Children's objective and subjective sleep disruptions: links with afternoon cortisol levels.

OBJECTIVE: The purpose of this study was to determine possible relations between the quality and amount of children's sleep and cortisol in healthy children. DESIGN: Children's sleep was monitored with actigraphs for 7 nights. Children came to the laboratory to provide saliva samples, which were used to assess cortisol. Children reported on their sleepiness and sleep/wake problems. Sixty-four healthy children participated (M = 8.75 years; SD = .55). MAIN OUTCOME MEASURES: Self-reported sleepiness and sleep/wake problems, actigraphy-measured total sleep minutes, sleep efficiency, minutes awake after sleep onset, and sleep activity, and afternoon cortisol levels. Results: After controlling for demographic variables and child characteristics, higher levels of cortisol were related to increased subjective sleep problems and objective measures of shorter sleep duration and poorer sleep quality. CONCLUSION: These findings are of importance for understanding critical facets of children's health and well-being, and are noteworthy given the high prevalence of sleep disruptions in otherwise normally developing children in the United States.     

Fibromyalgia: the role of sleep in affect and in negative event reactivity and recovery

OBJECTIVE: Fibromyalgia (FM) syndrome is a chronic pain condition characterized by diffuse muscle pain, increased negative mood, and sleep disturbance. Until recently, sleep disturbance in persons with FM has been modeled as the result of the disease process or its associated pain. The current study examined sleep disturbance (i.e., sleep duration and sleep quality) as a predictor of daily affect, stress reactivity, and stress recovery. DESIGN AND MEASURES: A hybrid of daily diary and ecological momentary assessment methodology was used to evaluate the psychosocial functioning of 89 women with FM. Participants recorded numeric ratings of pain, fatigue, and positive and negative affect 3 times throughout the day for 30 consecutive days. At the end of each day, participants completed daily diary records of positive and negative life events. In addition, participants reported on their sleep duration and sleep quality each morning. RESULTS: After accounting for the effects of positive events, negative events, and pain on daily affect scores, it was found that sleep duration and quality were prospectively related to affect and fatigue. Furthermore, the effects of inadequate sleep on negative affect were cumulative. In addition, an inadequate amount of sleep prevented affective recovery from days with a high number of negative events. CONCLUSIONS: These results lend support to the hypothesis that sleep is a component of allostatic load and has an upstream role in daily functioning.     

Borrowing from Sleep to Pay Work and Family: Expanding Time‐Based Conflict to the Broader Nonwork Domain

We extend cross‐domain research by examining sleep, a domain within the larger nonwork domain that competes for time with work and family domains. We draw from scarcity theory and research on slack resources to contend that, because people cannot increase the amount of time they have, they borrow time from sleep in order to spend more time working and with family. Utilizing a Bureau of Labor Statistics survey of 10,741 participants, we find nonlinear and interactive effects of time spent working and time spent with family on sleep time, suggesting that the negative effects of work and family on sleep time are especially strong when demands for work and family are high. In an experience sampling field study of 122 working adults, we similarly find a nonlinear effect of work time on sleep time as well as an interaction between work time and family time in predicting time spent sleeping. Both studies indicate that as slack time resources become increasingly scarce, time spent working and time spent with family have increasingly powerful negative effects on time spent sleeping. Contrary to our expectations, we found no support for gender as a moderator of these effects.     

Culture and the organization of infant sleep: A study in the Netherlands and the U.S.A.

This study investigates differences in the amount and structure of infant sleep in two cultural places with previously documented, divergent parental beliefs and practices. Eight-month-old infants (n = 24 per site) were recruited from towns in the Netherlands and the eastern U.S.A. To evaluate sleep, infants’ physical activity was recorded at home for 24 h using a miniature actigraph, while parents kept a diary of infant activities. Measures derived from actigraphy include total sleep, longest sleep episode, longest wake episode, number of sleep episodes, and percent of sleep during nighttime, as well as time in the stages of Quiet and Active Sleep. Measures based on the parental diaries include most of these aspects as well, except those related to sleep stages. Results based on the more precise actigraphy method indicate that (1) the Dutch infants averaged 13.65 h of sleep per 24 h, 1.67 h more than the U.S. infants; this difference was mostly due to daytime sleep; (2) The Dutch infants’ longest wake episode averaged less than that of the U.S. infants, while their longest sleep episode appeared slightly longer. (3) The Dutch infants, compared to the U.S. sample, spent more time in the Quiet, rather than the Active phase of sleep; (4) They began their Quiet sleep earlier in the evening than did their U.S. counterparts. Measures derived from parental diaries are largely in agreement with the actigraph findings. These results are consistent with reported and observed practices and beliefs in the two communities. The pattern of differences – less apparent maturity among the Dutch in the amount of sleep, but greater apparent maturity in the structure of sleep -- illustrates that behavioral and neurological maturity can be assessed only in the context of the developing child’s adaptation to the specific demands and affordances of the culturally structured developmental niche.     

Influence of lateral motion transfer on sleep.

This study examined the effects of motion of an artificial bed partner on the sleep of a real subject on the same mattress. A 240-lb eight-sided cylindrical roller served as the artificial bed partner. The roller was placed on one side of a king-size mattress and a normal adult slept on the other half. On experimental nights, the roller intermittently rocked back and forth for brief periods of time which in aggregate represented approximately 13% of total sleep time. On control nights, the roller was stationary. After an adaptation night in the laboratory, subjects spent two more nights in the sleep laboratory. The order of Roller On and Roller Off nights was random. 24 subjects were randomly assigned to sleep on the three surfaces. The three mattresses used in the study had different construction designs and in turn variable properties of motion transfer. Sleep variables were measured objectively by nocturnal polysomnography and subjectively by a postsleep questionnaire. Analysis of the data indicated that motion transferred laterally across a mattress was associated with a significant increase in Stage 1 sleep, and a significant decrease in Stage 3/4 sleep. Over-all, sleep efficiency, number of awakenings, and wakefulness after sleep onset did not show significant changes from control to experimental nights. The amount of change in sleep architecture, however, was more notable on the mattresses which transferred more motion. An implication of these findings is that motion transferred across the surface of a mattress, by lightening the depth of the sleep and thereby decreasing the auditory arousal threshold, can increase the potential for sleep disruption from environmental stimuli such as noise.     

糖尿病与睡眠的相互关系

人一生中有1／3的时间在睡眠中度过,睡眠质量直接关系到一个人的身体健康。睡眠时间过少或过多的人糖尿病患病率大大增加。糖尿病本身的病理、生理特点,严重影响患者的睡眠质量,睡眠质量又可以反过来影响糖尿病患者的血糖水平。有研究显示,糖尿病患者最佳睡眠时间为8小时。同时糖尿病患者中睡眠呼吸暂停综合征（OSAS）患病率高,0SA...     

Effects of flurazepam and triazolam on neuropsychological performance

A double-blind study examined the effects of a single dose of either triazolam or flurazepam on measures of concept formation, attention, concentration, and motor function, the morning following drug ingestion. Subjects were 53 healthy university students, screened for history of neurological or psychiatric illness. In comparison to placebo-treated controls, there was no difference in the effects on neuropsychological performance, although subjects who received flurazepam reported more side effects. It was concluded that although these drugs may produce side effects, single doses do not appear to impair various aspects of neuropsychological ability the morning after ingestion.     

Sleep patterns and sleep disruptions in school-age children

This study assessed the sleep patterns, sleep disruptions, and sleepiness of school-age children. Sleep patterns of 140 children (72 boys and 68 girls; 2nd-, 4th-, and 6th-grade students) were evaluated with activity monitors (actigraphs). In addition, the children and their parents completed complementary sleep questionnaires and daily reports. The findings reflected significant age differences, indicating that older children have more delayed sleep onset times and increased reported daytime sleepiness. Girls were found to spend more time in sleep and to have an increased percentage of motionless sleep. Fragmented sleep was found in 18% of the children. No age differences were found in any of the sleep quality measures. Scores on objective sleep measures were associated with subjective reports of sleepiness. Family stress, parental age, and parental education were related to the child's sleep-wake measures.     

Sleep and the time course of motor skill learning

Growing evidence suggests that sleep plays an important role in the process of procedural learning. Most recently, sleep has been implicated in the continued development of motor-skill learning following initial acquisition. However, the temporal evolution of motor learning before and after sleep, the effects of different training regimens, and the long-term development of motor learning across multiple nights of sleep remain unknown. Here, we report data for subjects trained and retested on a sequential finger-tapping task across multiple days. The findings demonstrate firstly that following initial training, small practice-dependent improvements are possible before, but not following the large practice-independent gains that develop across a night of sleep. Secondly, doubling the quantity of initial training does not alter the amount of subsequent sleep-dependent learning that develops overnight. Thirdly, the amount of sleep-dependent learning does not correlate with the amount of practice-dependent learning achieved during training, suggesting the existence of two discrete motor-learning processes. Finally, whereas the majority of sleep-dependent motor-skill learning develops during the first night of sleep following training, additional nights of sleep still offer continued improvements.     

Trends in timing of sleep in the general population of Norway: 1980 to 20001

The aim of the current study was to examine whether the timing of sleep have changed over the last two decades. As part of a general survey of activities throughout the 24-hr. cycle, collected in 1980, 1990, and 2000 by Statistics Norway, information on sleep timing was obtained for every 15-min. interval for 1 wk. All three samples were representative of Norwegians. The age span was from 16 to 74 years. Timing of sleep was significantly delayed in 2000 compared to 1990 and especially so in 1980, but with no change in total amount of sleep. From 1980 to 2000, there was an increasing discrepancy in sleep or wake timing between weekdays and weekends. The current analyses show that people sleep as much as before but do so at different times. The increased discrepancy between weekdays and weekends indicates that overall sleep habits are poorer now than previously.     

Morningness-eveningness and sleep habits among adolescents: age and gender differences

Previous research has indicated the need to use large samples in different cultural contexts in order to clarify age and gender differences on morningness-eveningness and sleep habits. The goal of our research was to study the relationship between morningness-eveningness and sleep habits in a large sample of 2,649 adolescents between 12 and 16 years. The Morningness- Eveningness Scale for Children and an adaptation of the School Sleep Habits Survey measures were used. Results indicated a greater tendency toward eveningness with age and higher eveningness in 13- and 14-year-old girls. Older adolescents claimed later rising time on weekends, later bedtime and shorter sleep length, and greater social jetlag, weekend rise time delay, and weekend bedtime delay. Girls reported earlier rising time on weekdays, later rising time on weekends, longer sleep length on weekends, and greater social jetlag and weekend rising time delay. Lastly, evening oriented adolescents claimed later rising time and bedtime, shorter sleep length on weekdays but longer sleep duration on weekends, and greater social jetlag, weekend rising time delay, and weekend bedtime delay.     

One Night of Sleep Loss Impairs Innovative Thinking and Flexible Decision Making

Recent findings with clinically oriented neuropsychological tests suggest that one night without sleep causes particular impairment to tasks requiring flexible thinking and the updating of plans in the light of new information. This relatively little investigated field of sleep deprivation research has real-world implications for decision makers having lost a night's sleep. To explore this latter perspective further, we adapted a dynamic and realistic marketing decision making “game” embodying the need for these skills, and whereby such performance could be measured. As the task relied on the comprehension of a large amount of written information, a critical reasoning test was also administered to ascertain whether any failure at the marketing game might lie with information acquisition rather than with failures in decision making. Ten healthy highly motivated and trained participants underwent two counterbalanced 36 h trials, sleep vs no sleep. The critical reasoning task was unaffected by sleep loss, whereas performance at the game significantly deteri orated after 32–36 h of sleep loss, when sleep deprivation led to more rigid thinking, increased perseverative errors, and marked difficulty in appreciating an updated situation. At this point, and despite the sleep-deprived participants' best efforts to do well, their play collapsed, unlike that of the nonsleep-deprived participants.     

Repetitive Thought Impairs Sleep Quality: An Experience Sampling Study

Although previous research has suggested that presleep negative cognitive activities are associated with poor sleep quality, there is little evidence regarding the association between negative thoughts and sleep in real-life settings. The present study used experience sampling and long-term sleep monitoring with actigraphy to investigate the relationships among negative repetitive thought, mood, and sleep problems. During a 1-week sampling period, 43 undergraduate students recorded their thought content and mood eight times a day at semirandom intervals. In addition to these subjective reports, participants wore actigraphs on their wrists in order to measure sleep parameters. Analyses using multilevel modeling showed that repetitive thought in the evening was significantly associated with longer sleep-onset latency, decreased sleep efficiency, and reduced total sleep time. Furthermore, impaired sleep quality was significantly associated with reduced positive affect the next morning, and decreased positive affect was indirectly associated with increased repetitive thought in the evening. These findings suggest the existence of a self-reinforcing cycle involving repetitive thought, mood, and impaired sleep quality, highlighting the importance of cognitive and emotional factors in enhancement and maintenance of good-quality sleep.     

The Effects of Exercise as a Countermeasure for Fatigue in Sleep-Deprived Aviators

This study examined the effectiveness of exercise for sustaining performance despite moderate amounts of sleep. Twelve volunteers engaged in 10-min bouts of exercise during one 40-hr period of sleep deprivation and rested for an equivalent amount of time during a 2nd period. Participants were more alert immediately following exercise, as evidenced by longer sleep latencies, than after the resting, control condition. However, electroencephalogram data collected 50 min following exercise or rest showed that exercise facilitated increases in slow-wave activity, signs of decreased alertness. Cognitive deficits and slowed reaction times associated with sleep loss were equivalent in both conditions. The results from this study suggest that short bouts of exercise may ameliorate some of the increases in sleepiness and fatigue associated with sleep loss for a short period of time but are not likely to prevent performance decrements. In addition, less than 1 hr following exercise, significant increases in fatigue and sleepiness may occur.     

Vicious Cycles of Sleeplessness,Sleep Phobia,and Sleep-Incompatible Behaviours in Patients with Persistent Insomnia

Abstract

In order to study the possible role of vicious cycles of sleeplessness, sleep-incompatible behaviours, and sleep phobia in patients with persistent insomnia, 70 insomniacs were compared with 70 controls on a Sleep Behaviour Questionnaire. Although the insomniacs reported much shorter sleep time than the controls, they did not differ on the amount of time spent in bed. They reported more thinking about problems and planning in bed, but did not report more overt sleep-incompatible behaviours than the controls. The notion of sleep phobia was weakly supported, but the results clearly supported the notion of vicious cycles of sleeplessness (worries, frustration, and negative expectations about sleeplessness). In a second study, SBQ items were factor analyzed, and correlations between SBQ items and personality variables, depression, and stress measures were studied. The item that correlated most strongly with degree of reported sleeping problems referred to negative expectations about sleeplessness. Factor analysis identified four factors: negative expectations, worrying, frustration over sleeplessness, and sleep phobia, with negative expectations accounting for most of the variance.     

Sleep deprivation and sustained attention performance: integrating mathematical and cognitive modeling

A long history of research has revealed many neurophysiological changes and concomitant behavioral impacts of sleep deprivation, sleep restriction, and circadian rhythms. Little research, however, has been conducted in the area of computational cognitive modeling to understand the information processing mechanisms through which neurobehavioral factors operate to produce degradations in human performance. Our approach to understanding this relationship is to link predictions of overall cognitive functioning, or alertness, from existing biomathematical models to information processing parameters in a cognitive architecture, leveraging the strengths from each to develop a more comprehensive explanation. The integration of these methodologies is used to account for changes in human performance on a sustained attention task across 88 h of total sleep deprivation. The integrated model captures changes due to time awake and circadian rhythms, and it also provides an account for underlying changes in the cognitive processes that give rise to those effects. The results show the potential for developing mechanistic accounts of how fatigue impacts cognition, and they illustrate the increased explanatory power that is possible by combining theoretical insights from multiple methodologies.     

Dual Trajectories of Sleep Duration and Cigarette Smoking during Adolescence: Relation to Subsequent Internalizing Problems

Decreasing sleep duration and increasing cigarette smoking of adolescents are major public health concerns. However, research examining connections between the developmental trajectories of the outcomes that are evolving contemporaneously and their relation to long-term outcomes is still lacking. This study examined distinct trajectories of sleep duration and cigarette smoking during adolescence, associations between these trajectories, and links with internalizing problems during young adulthood. Data were collected from 2510 adolescents who participated in a longitudinal study spanning from 2006 through 2014 in northern Taiwan. Group-based dual trajectory modeling was used to examine the dynamic relationships between sleep duration and cigarette smoking trajectories during adolescence. Multiple linear regression was used to understand the association between the distinct trajectories and subsequent internalizing problems. Three sleep duration trajectories (short decreasing, typical sleep, and long sleep) and three cigarette smoking trajectories (nonsmokers, late increasing, and escalating smokers) were identified. We found significant inter-relationships for sleep duration and cigarette smoking trajectories during adolescence; all atypical sleep duration trajectories conferred increased risks of increased cigarette smoking and vice versa. In addition, the effects of sleep duration and cigarette smoking on later internalizing problems were found to vary by sex and trajectory patterns. These results provide insight regarding the co-development of sleep duration and cigarette smoking trajectories during adolescence. We also highlight the different roles of sleep duration and cigarette smoking trajectories and their relation to internalizing problems of young adulthood.     

Twenty-four-hour sleep-wake patterns in a nursing home population

Sleep-activity patterns were objectively recorded over a 24-hr period in 19 elderly nursing home residents. On average, both sleep and wake times were observed during every hour of the 24 recorded hours; however, the sleep pattern of the residents was fragmented so that they rarely experienced even a single hour of consolidated time spent sleeping. It is hypothesized that several independent factors, including compensation for lost sleep, increased total time in bed, weakening of social constraints, and deterioration of the circadian sleep-wake rhythm, are interacting to produce this increase in sleep fragmentation.     

Performance on a simple reaction time task while sleep deprived

Divergent results have been reported on the effect of a night's sleep loss on performance of a single monotonous task. The present experiment examined the effect that partial sleep deprivation had on 10 participants' performance on a simple reaction time task requiring low responding for 120 min. compared to performance on the same task when well rested. Participants missed significantly more signals and had slower reaction times when sleep deprived. Reaction times increased with time when participants were both sleep deprived and rested, but the number of misses did not significantly change over time. Reaction time was significantly correlated with subjective ratings of sleepiness and heart rate in both conditions. EEG and heart-rate variability measures did not correlate significantly with reaction time. Misses correlated significantly with subjective ratings and heart rate but only in the rested condition.     

Sleep disturbance in intentional self-awakenings: behavior-genetic and transient factors

Unaided self-awakenings were studied, using a baseline vs treatment comparison with 84 undergraduate subjects serving as their own controls. The data suggest that situational constraints related to time and sleep environment affect successful awakenings, that the subjects' instructional set produces a temporary sleep disturbance, and that chronically sleep satisfied or dissatisfied groups respond differently to the procedures used here.