Showing papers on "Non-rapid eye movement sleep published in 1988"
TL;DR: Standardized cephalometric roentgenograms can be useful in determining the appropriate treatment for OSAS patients, and long mandibular plane to hyoid bone distance and width of the posterior airway space (PAS) were statistically significant predictors of elevated RDI.
277 citations
TL;DR: The delayed sleep phase syndrome is characterized by difficulty in falling asleep at a socially acceptable time of night and an inability to be easily aroused in the morning and may contribute to the behavioral and educational difficulties seen in patients.
195 citations
TL;DR: It is suggested that the frontal and parietal major negative peaks ('N18' and 'N20') consist of multiple physioanatomical substrates mediated through complex thalamocortical projection systems, and that the FFP are closely related to the sleep-wake mechanism possibly reflected by mutual interaction between cortex and the thalamic reticular system.
179 citations
TL;DR: The data suggest a functional correlation between the control mechanisms of CAP and the organization of sleep, and morphological and behavioural analogies with some phasic phenomena reported in the literature.
173 citations
TL;DR: It is concluded that the site of inspiratory narrowing within the upper airway during sleep occurs primarily at either the level of the palate or hypopharynx and is variable among subjects.
Abstract: In order to determine the specific site of inspiratory narrowing within the upper airway during sleep, we measured supralaryngeal, oropharyngeal, and nasopharyngeal pressures and inspiratory flow in 11 healthy nonsnoring male subjects awake and in NREM sleep. Resistance was calculated at 0.01 L/s, a point along the linear portion of the pressure-flow relationship, and at peak inspiratory pressure, a point within the curvilinear section of the pressure-flow relationship. During sleep, nasal resistance increased minimally. At peak inspiratory pressure, both transpalatal and hypopharyngeal resistances increased more than 700% in NREM sleep. At 0.01 L/s inspiratory flow, transpalatal and hypopharyngeal resistances increased 200 and 400%, respectively. Six subjects had a greater increase in transpalatal than hypopharyngeal resistance, and five subjects had a greater increase in hypopharyngeal than transpalatal resistance. Three subjects in each of these two subgroups had an increase in resistance exclusively across the palate or the hypopharynx. The site of increased resistance during sleep was not predictable from awake resistance measurements. From these data, we conclude that the site of inspiratory narrowing within the upper airway during sleep occurs primarily at either the level of the palate or hypopharynx and is variable among subjects. The pattern of palatal or hypopharyngeal narrowing is the same as that observed in obstructive sleep apnea patients, but quantitatively different.
145 citations
TL;DR: AD is longer in REM than NREM, regardless of position, and AHI is higher on the back only in NREM; however, favoring the lateral decubitus position may not be as beneficial as previously thought in very obese patients.
Abstract: In patients with obstructive sleep apnea, it is believed that body position influences apnea frequency. Sleeping in the lateral decubitus position often results in significantly fewer apneas, and some have recommended sleeping on the side as the major treatment intervention. Previous studies, although calculating apnea-hypopnea index (AHI) for supine and lateral decubitus positions, have not taken sleep stage into account. To examine the effect of both sleep stage and body position on apnea duration (AD) and frequency, we determined AHI and AD in all spontaneous body positions during rapid eye movement (REM) and non-REM (NREM) sleep by reviewing videotapes and polysomnograms from 11 overnight studies of 7 obese patients with severe sleep apnea. Consistent with previous work, AD was significantly longer in REM then in NREM (32.5 +/- 2.3 s versus 23.5 +/- 1.9 s; p less than 0.05). This difference persisted when adjusting for body position. AHI was greater on the back than on the sides (84.4 +/- 4.9/h versus 73.6 +/- 7.5/h, p less than 0.05), but after accounting for sleep stage, this difference remained only for NREM (103 +/- 4.8/h versus 80.3 +/- 9.2/h, p less than 0.05) and not for REM (83.6 +/- 5.3/h versus 71.1 +/- 4.2/h, p NS). Although reduced, AHI on the sides still remained clinically very high. Body position changed frequently throughout the night, but some patients spent little or no time on their back. We conclude that AD is longer in REM than NREM, regardless of position, and AHI is higher on the back only in NREM. As AHI remains very high on the sides, favoring the lateral decubitus position may not be as beneficial as previously thought in very obese patients. Less obese patients are more likely to benefit by position changes.
135 citations
TL;DR: The marked 24-h variation of maximum slow-wave activity within NREMS episodes may reflect the level of a homeostatic sleep process.
Abstract: Sleep states and power spectra of the electroencephalogram were determined for consecutive 4-s epochs during 24 h in rats that had been implanted with electrodes under deep pentobarbital anesthesia. The power spectra in non-rapid eye movement sleep (NREMS) showed marked trends: low-frequency activity (0.75-7.0 Hz) declined progressively throughout the 12-h light period (L) and remained low during most of the 12-h dark period (D); high-frequency activity (10.25-25.0 Hz) rose toward the end of L and reached a maximum at the beginning of D. Within a single NREMS episode (duration 0.5-5.0 min), slow-wave activity (0.75-4.0 Hz) increased progressively to a plateau level. The rise was approximated by a saturating exponential function: although the asymptote level of the function showed a prominent 24-h rhythm, the time constant remained relatively stable (approximately 40 s). After short interruptions of NREMS episodes, slow-wave activity rose more steeply than after long interruptions. The marked 24-h variation of maximum slow-wave activity within NREMS episodes may reflect the level of a homeostatic sleep process.
125 citations
Journal Article•
TL;DR: One hypothesis is that a subgroup of asthmatic patients with small pharynxes may have enhanced vagal stimulation during sleep compared with other astHmatic patients, related to the repetitive Müller manoeuvres noted with airway obstruction during sleep.
Abstract: We studied two populations of patients who snored and had frequent nocturnal asthma attacks: ten overweight men presenting with typical obstructive sleep apnoea syndrome, and a group of five adolescents with regular snoring and an increase in negative inspiratory oesophageal pressure during stage II non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. All subjects presented cranio-mandibular abnormalities at cephalometric evaluation, with a narrow space behind the base of the tongue. Both populations were treated with nasal continuous positive airway pressure (CPAP) during sleep. Snoring and partial or complete airway obstruction were eliminated, as were the nocturnal asthma attacks. Two adolescents treated with upper airway surgery after nasal CPAP showed no nocturnal asthma at short-term follow-up. Nasal CPAP had no effect on daytime asthma. One hypothesis is that a subgroup of asthmatic patients with small pharynxes may have enhanced vagal stimulation during sleep compared with other asthmatic patients. This enhancement would be related to the repetitive Muller manoeuvres noted with airway obstruction during sleep. Combined with the local effects of snoring, this extra vagal stimulation would be a precipitating factor in nocturnal asthma attacks.
114 citations
TL;DR: Observations support the hypothesis that poor load compensation for increased upper airway resistance contributes to the hypoventilation characteristic of normal sleep.
Abstract: Since upper airway resistance is known to increase during sleep, inadequate resistive load compensation may contribute to the normal decline in sleeping ventilation. We determined the acute and sustained (4 min) ventilatory response to a range of external inspiratory resistive loads (4, 8, 12, and 25 cmH2O.l-1.s) during wakefulness and non-rapid-eye-movement (NREM) and rapid-eye-movement (REM) sleep in seven normal men. We found that minute ventilation (VI) was well maintained with acute and sustained resistive loading during wakefulness. Immediate adjustments in ventilatory timing (prolongation of inspiratory duration) provided full compensation for airflow reduction. In marked contrast, resistive load application during NREM sleep invariably produced a significant (P less than 0.05) reduction in VI with progressively larger resistive loads producing progressively greater ventilatory decrements. This decline in ventilation was a product of a falling inspiratory flow rate with inadequate prolongation of inspiratory duration (TI). The largest decrements in ventilation occurred immediately after load application followed by partial ventilatory recovery, which occurred over time in concert with rising PCO2 and augmented ventilatory effort (as reflected by P0.1 or mouth occlusion pressure). Similar observations were made during REM sleep, although the responses were less consistent and fewer data were obtained. These observations support the hypothesis that poor load compensation for increased upper airway resistance contributes to the hypoventilation characteristic of normal sleep.
113 citations
TL;DR: The results suggest that spontaneous oscillations in ventilation are common during sleep and can be converted to periodic breathing with apnea when loop gain is increased.
Abstract: To determine the effect of respiratory control system loop gain on periodic breathing during sleep, 10 volunteers were studied during stage 1-2 non-rapid-eye-movement (NREM) sleep while breathing r...
112 citations
TL;DR: In order to investigate the effects of on-call duty on sleep and wakefulness, five male ships' engineers were studied using electroencephalogram (EEG) and electrocardiogram (ECG) recordings and subjective ratings.
Abstract: In order to investigate the effects of on-call duty on sleep and wakefulness, five male ships' engineers were studied using electroencephalogram (EEG) and electrocardiogram (ECG) recordings and subjective ratings. Sleep during on-call nights (two alarms) was shortened and contained less slow wave sleep (SWS) and rapid eye movement (REM) sleep, lower spectral power density, and a higher heart rate. Many of the effects were observable before any alarms had occurred. Rated sleep quality was lower, and sleepiness was higher during the subsequent day. It was suggested that the effects were due to apprehension/uneasiness induced by the prospect of being awakened by an alarm.
TL;DR: Electroencephalographic sleep patterns were examined in unmedicated patients meeting DSM-III-R criteria for a current manic episode to suggest that mania is associated with marked disturbances of sleep continuity and REM measures.
Abstract: • Electroencephalographic (EEG) sleep patterns were examined in nine unmedicated patients meeting DSM-III-R criteria for a current manic episode (four men and five women) for two to four consecutive nights. Compared with age- and sex-matched normal control subjects, manic patients exhibited significantly decreased total recording period, decreased time spent asleep, increased time awake in the last two hours of recording, shortened rapid eye movement (REM) latency, increased REM activity, and increased REM density. These results suggest that mania is associated with marked disturbances of sleep continuity and REM measures. Sleep continuity and REM sleep abnormalities of a similar nature and degree have been reported in major depression and psychotic depression. Thus, it is possible that various forms of affective disorders and psychotic disorders have pathophysiologic mechanisms in common.
TL;DR: The sleep-induced increase in upper airway resistance accompanied by the absence of immediate load compensation is an important determinant of CO2 retention, which, in turn, may cause augmentation of inspiratory and expiratory muscle activity above waking levels during NREM sleep.
Abstract: We hypothesized that a sleep-induced increase in mechanical impedance contributes to CO2 retention and respiratory muscle recruitment during non-rapid-eye-movement (NREM) sleep. The effect NREM sleep on respiratory muscle activity and CO2 retention was measured in healthy subjects who increased maximum total pulmonary resistance (RLmax, 1-81 cmH2O.l-1.s) from awake to NREM sleep. We determined the effects of this sleep-induced increase in airway impedance by steady-state inhalation of a reduced-density gas mixture (79% He-21% O2, He-O2). Both arterialized blood PCO2 (PaCO2) and end-tidal PCO2 (PETCO2) were measured. Inspiratory (EMGinsp) and expiratory (EMGexp) respiratory muscle electromyogram activity was measured. NREM sleep caused 1) RLmax to increase (7 +/- 3 vs. 39 +/- 28 cmH2O.l-1.s), 2) PaCO2 and/or PETCO2 to increase in all subjects (40 +/- 2 vs. 44 +/- 3 Torr), and 3) EMGinsp to increase in 8 of 9 subjects and EMGexp to increase in 9 of 17 subjects. Compared with steady-state air breathing during NREM sleep, steady-state He-O2 breathing 1) reduced RLmax by 38%, 2) decreased PaCO2 and PETCO2 by 2 Torr, and 3) decreased both EMGinsp (-20%) and EMGexp (-54%). We concluded that the sleep-induced increase in upper airway resistance accompanied by the absence of immediate load compensation is an important determinant of CO2 retention, which, in turn, may cause augmentation of inspiratory and expiratory muscle activity above waking levels during NREM sleep.
TL;DR: Electroencephalographic sleep recordings, as well as other laboratory tests, may help the clinician to differentiate anxiety from depressive disorders.
Abstract: Sleep polygraphic recordings were performed during 3 consecutive nights in 12 inpatients with generalized anxiety disorder (GAD) in comparison with age- and sex-matched groups of patients with major depressive disorder (MDD) and normal subjects GAD patients differed significantly from those with MDD A lower number of awakenings and stage shifts in night 1 and the mean of the 3 nights and a shorter rapid eye movement (REM) duration in night 1 but longer REM latency in the mean of the 3 nights were observed in GAD in comparison to MDD GAD patients also showed a significantly longer sleep onset latency and shorter duration of total sleep time and Stage 2 than control subjects Electroencephalographic sleep recordings, as well as other laboratory tests, may help the clinician to differentiate anxiety from depressive disorders
TL;DR: There was a significant negative correlation between response to PSD and sleep duration, and in particular, REMSleep duration, in the late sleep deprivation situation, and the amount and timing of sleep appear to be factors in the response toPSD.
Abstract: — The antidepressant response to partial sleep deprivation early in the night (PSD-E) was compared with the response to partial sleep deprivation late in the night (PSD-L) in 16 drug-free depressed inpatients using a balanced order crossover design. PSD-L had a significantly greater antidepressant effect that PSD-E. The response to PSD-L was sustained and enhanced by a second night of treatment. Patients had significantly shorter sleep durations and reduced REM sleep on PSD-L that did not occur in the PSD-E situation. There was a significant negative correlation between response to PSD and sleep duration, and in particular, REM sleep duration, in the late sleep deprivation situation. Thus, the amount and timing of sleep appear to be factors in the response to PSD, but additional studies are needed to evaluate the relative importance of these parameters.
TL;DR: It is suggested that the serotonergic system has a pervasive influence throughout the sleep-wakefulness continuum, in contrast with some other neurotransmitter systems, which may be more concerned with the subtle manifestations of vigilance.
TL;DR: Spontaneous and provoked awakenings blunted the rise in PRA normally associated with NREM sleep, which indicates that disturbing sleep modifies the renin release from the kidneys.
Abstract: To establish the strength of the relationship between the nocturnal oscillations in plasma renin activity (PRA) and the sleep stage patterns, 42 PRA profiles from blood collected at 10-min intervals and the concomitant polygraphic sleep recordings were analyzed. In all cases, PRA curves exactly reflected the pattern of sleep stage distribution. When sleep cycles were complete, PRA levels oscillated at a regular 100-min period, with a strong spectral density. Declining PRA levels always coincided with REM sleep phases and increasing levels with NREM sleep phases. More precisely, peak levels corresponded to the transition from deep sleep stages toward lighter ones. The start of the rises in PRA generally marked the transition from REM sleep to stage 2. For incomplete sleep cycles, PRA curves reflected all disturbances and irregularities in the sleep structure. Spontaneous and provoked awakenings blunted the rise in PRA normally associated with NREM sleep, which indicates that disturbing sleep modifies the renin release from the kidneys. These results suggest that a common mechanism within the central nervous system controls both PRA oscillations and the REM-NREM sleep alternation.
TL;DR: The results extend previous observations that hibernation is not a homogeneous state and suggest that deep torpor consists primarily of a state similar to NREM sleep, interrupted periodically by short intervals of a form of AW.
Abstract: Changes in arousal state in a euthermic mammal exert powerful influences on major neural regulatory systems. Changes in behavioral state occur at body temperature (Tb) greater than 25 degrees C during hibernation. However, no information exists regarding alterations in arousal states during deep torpor. In this study we used a combination of electroencephalographic, electromyographic, and posterior thalamic neuronal activity in ground squirrels (Spermophilus lateralis) to evaluate arousal states during deep hibernation. No state homologous to rapid-eye-movement sleep was observed below Tb = 21 degrees C during hibernation. However, the animals did continue to cycle through states homologous to electrophysiologically defined wakefulness (AW) and non-rapid-eye-movement (NREM) sleep at all temperatures examined (Tb = 14-36 degrees C). These results extend previous observations that hibernation is not a homogeneous state. Instead, deep torpor consists primarily of a state similar to NREM sleep, interrupted periodically by short intervals of a form of AW. These periodic alterations in state should be accompanied by changes in the properties of many regulatory systems and must be accounted for in any theory of the neural control of hibernation.
TL;DR: The possibility that circadian patterns of sleep/wake derive partly from circadian timing of waking behaviors that are incompatible with sleep, such as locomotor activity, is examined and elderly humans may benefit from therapies that augment daytime activity.
TL;DR: Polysomnographic data indicate a decrease in first REM latency, an absence of stage 4 NREM, altered phasic motor activity and behavioral episodes during REM sleep even with normal chin muscle atonia in patients with REM parasomnia.
Abstract: REM sleep behaviors were recently described as wild, dream-enacting behaviors during REM sleep with loss of usual atonia on submental muscles. We examined 6 patients (5 M, 1F) with characteristic episodes of behavioral manifestations during REM sleep. Polysomnographic data indicate a decrease in first REM latency, an absence of stage 4 NREM, altered phasic motor activity and behavioral episodes during REM sleep even with normal chin muscle atonia. Three patients had Shy-Drager syndrome, 1 olivopontocerebellar atrophy and 2 patients had no neurological disease. The crucial importance of a disinhibited locomotor system during sleep appears to be responsible for this REM parasomnia.
TL;DR: A common pattern of reduction in both rapid eye movement and non-rapid eye movement sleep associated with various lateral gaze paralyses was present in four cases of brain-stem stroke and was compared with lesions obtained experimentally in cats.
Abstract: • A common pattern of reduction in both rapid eye movement and non—rapid eye movement sleep associated with various lateral gaze paralyses was present in four cases of brain-stem stroke. From computed tomographic scan data, clinical inferences, and, in two cases, neuropathologic sections, the common lesions were localized in the medial pontine tegmentum, ie, the inner part of the gigantocellular and pontis centralis caudalis nuclei. These data in humans were compared with lesions obtained experimentally in cats.
TL;DR: Genioglossus responses to airway occlusion in REM sleep were similar in pattern to those in NREM sleep, and a relatively small reflex activation of upper airway muscles associated with a sudden increase in subatmospheric pressure in the potentially collapsible segment of theupper airway may help compromise upper airways patency during sleep.
Abstract: To determine the combined effect of increased subatmospheric upper airway pressure and withdrawal of phasic volume feedback from the lung on genioglossus muscle activity, the response of this muscle to intermittent nasal airway occlusion was studied in 12 normal adult males during sleep. Nasal occlusion at end expiration was achieved by inflating balloon-tipped catheters located within the portals of a nose mask. No seal was placed over the mouth. During nose breathing in non-rapid-eye-movement (NREM) sleep, nasal airway occlusion resulted in multiple respiratory efforts before arousal. Mouth breathing was not initiated until arousal. Phasic inspiratory genioglossus activity was present in eight subjects during NREM sleep. In these subjects, comparison of peak genioglossus inspiratory activity on the first three occluded efforts to the value just before occlusion showed an increase of 4.7, 16.1, and 28.0%, respectively. The relative increases in peak genioglossus activity were very similar to respective increases in peak diaphragm activity. Arousal was associated with a large burst in genioglossus activity. During airway occlusion in rapid-eye-movement (REM) sleep, mouth breathing could occur without a change in sleep state. In general, genioglossus responses to airway occlusion in REM sleep were similar in pattern to those in NREM sleep. A relatively small reflex activation of upper airway muscles associated with a sudden increase in subatmospheric pressure in the potentially collapsible segment of the upper airway may help compromise upper airway patency during sleep.
TL;DR: The electroencephalographic sleep profile of a group of recurrent depressives who had been depressed for less than four weeks was compared with their sleep profile in a prior episode of depression, indicating that early in the episode, rapid eye movement (REM) sleep findings are more abnormal.
Abstract: The electroencephalographic sleep profile of a group of recurrent depressives who had been depressed for less than four weeks was compared with their sleep profile in a prior episode of depression. The findings in these 19 cases indicate that early in the episode, rapid eye movement (REM) sleep findings are more abnormal, including shortened REM latency, REM sleep percent, and REM activity. Other sleep variables, such as sleep continuity measures and decreased delta-wave sleep, are abnormal in a similar fashion in both episodes. The results are not explainable on the basis of clinical severity or number of episodes and call for increased attention to the potential relationships between the psychobiological pattern and duration and course of the depressive episode.
TL;DR: Results of the present study agree well with those of studies using other cholinomimetics and confirm the importance of the cholinergic system for REM sleep regulation and play a role in the pathogenesis and pathophysiology of depressive diseases.
Abstract: In 36 healthy control subjects (21 females, 15 males; age range 18-65 years; mean age 41.8 years, SD 15.6 years), a bedtime dose of 1.5 mg RS 86, an orally acting cholinergic agonist, shortened rapid eye movement (REM) latency, increased REM sleep, and decreased slow-wave sleep. Six of the subjects (greater than 40 years old) even displayed sleep-onset REM periods after the drug. Results of the present study agree well with those of studies using other cholinomimetics (i.e., physostigmine, arecholine) and confirm the importance of the cholinergic system for REM sleep regulation. Since RS 86 mimicked some of the REM sleep abnormalities specific for patients with depressive disorders, the cholinergic system may play a role in the pathogenesis and pathophysiology of depressive diseases.
TL;DR: The results of this experiment support other data that indicate that NREM-P1 plays a special role in human sleep: it responds selectively to sleep deprivation, shows the greatest ontogenetic variation across the human lifespan, and is the component of sleep that is most frequently abnormal in psychiatric patients.
Abstract: In one of a series of experiments aimed at gathering the empirical data required to formulate mathematically our recovery model of sleep, we recently (1) measured the increase in delta electroencephalogram (EEG) following one night of total sleep deprivation (TSD). We found that the delta rebound was confined to the first non-rapid eye movement period (NREM-P1) of recovery sleep; this unexpected result was documented with direct computer measurement of 0-3 Hz EEG, as well as with visual scoring of stages 3 and 4. We also found a robust decrease in eye movement density during the second and third REM periods, which we hypothesized to be due to the increased depth of recovery sleep. In the present experiment, we awakened young adult subjects after 100 min of sleep, a duration that includes the first cycle for this age group, and analyzed visual and computer measures of delta and eye movement density during recovery sleep. We again found eye movement density to be significantly reduced in REM-P2 and P3, but to a lesser degree than after total sleep deprivation, a condition that may be presumed to produce a greater increase in sleep depth. Delta increases were again limited to the first cycle, although all subjects completed this cycle on the 100-min night. The major difference between recovery sleep patterns following the total deprivation and the 100-min sleep conditions was that 0-3-Hz wave amplitude increased significantly after the former, but not after the latter. In both studies, recovery sleep showed increased 0-3-Hz wave density. The neurophysiological implications of a response of EEG amplitude as opposed to wave density are briefly considered; separate measurement of these variables is more readily accomplished with period-amplitude than with spectral analysis. Our results further illustrate the importance of measuring sleep by physiological units, such as the successive NREMPs and REMPs. They also support other data that indicate that NREM-P1 plays a special role in human sleep: it responds selectively to sleep deprivation, shows the greatest ontogenetic variation across the human lifespan, and is the component of sleep that is most frequently abnormal in psychiatric patients. As we have long argued, it is inappropriate to conceptualize this high priority component of NREM sleep as "REM latency" and as a measure of REM "pressure" exclusively.
TL;DR: Physiological hypnic myoclonus was quantified during wakefulness and sleep in 7 normal subjects and increased during stage 1 and especially REM sleep, while in some muscles, however, it showed no increase during sleep.
TL;DR: There are, however, several components of REM and non-REM sleep, as well as a transitional state (indeterminate sleep) and abrupt alterations of state (arousal).
Abstract: Recent discussions of the functional significance of ultradian rhythms emphasize their importance to human physiology. Over the past 25 years, electroencephalographic (EEG) sleep patterns have been used in assessing the cerebral and central nervous system maturation of neonates. Through an interdisciplinary effort, spectral (Fourier) methods have been developed to discriminate between the various stages of sleep based on EEG recordings. Nevertheless, there has been little effort to develop methods for the statistical analysis of sleep-state cycling. In particular, attention has primarily been focused on the ultradian rhythm of sleep as it cycles between two states, active or rapid eye movement (REM) and quiet or non-REM sleep. There are, however, several components of REM and non-REM sleep, as well as a transitional state (indeterminate sleep) and abrupt alterations of state (arousal). Moreover, few studies have investigated the effects of prenatal alcohol exposure on the neurophysiological devel...
TL;DR: Sleep length and sleep quality scores were collected on board ships over periods of up to two weeks from 38 watchkeepers working a ‘4-on/8-off routine’ and 29 dayworkers, indicating a lack of adaptation of the sleep/wakefulness cycle to the hours of work.
Abstract: Sleep length and sleep quality scores were collected on board ships over periods of up to two weeks from 38 watchkeepers working a '4-on/8-off routine' and 29 dayworkers. All watchkeepers exhibited fragmented sleeping patterns, which indicated a lack of adaptation of the sleep/wakefulness cycle to the hours of work. There were only slight differences in total sleep length between watchkeepers and dayworkers, however, both groups did not obtain an adequate amount of sleep. Within the watchkeeping crews the 3rd Officers had by far the shortest sleep length. Concerning sleep quality, daytime sleep was generally given the lowest ratings, whereas sleep starting before midnight was on average evaluated as the best, both by watchkeepers and dayworkers. Watchkeeping personnel do not normally have any "days off" during a voyage so that missed sleep might even amount to a sleep deficit. A solution for this problem could perhaps be a new, stabilized system that allows a single uninterrupted sleep, which is required for full recuperation, to be taken each day. Language: en
TL;DR: The data confirmed earlier observations linking the appearance of slow rolling eye movements with drowsiness and the disappearance of them with the beginning of behaviorally defined sleep.
Abstract: The convergence of behavioral, EEG, and respiratory measures has been shown to increase the accurate detection of sleep onset (SO) (Ogilvie, 1985; Ogilvie & Wilkinson, 1984). The present investigation used a behavioral response (BR) measure and standard EEG indices to examine slow eye movement (SEM) activity during the transition from wakefulness to sleep. Several methods of scoring and assessing slow eye movements were employed in order to determine their usefulness as an index in the detection of sleep onset. Correlations between SEM activity and behavioral and EEG sleep stages were low to moderate. In multiple regression analyses, slow eye movements were shown to be a fairly stable but less powerful predictor of sleep onset than either behavioral or EEG measures. The data confirmed earlier observations linking the appearance of slow rolling eye movements with drowsiness and the disappearance of them with the beginning of behaviorally defined sleep. In most people this pattern is consistent enough to be useful in studying sleep onset. The applicability of this measure as a co-indicator of sleep onset was discussed.
Journal Article•
TL;DR: The response to the submaximal exercise was an increase in stage 2 NREM sleep and a decrease in slow-wave sleep (SWS) which is possibly indicative of a stress effect and in the trained compared to the untrained state, SWS was significantly higher after an exercise load.
Abstract: We studied the sleep patterns of nine young women when sedentary (untrained) and following a 12 week physical fitness training programme. A comparison of baseline sleep patterns and of sleep patterns following one hour of submaximal exercise performed in the evening was carried out at 0 and 12 weeks. The submaximal exercise task was for each subject to cycle for one hour at 70% of her maximal oxygen consumption (VO2 max) as measured when untrained and on completion of the training programme respectively. Changes in fitness were assessed by changes in VO2 max and anaerobic threshold (AT). On the day leading to the all night baseline sleep recordings the subjects carried out their normal daily routines and did no specific exercise. Lean body mass (LBM) was calculated from total body potassium measurements before and after training. A significant improvement in cardiorespiratory fitness did not result in any changes in baseline sleep parameters. The response to the submaximal exercise was an increase in stage 2 NREM sleep and a decrease in slow-wave sleep (SWS, stages 3 & 4) which is possibly indicative of a stress effect. However, in the trained compared to the untrained state, SWS was significantly higher after an exercise load.