Exercise and Sleep Loss: Effects on Recovery Sleep

The effects of exercise and sleep loss on recovery sleep were studied in young male naval volunteers. For 1 hr out of every 4 hrs during a 40-hr period, 20 subjects rested in bed and 10 subjects bicycled. Eleven measures of recovery night sleep were selected for comparison of the bedrest and exercise groups. Only one reached significance under the conservative Dunn-Bonferroni criterion: the exercise group had a higher percent total sleep time. The results indicate that exercise does increase the effects of sleep loss on recovery sleep, but that there is no simple, direct effect on specific sleep stages.     

Sleep Stage Deprivation and Total Sleep Loss: Effects On Sleep Behavior

The combined effects of total sleep loss and the deprivation of stage 4 or stage REM were studied in I two separate experiments. Two full nights or sleep loss preceded stage 4 deprivation or stage REM deprivation in Experiment 1 (N=12); 1 full night of sleep loss followed 3 nights or stage 4 deprivation or stage REM deprivation in Experiment 2 (N=I4). Total sleep loss before sleep stage deprivation significantly increased the number of attempts to enter stage 4, but had little influence on stage REM. A significant REM rebound was found in only one of the REM-deprived groups, but there was a significant stage 4 rebound in all groups on the first full recovery night, supporting the hypothesis from other studies that stage 4 has priority over REM in terms of recovery from sleep loss. The results suggested that stages 2, 3, and 4 partially overlap in their recuperative functions.     

Effect of Self-Enhanced EEG Alpha on Performance and Mood After Two Nights of Sleep Loss

Can the deleterious effects of acute sleep loss on performance and mood be ameliorated by self-enhanced alpha activity? Fourteen Naval volunteers were divided equally into an experimental (alpha-contingent auditory feedback) group and a yoked control (pseudo feedback) group. All subjects received feedback plus performance and mood tests during 3 baseline days and following 2 days and 2 nights without sleep. Feedback was given for 45 min in the morning and 45 mm in the afternoon, preceding performance and mood tests. The self-enhanced alpha (experimental) subjects did produce more alpha than the yoked controls during all feedback sessions except for one pair that was discarded. Of eleven measures that were sensitive to deep loss, two performance scores and one mood score showed significantly less sleep-loss decrement for the self-enhanced alpha group (at the usual univariate. 05 level). Two recall scores and an anxiety score showed more impairment for the self-enhanced alpha group following sleep loss. The differences were not significant, however, by (he conservative Dunn-Bonferroni multivariate criterion, so our results are not conclusive. Alpha enhancement may help maintain performance that requires continuous attention, such us counting and auditory discrimination, but does not ameliorate the sleep-loss effect for anxiety, memory, and addition.     

Sleep Loss and Nap Effects on Sustained Continuous Performance

Thirty young male volunteers participated in a study of sustained continuous performance using a variety of computer-based tasks. After 6 hrs of recorded sleep, 10 subjects were assigned to perform continuously for 42 hrs without break. Three of these subjects were unable to complete the 42-hr assignment, and 8 of the 10 suffered psychological events such as hallucinations and disorientation. Ten subjects permitted six 1-hr naps over the 42 hrs performed more successfully than those allowed no sleep. Ten subjects permitted one 6-hr rest period performed best of all. Fatigue effects appeared after 6 hrs. Time-of-day (circadian) effects were at times stronger than fatigue.     

Feedback for High EEG Alpha Does Not Maintain Performance or Mood During Sleep Loss

Can performance and mood during sleep loss be maintained by self-induced high EEG alpha activity? In a previous study, most of the performance and mood measures showed sleep-loss impairment regardless of EEG alpha level, but attention and reported sleepiness were less impaired for the high-alpha group (although the differences were of doubtful significance). A constructive replication was carried out. In Group A (N=10) auditory feedback was contingent on high alpha, and in Group B (N=10) auditory feedback was contingent on low alpha and low theta. All subjects were repeatedly measured on auditory vigilance, addition, immediate recall, and feelings of sleepiness for 40 hrs during which no sleep was permitted. Sixty min of EEG feedback were given during each block of 220 min. Group A did produce significantly more alpha for the first 24 hrs but this difference was not maintained. Both groups had significant sleep-loss impairment on all measures. There were no significant differences between the groups in the amount of impairment. Self-enhanced EEG alpha activity does not prevent impairment of performance or mood during sleep loss.     

Body Movements During Sleep After Sleep Loss

Following 4 baseline nights, 7 Ss were deprived of REM sleep for 3 nights and 7 were deprived of stage 4 sleep. Both groups were then deprived of total sleep for 1 night and then allowed 2 nights of uninterrupted recovery sleep. Compared to baseline nights, on the first recovery night the number of body movements was significantly reduced in all sleep stages and for total sleep. On the second recovery night, the number of movements was back to baseline level. The increased amount of slow-wave sleep (stages 3 and 4) during recovery sleep was not the primary reason for the reduced body motility.     

睡眠呼吸暂停监测方法及仪器的研究

介绍了睡眠呼吸暂停监测的基本原理和重要意义,阐述了国内外该领域研究的现状,分析了睡眠呼吸暂停监测的几种方法。在此基础上,研制出了价格低廉的便携式睡眠呼吸暂停监测仪。实验结果表明该仪器使用方便,精度高,性能可靠。     

The Recuperative Effects of REM Sleep and Stage 4 Sleep on Human Performance After Complete Sleep Loss: Experiment 1

Twelve young (17–21 yrs) male Navy recruits volunteered for a sleep loss study. After 4 baseline days, the Ss were completely deprived of sleep for 2 days and nights. Next followed an experimental phase of 2 days and nights after which all Ss received 2 nights of uninterrupted sleep. During the experimental phase, the 4 Ss in the REM-deprived group were aroused whenever they showed signs of REM sleep. The 4 Ss of the stage 4-deprived group were aroused whenever they showed signs of entering stage 4 sleep, and the 4 Ss of the Control group had uninterrupted sleep. All tests (speed and accuracy of addition, speed and accuracy of self-paced vigilance, errors of omission in experimenter paced vigilance, immediate recall of word lists, and mood) showed significant impairment after the first night of complete sleep loss. But during the experimental (sleep-stage-deprivation) and recovery phases, all three groups showed equal rates of recovery. Depriving the S of stage REM or stage 4 during recovery sleep does not affect the recuperation rate. Frequent arousals (50–100 per night) also do not impair recovery. The amount of sleep is probably more important than the kind of sleep.     

Spontaneous Electrodermal Activity During Sleep and Waking in Cats

This study examined the relationship between spontaneous skin potential responses (SSPRs) and the stages of sleep and waking in freely moving cats. Five adult cats were observed during 6 sleeping sessions of several hours each, permitting the analysis of several cycles of sleep in each session. Results showed a significant decrease in SSPR frequency through the different stages of vigilance, from waking, through drowsiness and slow wave sleep, to paradoxical sleep. During this last stage, spontaneous electrodermal activity was strongly reduced and few SSPRs appeared in bursts on a background of electrodermal silence. These results are discussed in relation to the known variations in spontaneous electrodermal activity in humans during sleep and in relation to the variations in some other physiological parameters during sleep.     

The Sleep of Skydivers: A Study of Stress

In this paper we report the results of a study in which we were able to assess the effects of a demonstrably stressful event—a sport parachute jump—on EEG recorded sleep. The sleep of 9 novice (one previous jump) and of 9 experienced (41 or more previous jumps) sport parachutists was monitored throughout the night for 4 nights prior to and for 1 night following the day during which a parachute jump had been scheduled to occur. A control group of sport parachutists who agreed not to make a jump during the course of their participation in the study were similarly seen for 5 consecutive nights. The results indicate that the execution, and to a lesser extent the anticipation, of the jump was stressful, especially for the novice group. However, the stressor induced only negligible changes in the sleep variables assessed. It is possible that there are critical differences in the effects on sleep of voluntarily imposed stresses and those which are commonly experienced in everyday life.     

铁路在职职工睡眠行为的现况调查

目的探讨铁路在职职工睡眠行为的特点。方法采用分层整群随机抽样的方法,抽取302名济南铁路分局在职职工。对所抽样本进行睡眠行为与睡眠质量评定量表（SBQS）及一般项目调查表的调查。全部资料用SAS软件包进行统计分析。结果铁路在职职工一般晚10时半左右上床,入睡时间需要24分钟左右,早上6时40分左右起床,每晚睡眠7小时零10分钟左右。有超过1/3的男性和超过1/2的女性有午睡的习惯,而超过40%的男性和超过30%的女性午睡的原因是因为上夜班。结论铁路在职职工的睡眠行为具有自身的特点,铁路主管部门需要针对这些特点采取应对措施,合理安排作息时间,以提高睡眠质量。     

Effects of Sleep Deprivation on Memory and Sleep Latencies in Connection with Repeated Awakenings From Sleep

Twelve subjects were kept awake 64 hrs. During baseline and recovery sleep, subjects were given a simple memory task. The subjects were awakened 3 times each night during slow-wave sleep and shown 4 playing cards. Approximately 90 min later the subjects were again awakened and tested for retention of the previous cards and given 4 new cards to learn. This procedure was repeated 3 times each night and upon awakening the following morning. On the recovery night recall was reduced, slow-wave sleep was lengthened, sleep latency was shortened, and body motility was reduced. It was suggested that the reason for the poorer recall was deeper sleep induced by the sleep deprivation.     

Sleep During and After Gradual Sleep Reduction

To determine: 1) the minimum amounts of sleep subjects would tolerate, 2) the changes in EEG sleep measures, and 3) whether subjects would revert to baseline sleep after study termination, 4 couples gradually reduced their sleep. Three couples reduced their TST in 30-min steps from a baseline of 8 hrs and one couple from a baseline of 6.5 hrs. Subjective estimates of sleep time, sleep quality, and mood were collected daily. Home EEG sleep recordings were obtained 3 nights a week. Two of the 8-hr sleepers reduced their sleep to 5.5 hrs, 2 to 5.0 hrs, and 2 reached 4.5 hrs. These 6 subjects continued sleeping 1 to 2.5 hrs below baseline amounts a year after reduction terminated. The 6.5-hr baseline couple reached 5.0 hrs and returned to 6.5 hrs TST during follow-up. Stages W, 2, and REM decreased significantly in absolute amounts. Percentage of stages W and 2 also decreased significantly. REM percent remained constant. Stage 3 was constant while stage 4 increased in both absolute and relative amounts. REM cycle length remained constant. Stage 4 rebound on 7-hr nights was not observed during times of greatest sleep reduction. Occurrences of stage REM within 10 min of stage 1 onset were observed in 2 subjects when their TST was below 6.5 hrs. Our results are consistent with other studies of shortened sleep, indicating that TST is the major determinant of sleep-stage characteristics.     

Sleep and the Transition to Adolescence: A Longitudinal Study

Study Objectives:

To assess the links between sleep and pubertal development using a longitudinal design.

Design:

Three consecutive annual assessments of sleep and pubertal development. Sleep was assessed using a week of home actigraphy.

Setting:

Naturalistic sleep in the home setting of school children, Tel Aviv Area, Israel.

Participants:

A sample of 94 (41 boys) typically developing healthy school-age children (age range at first assessment: 9.9–11.2 years).

Intervention:

N/A

Measurements and Results:

The Petersen''s Pubertal Development Scale (PDS) and Sexual Maturation Scale (SMS) were used to assess pubertal development, and a week of actigraphy served to assess naturalistic sleep patterns. The results reflect expected developmental trends: an increase in signs of pubertal maturation, delayed sleep onset, and shorter sleep time. After controlling for age, significant relationships were found between sleep onset time, true sleep time, and number of night wakings at Time 1 and pubertal ratings at Time 2, and pubertal changes from Time 1 to Time 2. Delayed and disrupted sleep at Time 1 predicted faster pubertal changes from Time 1 to Time 2. These results were supported by structural equation modeling. These findings were similar in boys and girls.

Conclusions:

Based on these longitudinal data, it appears that pubertal changes in sleep (delayed sleep phase and disrupted sleep patterns) antedate bodily changes associated with puberty. The underlying mechanisms explaining these predictive links should be further explored.

Citation:

Sadeh A; Dahl RE; Shahar G; Rosenblat-Stein S. Sleep and the transition to adolescence: a longitudinal study. SLEEP 2009;32(12):1602-1609.     

78例睡眠呼吸暂停综合征患者的睡眠特征及其与夜间低氧血症的关系

目的 :了解SAS患者的睡眠特征及其与夜间低氧血症的关系。方法 :采用PSG对 78例SAS患者和 30例正常对照者进行整夜睡眠监测 ,比较两组间的睡眠特征。并对不同严重程度的夜间低氧血症SAS患者进行睡眠变量比较 ,分析二者的关系。结果 :与正常对照者相比 ,SAS患者夜间睡眠结构紊乱 ,主要为深睡眠减少、浅睡眠相对增加、REM睡眠减少、觉醒增加、睡眠潜伏期缩短、呼吸暂停或低通气次数增加、动脉血氧饱和显著下降 (P <0 .0 5 )。SAS患者夜间最低血氧饱和度与夜间总睡眠时间、睡眠效率、NREM睡眠时间及呼吸紊乱指数呈显著负相关 (r>0 .3,P <0 .0 5 ) ,与觉醒比例呈显著正相关 (r >0 .5 ,P <0 .0 1)。结论 :SAS患者睡眠结构紊乱突出 ,夜间反复发作的低氧血症对睡眠质量产生较大影响。     

基于BP网络的睡眠分阶方法及睡眠质量评估研究

我们利用不同睡眠期脑电复杂性特征与睡眠深度的关系及多道睡眠图功率谱特征,基于3层BP网络进行了睡眠自动分阶的研究,并提出了能部分反映睡眠质量的睡眠时间、浅睡时间、深睡时间、REM时间、觉睡比、醒转次数等参数。通过6例全睡眠监护实验说明,该方法可为睡眠质量的评价提供途径。     

Effects of Prolonged Sleep Deprivation, With and Without Chronic Physical Exercise, on Mood and Performance

The effects of physical exercise and sleep deprivation on mood and cognitive performance were studied in 12 healthy young male volunteers deprived of sleep on two occasions. During the first 60-hr period without sleep, half of the subjects walked on a treadmill at 25–30% of their maximum aerobic capacity (Exercise condition) for 1 out of every 3 hrs while the remaining 6 subjects remained physically inactive (No Exercise condition) during that same hour. Eight weeks later the same 12 subjects underwent an identical sleep-deprivation protocol except that those who were previously inactive exercised, while those who previously exercised remained inactive. Throughout the sleep deprivation periods, subjects in both conditions completed subjective assessments of fatigue, sleepiness and mood every 3 hrs, performed an auditory vigilance task every 6 hrs, and completed a cognitive test battery every 12 hrs. The results revealed clear decrements in mood and performance as a function of sleep loss. However, with the exception of somewhat more long reaction times in the Exercise condition, exercise neither increased nor decreased the impairment induced by sleep deprivation.     

大学生睡眠质量及其相关影响因素的研究

目的:了解大学生的睡眠质量及其与人格倾向、主观幸福感、心理症状等因素的关系。方法:通过整群随机抽样选取313名大学生为调查对象,采用匹兹堡睡眠质量指数(PSQI)和相关量表评定大学生的睡眠质量及相关心理状况。结果:大学生PSQI总均分为5.14±2.71,睡眠障碍发生率18.2%;体育锻炼和睡眠习惯对大学生睡眠质量有影响;人际关系、身体状况、生活习惯、主观幸福感、人格倾向、心理症状与睡眠质量有显著相关,产生重要影响的因素主要有身体状况、心理症状和人格倾向。结论:大学生睡眠质量问题应引起重视,采取综合措施改善大学生的睡眠问题,可促进其身心健康。     

Studies of Spontaneous Electro dermal Responses in Sleep

A series of studies on spontaneous electro dermal responses (storming) in normal human stage 3–4 sleep J5 reported. It was found that: (a) storming rates during sleep are positively correlated with spontaneous response rates during wakefulness, (b) more storming is demonstrated by subjects who remain awake during a baseline recording at the start of the night, (c) there is a negative correlation between storming rate and amount of stage 3–4 sleep, (d) storming rates decrease from night 1 to night 2, (e) stunners differ from non-stormers on several MMPI measures of anxiety and ego-strength, and (f) dream reports are given more often on awakenings from storming than non-storming stage 3–4 sleep. The results are compared to other studies of storming, and the conclusion is made that storming is related to presleep variables and is not a simple byproduct of a release of cortical inhibitory mechanisms. If one function of storming is to reduce the amount of stage 3–4 sleep, this might have survival value in the presence of environmental threat.     

Sleep on the Night Shift: 24-Hour EEG Monitoring of Spontaneous Sleep/Wake Behavior

The present study sought to objectively describe the spontaneous sleep/wakefulness pattern of shift workers during a 24-hour period. Portable Medilog tape-recorders were used for ambulatory EEG monitoring of 25 male papermill workers (25-55 years) during days with night and afternoon work. The results showed that sleep after night work was two hours shorter than after afternoon work. The sleep reduction affected mainly Stage 2 and REM sleep while slow wave sleep was unchanged. In connection with night work 28% of the workers took a nap in the afternoon. These naps contained a large proportion of slow wave sleep and were, apparently, caused by the sleep deficit after the short main sleep period. The EEG recordings also revealed that 20% of the participants had sleep episodes during night work. These naps were as long as the afternoon naps, were experienced as "dozing offs" rather than naps, occurred at the time of the trough of the circadian wakefulness rhythm, and were concomitant with extreme subjective sleepiness and low rated work load. It was concluded that not only the sleep of shift workers was disturbed, but also the wakefulness--to the extent that sleepiness during night work sometimes reached a level where reasonable wakefulness could not be maintained. The latter observation is probably of special importance in work situations demanding a great responsibility for human lives or for great economic values.