiness is subjective ratings (linked to perceptions of heavy eye lids). Everyday stress has very modest negative effects on objective sleep quality. Sleep loss as well as excessive sleep durations are linked to mortality, but with modest risk, and mainly in older individuals. Finally, objective sleep poorly reflects subjective sleep quality, and women appear to report poorer sleep than men, while objective data show better sleep quality in women. The discrepancy is considerably greater in older age groups.

After describing my serendipitous discovery of sleep research as a potential career, I note how my openness and inquisitiveness led to a broad contribution to sleep science. After a PhD in biological psychology, I completed a postdoctoral fellowship in alcoholism and drug abuse. This led to my first studies on rebound insomnia. I then describe early studies on the relation of sleep continuity/sleep time to daytime sleepiness and function. This led to studies of how basal sleep time/sleepiness interacts with the effects of sedating and alerting drugs. Several collaborations led to studies on sleep and hot flashes in perimenopausal women and on sleep and acute and chronic pain.

Charles Fisher is a pioneering historical figure in sleep laboratory research and sleep medicine who distinguished himself in nine areas: (1) he first documented nocturnal sleep-onset rapid eye movement (REM) sleep periods in narcoleptic patients; (2) he published the first case of polysomnography (PSG) documented acute REM sleep behavior disorder (RBD) that was triggered by sudden withdrawal from a monoamine oxidase inhibitor in 1978, 8 years before the formal identification of RBD; (3) he worked with Roffwarg and Dement on the early delineation of the ontogeny of the human sleep cycle; (4) he first demonstrated that benzodiazepine (diazepam) therapy was effective in controlling night terrors together with suppression of stage 4 non-rapid eye movement (NREM) sleep, and he was also an early investigator of night terrors as phenomena emerging from stage 4 NREM sleep, without dreaming, as had been traditionally assumed; (5) he collaborated with another pioneering sleep medicine physician, William C. Dement on studies focused on REM sleep deprivation and dreaming at Fisher's Mt. Sinai Hospital sleep laboratory in New York City; (6) he published the first PSG-documented case of sleep-related (psychogenic) dissociative disorder in 1976; (7) he first documented that typical nightmares ("anxiety dreams") occurred during REM sleep; (8) he conducted some of the earliest research, beginning in 1965, that documented cycles of nocturnal penile tumescence emerging in conjunction with REM sleep cycles; and (9) he conducted similar early studies of female sexual arousal during sleep that occurred predominantly in REM sleep.

Study objectives: This study evaluated the differences in obesity-related outcomes across multiple adolescent sleep health domains, including circadian misalignment (CM), circadian timing, and sleep duration.

Methods: 53 adolescents (aged 14-18; body mass index [BMI] percentile < 95%; 53.7% female) completed a cross-sectional study that included baseline assessment of height; weight; demographics; and 10 days assessment of sleep, physical activity, and dietary outcomes. Sleep duration, sleep timing, and physical activity data were collected from all participants using wrist-worn and waist-worn actigraphs. Dietary intake was measured using the Automated Self-Administered 24 Hours dietary recalls on 3 randomized days. Circadian timing was measured using dim-light melatonin onset (DLMO), and CM was calculated as the distance of time between DLMO and the average sleep onset time. Participants were categorized into groups (early vs late circadian timing, aligned vs misaligned circadian timing, and adequate sleep vs short sleep), and differences in dietary outcomes, physical activity, and BMI were analyzed using t-tests.

Results: Adolescents with later DLMO (M = 21:30 ± 1:11) had 0.63 higher BMI and 0.47% less averaged daily percent fat consumption than adolescents with early DLMO. Adolescents with CM (M = 1:42 ± 1:06) consumed 451.77 more averaged daily kcal consumption compared with those with circadian alignment. No statistically significant differences were found in any obesity-related outcome between sleep duration groups.

Conclusions: Our cross-sectional findings indicate that focusing on sleep timing and circadian alignment, beyond sleep duration, may promote better health outcomes for healthy adolescents. The findings of this study could enhance sleep education and inform clinical models for prevention efforts for pediatric obesity.

Study objectives: These studies disentangle the relationships between wanting to nap (nap desire), actually napping (nap behavior), and depressed and anxious mood. Study 1 partially replicated and extended findings connecting napping and depressed and anxious mood. Study 2 explored the distinction between nap desire and behavior using a new, larger sample and a different technique.

Methods: Study 1 used a longitudinal, multimethod approach to understand napping and mood among undergraduate students in the United States (N = 104). In Study 2, a cross-sectional survey was conducted on adults over 25 in the continental United States (N = 1406), including items from the DASS-21 and questions about nap desire and behavior.

Results: Study 1 found a significant relationship between same-day napping behavior and depressed mood (M _nap = 1.61, SE _nap = 0.08 vs. M _{no nap} = 1.44, SE _{no nap} = 0.06, p = .018) but not anxious mood (p = .766). Study 2 partially replicated those findings; Analysis of Covariance (ANCOVA) showed that napping desire had a significant effect on anxious (F(1, 1291) = 6.86, p = .009, partial η² = .005) and depressed mood (F(1, 1291) = 13.46, p < .001, partial η² = .010), accounting for age, gender, and restedness, but napping behavior did not add to that effect.

Conclusions: Wanting to nap is related to greater depressed and anxious mood, but actual napping did not add to that relationship. These results have implications for clinicians using sleep assessment as a screening tool for mental health and highlight the need for further research on napping motivation.

Study objectives: To evaluate sex-specific associations between known or suspected obstructive sleep apnea (OSA) and dementia risk over 10 years among older women and men.

Methods: This study included 18 815 women and men age 50+ years (dementia-free at baseline) who participated in the Health and Retirement Study (HRS), a nationally representative cohort of US adults. Presence of OSA was defined by self-reported diagnosis or key HRS items that correspond to elements of a validated OSA screening tool (STOP-Bang). Incident dementia cases were identified using a validated, HRS-based algorithm derived from objective cognitive assessments. Survey-weighted regression models based on pseudo-values were utilized to estimate sex- and age-specific differences in cumulative incidence of dementia by OSA status.

Results: Data from 18 815 adults were analyzed, of which 9% of women and 8% of men (weighted proportions) met criteria for incident dementia. Known/suspected OSA was more prevalent in men than in women (weighted proportions 68% vs. 31%). Unadjusted sex-stratified analyses showed that known/suspected OSA was associated with higher cumulative incidence of dementia across ages 60-84 years for women and men. By age 80, relative to adults without known/suspected OSA, the cumulative incidence of dementia was 4.7% higher (CI 2.8%, 6.7%) for women with known/suspected OSA, and 2.5% (CI 0.5%, 4.5%) for men with known/suspected OSA, respectively. Adjusted associations between age-specific OSA and cumulative incidence of dementia attenuated for both women and men but remained statistically significant.

Conclusions: OSA contributes to dementia risk in older adults, particularly women. This study illuminates the impact of a potentially modifiable yet frequently overlooked risk factor for dementia onset.

Background: Deep brain stimulation (DBS) is a standard treatment for movement disorders, epilepsy, and others, yet its influence on postprocedural sleep quality remains an under-researched topic.

Study objectives: We performed a systematic review and meta-analysis of all DBS effects on sleep.

Methods: The use of preferred reporting items for systematic reviews and meta-analyses guidelines (PRISMA) was utilized. We extracted demographic data, disease type/duration, DBS target, stimulation laterality (unilateral vs bilateral), follow-up lengths, and sleep pre/post-op measurements with polysomnography or across four standard sleep scales. The Cochrane methodology for evaluating RCTs was employed using the risk of bias assessments, data synthesis, and statistical methods, including forest plots (risk ratio; M-H random effects; 95% CI).

Results: Sixty-three studies were included in the overall analysis, representing 3022 patients. In a subgroup meta-analysis of subthalamic nucleus (STN) DBS for Parkinson's disease (PD), patients showed significant sleep improvement at three but not 12 months postoperatively with PDSS, at 12 but not 3 months with Epworth sleep scale, and at 6 months with nonmotor symptom scale. Pittsburgh sleep quality index (PSQI) showed no significant improvement in sleep at any time. Bilateral DBS showed significantly more improvement than unilateral DBS in the PSQI at 6 but not 3 months. Polysomnography showed significant sleep improvement at 1 week but not at 3 or 6 months. Most studies showed no significant sleep improvement for globus pallidus internus, centromedian thalamus, and ventral intermediate nucleus DBS.

Conclusions: STN-DBS for PD likely improves sleep; however, significant standardization in sleep scale outcome reporting and follow-up time is needed to effectively determine the target-dependent effects of DBS surgery on sleep.