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Biomedical subjects

M H Bonnet

Publications and source records attributed to M H Bonnet.

71 records · Page 4Linked to original sources
PubMed1979

The return to sleep.

Six young adult subjects were awakened five to eight times per night from stage 2 sleep in a standardized manner for a series of at least 11 non-consecutive nights. After adaptation to the procedure, subjects received placebo, pentobarbital, or flurazepam on two random nights and caffeine on one night. The latency of the return to sleep after each awakening was measured. On placebo nights a characteristic U-shaped curve of latency as a function of time of night was found. Latencies were long shortly after sleep onset but decreased rapidly to about 50 sec before beginning an approximately linear logarithmic increase throughout the rest of the night. The drugs characteristically altered this time course. Pentobarbital decreased latencies in the first half of the night. Flurazepam decreased latencies throughout the night. Caffeine increased latencies during the first half of the night.

Adult↗
PubMed1979

Effect of flurazepam, pentobarbital, and caffeine on arousal threshold.

After laboratory and procedure adaptation, 6 normal subjects were randomly administered 30 mg flurazepam (twice), 100 mg pentobarbital (twice), 400 mg caffeine (once), and placebo (twice) on nonconsecutive nights. On each night subjects were aroused from standard segments of stage 2 sleep five to eight times with an ascending series of 1,000 Hz tones produced by an audiometer. Arousal threshold and awake threshold after each arousal were measured. Both thresholds were increased by flurazepam and pentobarbital and decreased by caffeine. All of the drugs appeared to modify arousal threshold in a time course fashion such that extreme effects were found during the first half of the night. However, the modifications of waking threshold by caffeine and flurazepam continued throughout the sleep period. The method may be a means of measuring the behavioral time course of drug activity during the sleep period.

Adult↗
PubMed1978

The sleep of 'morning' and 'evening' types.

A questionnaire developed by Ostberg to differentiate 'morning' types from 'evening' types was administered to 100 college students. The actual sleep behavior of the 11 extreme 'morning' types (larks) and the 10 extreme 'evening' types (owls) was monitored for two weeks with a sleep log and the Post-sleep Inventory. Data was collected from the owls for a further two-week period in which the owls had been instructed to attempt to arise at the lark arousal time. In addition to going to bed earlier and getting up earlier than the owls, the larks had a less variable sleep length and awakening time and took shorter naps than the owls. Larks further reported fewer physical problems and less mental activity across the night as well as more adequate sleep than owls, who differed little from the normal college population even after having their awakening time shifted.

Activity Cycles↗
PubMed1978

Relationship of arousal threshold to sleep stage distribution and subjective estimates of depth and quality of sleep.

The relationship of arousal threshold, amounts of various sleep stages, and subjective rating of sleep was studied in two separate experiments involving 7 and 26 young adult subjects, respectively. Electroencephalographic sleep stage data, subjective response data, and arousal threshold data were collected over a series of nights in the sleep laboratory. Only nonsignificant relationships were found between magnitude of arousal threshold and amounts of various sleep stages or subjective rating of sleep quality in between-subjects analyses. However, when the nights representing extremes in arousal threshold were examined within-subject, it was found that nights of high threshold were accompanied by subjective reports of significantly better sleep in both studies and by a significant decrease in the amount of stage W in one study. Arousal threshold was not related to subjective depth of sleep in either study. Rather, subjective ratings of depth of sleep were significantly related to the amount of EEG-defined wakefulness and stage 1.

Adolescent↗
PubMed1976

Effect of two experimental sets on sleep structure.

The effect of four perceptual sets--First Night in a sleep laboratory, Second Night in a sleep laboratory, Shock Avoidance Night, Reward Night--on the distribution of sleep was examined with 12Ss. Both the shock avoidance and the reward conditions gave results similar to those characteristically found in the First Night Effect, i.e., increases in Stage 0, Stage 1, the latency to Stage 4, the number of Awakenings, and the number of Stage Changes coupled with a decrease in Stage 1-REM. The observed effects, however, were minimal and were interpreted as giving evidence for the sturdiness of the sleep process.

Acoustic Stimulation↗
PubMedDate not supplied

Metabolic rate and the restorative function of sleep.

It has been shown that performance improves during sleep more rapidly after sleep deprivation than during normal sleep. Recovery after sleep deprivation is also characterized by a different sleep stage distribution and by a decreased metabolic rate compared to a normal night of sleep. The present study examined whether sleep during a period of increased metabolic rate was less restorative than a normal period of sleep. Twelve normal young adults participated for two 4-day periods. In each period, an undisturbed baseline sleep night was followed by baseline testing. On the subsequent night, Ss slept a total of 212 min, starting at 0200 h after consuming placebo or 400 mg of caffeine. After the nap, subjects remained awake for 41 h until beginning an undisturbed night of recover sleep. During the period of sleep loss, subjects remained at the sleep laboratory where they performed computer tests and MSLTs. The caffeine produced a significant increase in metabolic rate during the nap. Although total sleep time was held constant, there was an increase in stage 1 and a decrease in stage 4 sleep after caffeine use. Performance on addition and vigilance tasks was significantly decreased after the caffeine plus nap condition. However, no significant difference were found on the MSLT, and subjective vigor was significantly greater following the caffeine and nap combination. It was concluded that the beneficial effect of sleep in maintaining performance was decreased by increased physiological activation during sleep.

Adolescent↗
PubMedDate not supplied

Effect of 64 hours of sleep deprivation upon sleep in geriatric normals and insomniacs.

Fifty-eight geriatric normal and chronic insomniac sleepers were screened with sleep recordings to define groups of 12 Normal (Sleep Efficiency greater than 85%) and Insomniac (Sleep Efficiency less than 80%) sleepers. All subjects then had 4 baseline sleep nights, 64 hours of total sleep loss, and 4 recovery nights. Insomniacs, had lower sleep efficiencies and less REM than Normals during baseline. Sleep efficiency was high (97%) in both groups on the first recovery night but decreased toward baseline values in both groups between the second (Normal) and fourth (Insomniac) recovery night. The groups had relatively little slow wave sleep, but had a significant increase on the first recovery night. Five Normals and one Insomniac had REM latency of less than 15 min on their first recovery night. This REM latency was found to be significantly correlated with the amount of slow wave sleep on baseline. Decreased REM latency in initial recovery sleep was interpreted as evidence of decreased pressure for slow wave sleep in aging.

Aged↗
PubMedDate not supplied

Effects of irregular versus regular sleep schedules on performance, mood and body temperature.

Twelve male college students slept for 38 consecutive nights in the sleep laboratory under strict control of bedtime and wake-up time. Sleep logs, body temperature and performance on an experimenter-paced auditory vigilance and subject-paced addition test were assessed before sleeping in the laboratory, following 38 consecutive nights, and one month afterward to examine the effects of rigidly controlling retiring and awakening times. While large changes in the regularity of sleep occurred during sleep in the laboratory as compared to the normal irregular schedules, no significant changes in EEG sleep stage, performance, or mood were found. Body temperature was found to be higher and, perhaps, more flattened in the initial irregular condition as compared to the regular sleep schedule condition. It was concluded, however, that careful control of sleep and waking times in relatively irregular sleeping college students had little influence on sleep or performance. This finding implies that previous differences reported between groups of regular and irregular sleepers may have been based on personality differences rather than sleep scheduling factors.

Adult↗
PubMedDate not supplied

The relationship of sleep and anxiety in anxious subjects.

The present study provided polysomnographic corroboration of the frequently reported relationship between anxiety and subjective sleep disturbance. When compared to normals, anxious individuals were found to have significantly less sleep period time, total sleep time, percent stage REM and percent stage 4; shorter latency to stage REM; and greater percent stage 1. Partial correlations (holding depression constant) showed significant positive relationships between anxiety rating and number of awakenings, latency to stage 1, and percent stage 2. A significant negative relationship was found between anxiety and percent stage 4, and a nonsignificant negative trend was found between anxiety and latency to stage REM. Overall there was a tendency toward less sleep and lighter sleep in subjects with anxiety, thus validating subjective reports. The decreased latency to stage REM and its negative relation to anxiety, raised the possibility that this variable may not be specifically indicative of depression.

Adolescent↗
PubMedDate not supplied

The effect of sleep fragmentation on sleep and performance in younger and older subjects.

Groups of 12 normal 55-70-year-old and young adult subjects had their sleep experimentally disturbed at a rate of approximately 14 times per hour to determine the residual effects of moderate sleep disturbance and to determine any differential impact as a function of age. Normal age-related changes in sleep were seen on baseline and recovery nights. In the second night of sleep disturbance, the older subjects had a smaller increase in total awakenings than young adults. Older subjects had a slower increase in auditory arousal threshold as sleep disturbance progressed. The older subjects also tended to have less performance deterioration on morning testing than did young adults, and this difference was significant for numbers of correctly completed addition problems. These evidences led to the conclusion that, while both age groups were sensitive to moderate sleep disturbance, the older individuals appeared somewhat less sensitive than the young adults.

Adaptation, Physiological↗
PubMedDate not supplied

Physiological activation in patients with Sleep State Misperception.

OBJECTIVE: Sleep State Misperception insomnia has been commonly viewed as a perceptual or psychological problem. It was hypothesized that Sleep State Misperception insomnia, like psychophysiological insomnia, could be associated with increased physiological activation, here indexed by whole body metabolic rate. METHOD: Groups of nine patients with Sleep State Misperception insomnia and age-, sex-, and weight-matched normal sleepers were evaluated on sleep, performance, mood, personality, and metabolic measures over a 36-hour sleep laboratory stay. RESULTS: Sleep State Misperception insomniacs had a subjective history of poor sleep and perceived their laboratory sleep as poor but had electroencephalogram (EEG) parameters that did not differ statistically from matched normal controls. Sleep State Misperception insomniacs had abnormal MMPI values and were subjectively more confused, tense, depressed, and angry than matched normals. Sleep State Misperception insomniacs also had a significantly increased 24-hour metabolic rate, compared with matched normals. CONCLUSIONS: The overall increase in whole body oxygen use was less than that seen in psychophysiological insomniacs but was consistent with the view that Sleep State Misperception insomnia may be a mild version or a precursor to psychophysiological insomnia.

Adolescent↗
PubMedDate not supplied

Heart rate variability in insomniacs and matched normal sleepers.

OBJECTIVE: It was hypothesized that psychophysiological insomniacs, who have been shown to have elevated heart rate, body temperature, and whole body metabolic rate, would also have increased low frequency and decreased high frequency power in the spectral analysis of their heart period data. METHOD: Groups of 12 objectively defined insomniacs and age-, sex-, and weight-matched controls with normal sleep were evaluated on sleep and EKG measures over a 36-hour sleep laboratory stay. RESULTS: Heart period was decreased (ie, heart rate was increased) and its SD was decreased in all stages of sleep in the insomniacs compared with the controls. Spectral analysis revealed significantly increased low frequency power and decreased high frequency power in insomniacs compared with controls across all stages of sleep. CONCLUSIONS: Because increased low frequency spectral power is an indicator of increased sympathetic nervous system activity, these data imply that chronic insomniacs could be at increased risk for the development of disorders, such as coronary artery disease, that are related to increased sympathetic nervous system activity.

Adult↗
PubMedDate not supplied

Reported chronic insomnia is independent of poor sleep as measured by electroencephalography.

OBJECTIVE: Several behavioral, physiological, and subjective variables were examined in subjects reporting chronic insomnia (IN group) and subjects with no complaint of insomnia (NC group) to determine factors predictive of poor sleep as measured by electroencephalography (EEG sleep). METHODS: A total of 177 subjects (121 in the IN group and 56 in the NC group) were evaluated on the basis of EEG sleep, subjective sleep, sleepiness, performance, mood, personality, and metabolic parameters during a 36-hour laboratory stay. RESULTS: Equal percentages of subjects in each group had 0, 1, or 2 nights of poor EEG sleep, indicating that the IN group was not more likely to have impaired sleep in the laboratory. Results of the Minnesota Multiphasic Personality Inventory showed that subjects in the IN group had more pathological personality profiles, and results of laboratory studies showed that these subjects had worse mood ratings, less subjective sleepiness, poorer memory performance, and longer midafternoon sleep latencies. Subjects in the IN group also rated their laboratory sleep as poorer in quality with more time awake after sleep onset and longer sleep latencies, but no differences in EEG sleep were observed. Poor nights of EEG sleep were associated with being male, increasing age, and a history of more time awake after sleep onset; among the laboratory tests, poor EEG sleep was associated with worse mood ratings, poorer memory performance, longer sleep latencies (as indicated by higher scores on the Multiple Sleep Latency Test), higher sleep/wake ratios for metabolic parameters, lower ratings of sleep quality, and longer perceived sleep latencies. CONCLUSIONS: A history of chronic insomnia does not predict poor EEG sleep. Both chronic insomnia and poor EEG sleep are associated independently with dysphoria, hyperarousal, diminished waking function, and negative subjective sleep quality. Separate arousal and sleep systems are posited to account for these results.

Adolescent↗
PubMedDate not supplied

Intervention factors for promoting adjustment to nightwork and shiftwork.

This chapter reviews a broad range of factors that, if controlled, might promote adaptation to nightwork, shiftwork, and extended workshifts. Systematic study has begun in four of the areas reported here: work schedule design, napping, bright light stimulation, and drugs. Physical activity, ambient temperature, diet, and individual behaviors have been studied only superficially.

Adaptation, Physiological↗