摘要:

Evidence from human free‐running studies has suggested a close relationship between the timing of the circadian rhythm of core body temperature and the rhythm of sleep propensity. However, this relationship may be questioned by variations of sleep and wakeful activity which could have masked the endogenous temperature rhythm. A constant routine was used here to «unmask» the endogenous temperature rhythm in addition to frequent sleep trials across a 24‐h period to confirm the relationship between temperature and sleep propensity rhythms. Of the 14 healthy, good sleeping subjects 13 had significant 24‐h cosine rhythms of sleep propensity. Eight of these also had a significant 12‐h cosine rhythm. The eight subjects with both 24‐h and 12‐h rhythms showed a minor peak of sleep propensity in the early afternoon followed by a trough in the early evening (20.00 hours). Sleep propensity then rose rapidly at about midnight to a major peak in the early morning. This was followed by a second trough of sleep propensity in the late morning. The average times of the sleep propensity phases relative to the circadian temperature rhythm were very similar to the earlier free‐running studies. Furthermore, the times of the sleep propensity phases were highly correlated with the body temperature minimum. These results suggested the possibility that a common oscillator determines the timing of both the body temperature rhythm and the phases of the sleep pr

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00005.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Previous research has shown that night driving performance may be seriously affected by sleepiness. The present study compared daytime and night‐time performance of professional drivers on a simulated truck driving task. A secondary purpose was whether a nap or a rest pause would affect performance. Nine professional drivers participated in a counterbalanced design. The conditions were day driving (DAYDRIVE), night driving (NIGHTDRIVE), night driving with a 30 minute rest (NIGHTREST), and night driving with a 30 minute nap (NIGHTNAP). Each condition consisted of three consecutive 30‐min periods. For the DAYDRIVE and NIGHTDRIVE all periods were spent driving while the second period was either a rest pause or a nap for the other two conditions. Mean speed, standard deviation of speed and, standard deviation for lane position were recorded. Self ratings of sleepiness were obtained before and after each 30‐min period. Reaction time tests and 10 minute standardized EEG/EOG recordings were obtained before and after each condition. EEG/EOG were also recorded continuously during driving. The effects on driving were small but significant: night driving was slower, with a higher variability of speed, and had higher variability of lane position. Subjective and EEG/EOG sleepiness were clearly higher during the night conditions. Reaction time performance was not significantly affected by conditions. Neither the nap nor the rest pause had any e

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00013.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The effects of the vertical inversion of the visual field on REM sleep mental activity were examined to explore the potential involvement of this activity in information processing. In a first experiment, four male subjects slept in the laboratory for two sessions of 6 consecutive nights: 2 adaptation nights, 2 nights of polysomnography and 2 nights of dream collection. During the days preceding Nights 3, 4, 5, 6 of each session, the subjects wore glasses which, during the second session, completely inverted (rotation of 180°) their visual field. In a second experiment with four other male subjects, the order of conditions was reversed and the experimental condition (visual inversion) was introduced twice. The data of the two experiments were combined. Overall, following visual inversion, there were significant increases in the proportion of dreams containing motor and visual difficulties (P<0.005), misfortunes (P<0.05) and dreamer confusion (P<0.05) and a decrease in dreamer participation (P<0.05). Only 4 of the 8 subjects experienced incorporations of the inverted visual field into their dreams and they tended to perform better on two of three tests of adaptation to the visual inversion. The observed changes in dreams are consistent with the notion of continuity between waking and dreaming since they appear to reflect the waking preoccupation and psychological state associated with visual inversion

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00001.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Behavioural sleep was assessed for 152 nights in 5 adult, 2 immature and 1 juvenile giraffes at a zoological garden, using continuous time‐lapse video recording. Sleep occurred while the giraffes were standing (SS) and in recumbency (RS). Paradoxical sleep (PS) was recognized by the peculiar positioning of the head on the croup and by phasic events. The 24‐h sleep profile had a main bimodal nocturnal sleep period between 20.00 and 07.00 hours, with a trough between 02.00 and 04.00 hours, and several short naps between 12.00 and 16.00 hours. Total sleep time (TST), excluding the juvenile, was 4.6 h, whereby PS comprised only 4.7%. TST was not age dependent, but the lowest amount of RS and the highest amount of SS occurred in the oldest and the two oldest animals, respectively. Sleep was fragmented, as indicated by the predominance of RS episodes lasting less than 11 min. Sleep cycle duration was very variable with most values between 1 and 35 min (when no waking or RS was allowed within PS episodes), or 6–35 min (when the criteria for ending a PS episode allowed 1–2 min interruptions by RS). There were several indications for sleep regulation: (i) RS and SS complemented each other to yield a relatively stable daily value of TST; (ii) sleep was redistributed on nights following a day when the giraffes spent a few hours in an outside enclosure. The first peak of the bimodal sleep profile was absent and RS was more prominent in the second half of the night compared with nights following days spent in the barn; and (iii) napping was followed by a minor reduction of RS and an increase in SS in the subsequent night compared with nights following days witho

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00010.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

It is well‐established that heart rate is decreased in NREM sleep relative to wakefulness, but the extent and progression of variations in heart rate when NREM sleep is first initiated, i.e. at sleep onset, have not been detailed. Furthermore, since physiological variations which have been documented during the sleep onset period have been based on studies of adult subjects, developmentally related influences on this process have not been examined. The present investigation addressed these issues by examining beat‐to‐beat (RR interval) changes in heart rate during the transitions between wakefulness, initial Stage 1, and subsequent Stage 2 sleep in normal and reading disabled male preadolescents who participated in a four‐consecutive‐night baseline sleep study. To avoid the influence of sleep deprivation or the effects of multiple sleep onset attempts, only initial, uninterrupted sleep onset periods from post‐adaptation nights were selected for study. For both groups the results indicated a significant slowing of heart rate beginning 30 s prior to Stage 1 onset, and a further decrease within 30 s of Stage 2 onset. In addition to providing new developmental data documenting heart rate variations in the wake/sleep transition, these results complement previous reports indicating motor and autonomic changes occurring in anticipation of Stage 1 onset. These data are also relevant to an ongoing controversy regarding whether initial Stage 1 or Stage 2 sleep should be considered as the time of sleep onset. To the extent that the systematic and coordinated variations across systems may be taken as an index of state change, and in the absence of remarkable differences in these variations between Stage 1 and subsequent Stage 2, the present data are most consistent with considering initial Stage 1 as the earliest EEG sign of physiological

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.d01-50.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Changes in mean arterial pressure (MAP) and heart rate (HR) during sleep were recorded at three ambient temperatures (Ta: 16, 22 and 28°C). MAP and HR during sleep increased with lowering ofTa. The increase in MAP during the transition from NREM to REM sleep was decreased by lowering theTa. At 28°C, the average HR increased in going from NREM to REM sleep, while, at 16°C, it decreased. The coefficient of variation (CV%) of the MAP during REM sleep decreased as theTawas lowered, while that seen during NREM sleep was unchanged. This study suggests thatTahas a greater effect than sleep stage on the MAP and HR, and that MAP variability during REM sleep is greater at higher

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00007.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

A review was made of the literature relating sleep apnoea to sympathetic nervous system (SNS) activity, as inferred from catecholamine levels or muscle sympathetic nerve activity (MSNA). Twenty‐four studies were located. Most studies reported an elevation of norepinephrine and MSNA, both during sleep and wakefulness among individuals with sleep apnoea. However, studies rarely controlled for known confounders of sympathetic activity, making the validity of the findings questionabl

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00006.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

A self‐report postal questionnaire was sent to 5000 (3612 male) drivers randomly selected from the policy holders of an insurance company which insures only motorists who have achieved a maximum «no‐claims bonus». The questionnaire sought demographic and physical details (sex, age, height, weight and collar size), driving history (number of years, average mileage), accident history (number, number of «near misses»), frequency of events due to sleepiness (accidents, pulling off the road, falling asleep at the wheel), frequency and severity of snoring and sleep pattern and severity of EDS. Of the 2247 (44.9%) responses received, 1609 (44.5%) were male and 638 (46%) female. Snorers were more likely to report daytime sleepiness than non‐snorers and were more likely to have had to pull off the road due to sleepiness. Despite this increased sleepiness there were no significant differences in overall accident rate. These results were obtained from a population with a maximum «no‐claims bonus» which would have excluded any subjects who had already had a recent accident due to sleepiness. Thus the results probably underestimate the problem. It is concluded that snorers tend to be sleepier than non‐snorers and are more likely to have modified their driving habits as a result. Snoring and daytime sleepiness should be further investigated as contributory factors to road tr

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00008.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The genetic architecture of narcolepsy is poorly known. Genetic and environmental components of symptoms characteristic of narcolepsy, excessive sleepiness and cataplexy were assessed in a population‐based sample of middle‐aged like‐sexed twin pairs. Questionnaire assessment of the 11‐item Ullanlinna Narcolepsy Scale (UNS), a validated screening instrument for narcolepsy [J. Sleep Res. (1994)3, 52–59] and two subscales (sleepiness and cataplexy‐like symptoms) was obtained from both twins of 3785 pairs aged 33–60 y (541 male MZ pairs, 1089 male DZ pairs, 781 female MZ and 1374 female DZ pairs) from the population‐based Finnish Twin Cohort. For the UNS scores, the intraclass correlation for male MZ pairs was 0.365 and for male DZ pairs 0.072, while for female pairs the MZ correlation was 0.375 and for DZ pairs 0.155. Structural equation model fitting indicated that a model with additive and non‐additive genetic effects, and idiosyncratic environmental effects best accounted for the pattern of twin resemblance in both men and women. Genetic effects accounted for 35% (in men) and for 39% (in women) of total phenotypic variance in UNS. Analysis of the subscales suggested that there may be a greater genetic component to the sleepiness subscale, while environmental components play more of a role in the development of cataplexy‐like symptoms. Further investigation of the complex genetic architecture of narcolepsy and its sy

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.d01-52.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The hypnotic action of melatonin 5 mg p.o. was explored in 15 subjects with psychophysiological insomnia in a double‐blind controlled self‐report questionnaire study. Melatonin or placebo was taken at 20.00 hours for a 1‐week period in random order. Effects on sleep and wakefulness were monitored by visual analogue scale and structured interview. Bedtime, sleep onset time, estimated total sleep and wake time, as well as self‐rated sleep quality, were not altered by melatonin, and estimates of next‐day function did not change. The period of melatonin treatment was retrospectively correctly identified by 8 of 15 subjects. Despite unchanged ratings of night sleep quality on the last night of each treatment, 7 of 15 subjects reported that sleep had subjectively improved to a minor extent in the week of active treatment. Side‐effects attributed to melatonin included headache and an odd taste in the mouth. These data indicate that melatonin is probably of no clinical value in the management of psychophysiologic

ISSN:0962-1105    

DOI:10.1046/j.1365-2869.1996.00003.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY