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Biomedical subjects

M H Bonnet

Publications and source records attributed to M H Bonnet.

At least 55 records · Page 3Linked to original sources
PubMed1989

Sleep loss in aging.

Tests of performance and alertness in normal older subjects undergoing sleep loss reveal loss of performance and alertness similar to that seen in younger individuals. Recovery of performance ability occurs with one night of normal sleep, even following periods of sleep loss up to 64 hours in length. Older individuals, including older individuals with primary insomnia, may tolerate sleep loss with less decrease in ability compared with their baseline than young adults and may recover function more quickly than young adults. While it has been frequently shown that older individuals perform more poorly than young adults on a broad range of tasks, these findings do not hold well for periods of nocturnal performance or performance during sleep loss. It is possible that these findings may be accounted for to some extent by the decrease in amplitude of the circadian body temperature curve in older individuals. It is unfortunate that Reynolds et al did not attempt to collect performance data in their depressed and demented patients to determine if the differential effects on mood and EEG would also be reflected in psychomotor performance.

Adult↗
PubMed1988

The use of triazolam in phase-advanced sleep.

The need for optimal nocturnal performance continues to increase in our society. Nighttime function is dependent upon the ability to sleep effectively during the day. The current study examined daytime sleep after placebo, 0.125 mg (364 nmol), 0.25 mg (729 nmol), or 0.50 mg (1458 nmol) of triazolam, and nocturnal performance in the work shift that followed. Forty-one normal young adult subjects participated in a repeated-measures design in which each subject received each medication dose level in a separate week. The results indicated that day sleep increased as a linear function of drug dose from 234 to 374 minutes. Nocturnal alertness, as measured by subjective report and objective nap latency test, increased significantly following the use of triazolam, 0.25 and 0.50 mg, for the day sleep period. Nocturnal performance, as measured by auditory vigilance and additions, also increased significantly following the use of triazolam. Marginal evidence for medication hangover was found at the 0.50-mg dose, and it was therefore recommended that the use of the 0.50-mg dose be monitored carefully if performance demand were to follow medication use by less than 12 hours. The results for the study were interpreted as indicating that under certain conditions, triazolam could effectively increase daytime sleep and improve alertness and performance in the following nocturnal work period.

Adult↗
PubMed1987

Sleep and performance in young adults and older normals and insomniacs during acute sleep loss and recovery.

Many changes occur in sleep as a function of aging, but it is not known whether these changes result in sleep being less restorative. To examine the sleep restorative process, groups of 12 normal young adults and 12 normal and 12 insomniac male subjects, age 55-71, were totally sleep deprived for 64 hours and then allowed recovery sleep. Response speed, immediate recall, sleepiness, and body temperature were tested at approximately 2300, 0115, 0330, 0530 and 0800 during baseline, sleep loss, and recovery nights. Significant group (age or insomnia) by sleep loss condition interactions were found for reaction time and immediate recall performance measures. Similar significant interactions were found for oral temperature and all EEG sleep variables except total time in bed, percent stage 1, and percent REM. It was concluded that performance recovery following sleep loss was no slower in older subjects than in younger subjects despite very different recovery sleep stage parameters. This implied that aging effects on sleep are developmental rather than degenerative.

Adolescent↗
PubMed1987

Performance during frequent sleep disruption.

Performance on a simple addition task was measured during three schedules of frequent sleep disruption for 2 nights. Five young adults had their sleep briefly disturbed for 2 nights in 3 separate weeks either every 1 min, every 10 min, or at sleep onset after an undisrupted 2.5-h sleep period. Subjects were required to perform a two-number, two-digit addition problem as rapidly as possible on awakening. Main effects were found for sleep disruption condition and time of night, and a significant interaction between the two was also observed. Latency to response was longest for the 10-min condition on night 1, on night 2, however, response latencies were longest in the 1-min condition. Response latencies were fastest in the 2.5-h condition for both nights of disruption. Arousal thresholds were also gathered across both nights. Arousal thresholds were consistently the highest in the 1- and 10-min conditions for both nights of disruption, reaching maximum threshold levels at the end of night 1. Arousal threshold was significantly positively correlated with response latency. Sleep stages (slow-wave sleep (SWS), SWS + REM (SWSR), and total sleep time minus stage 1 sleep) were poor predictors of performance changes across the 2 disruption nights. The data were best explained by sleep continuity theory, which posits that a period of at least 10 min of uninterrupted sleep is required for restoration to take place.

Adolescent↗
PubMed1987

Sleep restoration as a function of periodic awakening, movement, or electroencephalographic change.

Eleven young adults had their sleep briefly disturbed following each 2 min of accumulated sleep for 2 consecutive nights in 3 different weeks. During 1 week the disturbance was a brief awakening followed by a subjective response. During another week subjects were required to make a quarter-body turn response. During the final week, the disturbance was an ongoing electroencephalographic (EEG) change. As expected, the three disturbance conditions differentially impacted sleep, with the most sleep disturbance seen in the awakening condition and the least disturbance seen in the EEG change condition. Morning vigilance performance and nap latency were decreased and fatigue was increased as compared with baseline following all three disturbance conditions. However, no significant condition interaction was found for any performance variable or for morning nap latency. For the mood scales, significant condition interactions indicated that subjects reported being sleepier only after the awakening condition. The data were interpreted as providing evidence that the restorative function of sleep is equally impaired by any periodic change in ongoing EEG and that impairment does not require a return to waking consciousness. However, mood, as a subjective rating, is dependent upon conscious events that occur during the sleep period.

Adolescent↗
PubMed1986

Auditory thresholds during continuing sleep.

Five subjects were asked to respond to a 1000 Hz tone with a standard button push response during sleep. A method of limits procedure was used to track their auditory thresholds when awake and during various stages of sleep. Subjects adapted to the procedure and were able to make consistent responses while their EEG indicated stage 1 or stage 2 sleep. While the threshold level at which a response was made was directly related to EEG state, there was no significant correlation between the interval between responses and the threshold level. It was concluded that stable auditory thresholds could be obtained during stage 1 and stage 2 sleep after little laboratory adaptation and that this behavioral response could be a useful indicator of central processing ability during sleep.

Acoustic Stimulation↗
PubMed1986

Performance and sleepiness following moderate sleep disruption and slow wave sleep deprivation.

Recent studies have shown that periodically disrupted sleep resulted in significant daytime sleepiness and performance loss in normal young adults. One study suggested that the periodicity of disturbance rather than the total number of sleep disturbances was the primary factor in causing degraded function. However, in that study, increased performance levels could have been associated with increased levels of slow wave sleep. The present study was designed to determine whether the amount of SWS rather than the periodic disruption of sleep accounts for decreased performance of Ss with disrupted sleep. Twelve normal young adults spent two 4-night periods in the laboratory. During one 4-night series, Ss were briefly aroused either following each 10 min of sleep or whenever they entered stage 3 sleep (No SWS condition). During the second series of nights, Ss were briefly aroused after each 10 min of sleep (SWS condition). In the second series, additional arousals were performed after 5-min periods (but not when Ss were in SWS) to equalize the total number of arousals in the SWS conditions with those in the No SWS condition. Total experimental arousals were equal in the disruption conditions, and the experimental manipulation was successful in reducing total SWS to infrequent epochs of stage 3 in the No SWS condition while allowing significantly more SWS in the SWS condition. In terms of sleep stages, this difference was balanced by increased stage 2 in the No SWS condition. Despite the differential occurrence of SWS, no performance, mood, or nap latency measure was different in the SWS vs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Effect of sleep disruption on sleep, performance, and mood.

Eleven young adult subjects were briefly awakened after each minute of electroencephalographic-defined sleep for 2 consecutive nights after undisturbed laboratory adaptation and baseline nights. Two undisturbed recovery nights followed disruption nights. On disruption nights, subjects were awakened with an audiometer and signaled the awakening by subjective rating of sleep state or button push response. The disruption procedure resulted in severely fragmented sleep with only very small amounts of slow-wave and REM sleep. Total sleep time was reduced by approximately 1 h on each night. Arousal threshold increased 56 dB across the disruption nights. Following disruption, subjects performed more poorly and rated themselves sleepier than on baseline. The level of decline was similar to that seen after periods of total sleep loss of 40-64 h. Recovery sleep was also similar to that seen after total sleep loss. It was concluded that periodic disruption of sleep, perhaps by destroying sleep continuity, quickly results in impaired function. These data may help explain function loss in severe sleep apneics.

Achievement↗
PubMed1985

Recovery of performance during sleep following sleep deprivation in older normal and insomniac adult males.

Groups of 12 normal and insomniac male subjects aged 55 to 71 yr. were sleep deprived for 64 hr. In both groups, the sleep loss was preceded by four baseline sleep nights and followed by four recovery nights. Reaction time, immediate recall, sleepiness, and body temperature were measured at approximately 2300, 0115, 0330, 0530, and 0800 during baseline, deprivation and recovery nights. Significant performance or mood differences were not found between the normal and insomniac males on any measure or at any testing period throughout the study. Performance of both groups declined characteristically during sleep loss while subjective sleepiness increased. As in young adults, degraded performance was restored by 8 hr. of recovery sleep. However, subjective sleepiness did not return to baseline levels until early in the second recovery night. It was concluded that chronic insomnia does not result in group performance deficits similar to those seen after chronic sleep loss; and the restorative function of sleep operates as efficiently in older insomniac subjects (who apparently have reduced need to sleep) as in older normal subjects.

Aged↗
PubMed1985

Sleep stages, auditory arousal threshold, and body temperature as predictors of behavior upon awakening.

Attempts to demonstrate sleep stage effects on waking behavior have been equivocal at best. The present study provided a more sensitive approach to this problem by assessing performance and subjective alertness at repeated awakenings across baseline sleep and across recovery sleep following 40 and 64 hours of sleep deprivation. These behaviors were then compared to changes in EEG sleep, body temperature, and auditory threshold within these nights. Comparison of means between baseline and recovery sleep indicated that the behavioral variables were generally more sensitive than sleep stages to different amounts of prior wakefulness. Multiple regression analyses revealed no consistent covariation between behavior and any sleep stage which was independent of the correlations among the sleep stages themselves. Thus, distinct functions for specific sleep stages were not apparent from the comparison of means or the regression analyses. However, significant positive covariations were obtained between body temperature and performance, and auditory threshold and sleepiness. Significant negative covariations were obtained between body temperature and sleepiness, and auditory threshold and performance. From these results it was concluded that the most reliable predictors of behavior upon awakening were: the amount of wakefulness prior to sleep, the total amount of accrued sleep, circadian time as indexed by body temperature, and depth of sleep.

Adolescent↗
PubMed1985

Sleep disorders: insomnias.

An inability to sleep or sleep prematurely ended or interrupted by periods of wakefulness (insomnia) are some of the most frequent complaints heard from patients. Insomnia can be situationally related or persistent in nature. Persistent insomnia may be associated with biological rhythm disturbances, drug dependency, psychophysiologic abnormalities, psychiatric disturbance, sleep apnea syndrome or nocturnal myoclonus. This article describes these pathologies, gives clues toward differential diagnosis, suggests patient subgroups that would benefit from referral for specialized evaluation at a sleep disorder center and describes current treatment options.

Biological Clocks↗
PubMed1982

The threshold of sleep: perception of sleep as a function of time asleep and auditory threshold.

A number of studies have found that many subjects have reported being awake when awakened during various periods of electroencephalographically (EEG)-defined sleep. These observations have led to an examination of the perception of sleep after periods when EEG-defined sleep was experimentally varied between 1 and 140 min. Twelve normal young adult subjects slept in the laboratory for 5 consecutive nights. Each subject was briefly awakened five times on each night, and subjective state, auditory arousal threshold, and sleep/wake time estimation data were collected. The threshold of sleep onset (i.e., the point at which a report of sleep was given 50% of the time) occurred 2-4 min after the first sleep spindle. In contrast, auditory thresholds rose rapidly within 1 min of the first sleep spindle. The threshold data corroborate the appearance of a sleep spindle as an objective measure of sleep onset. However, subjective sleep onset appears to be a relatively lengthy period during which perception of state is blurred and uncertain.

Adolescent↗
PubMed1981

A dose response study of the hypnotic effectiveness of alprazolam and diazepam in normal subjects.

One group of eight normal young males was administered three doses of alprazolam (0.25, 0.5 and 1.0 mg) and placebo, while a second group of eight normal young males was given three doses of diazepam (2, 5, and 10 mg) and placebo in the same design. All subjects slept in the sleep laboratory for 10 nights, 2 consecutive nights each week for 5 consecutive weeks. The first 2 nights served as adaptation. During the next 4 weeks subjects received a random dose of alprazolam (or placebo) or a random dose of diazepam (or placebo) each week. Similar dose-related benzodiazepine effects were found on sleep with both medications. Alprazolam reduced percent stage 4 and REM sleep and increased stage 2 sleep and latency to REM. Diazepam decreased percent stage 1 and increased percent stage 2 sleep. No drug by dose interactions were found. It was concluded that, while both drugs had similar effects on sleep, alprazolam showed significant effects on REM sleep parameters and might be evaluated for possible antidepressant effect.

Adolescent↗
PubMed1981

The interaction of age, performance and hypnotics in the sleep of insomniacs.

Scant attention has been paid to the objective evaluation of insomnia as a function of age, particularly with reference to increased drug sensitivity and resulting loss in balance performance. Therefore, the electroencephalographic sleep and the balance-board performance of 10 young and 12 geriatric insomniacs were studied under baseline and hypnotic drug (ketazolam) conditions. In terms of objectively measured sleep, the geriatric insomniacs had worse sleep on every dimension except sleep latency and percentage of stage-2 sleep. These differences between aged and young insomniacs, however, were no greater than might be expected as a function of normal aging. Drug-age interactions indicated that ketazolam differentially increased sleep efficiency, decreased the percentage of REM sleep, and eliminated any learning improvement on the balance board in geriatric versus young insomniacs. The findings indicate that the geriatric subjects were more sensitive to the hypnotic drug, in that their sleep improved to a greater extent. However, an important loss in balance performance was also observed.

Adult↗