Sleep Inertia Journal Evaluation
The title of the article is “Sleep Inertia Varies with Circadian Phase and Sleep Stage in Older Adults” written by Edward J. Silva and Jeanne F. Duffy. The purpose of the study was to examine if much older adults display the impacts of sleep inertia on performance at the planned wake up time. The study also determines if these impacts are subject to circadian stage or sleep period wakening.
Summary of Prior Research
Previous research on sleep inertia shows that transitioning from sleeping to waking up cannot be regarded as an instant adjustment from one state to a different one but rather is a course that takes a while to complete. Several experimental models have been used to research sleep inertia and one of the methodologies that have been used is the use of sudden wakening by audible provocations. Such studies have been used to examine sleep inertia after wakening at night time and dozes during the day (Silva & Duffy 2008). Results for such a study showed that as sleeplessness before taking a nap became greater, the impacts of sleep inertia also became greater. This increased the awakening performance impairment by lengthening the wake periods before the nap. Research also shows that the deeper the phase of sleep before awakening from the doze off, the lesser the wake performance. A study conducted on young subjects showed that the impacts of sleep inertia on routine on wakening from stage two non-rem sleep were extra evident compared to the ones after awakening from REM sleep. These studies showed that the importance of having a nap to counter routine deficiencies because of sleep loss has to be evaluated against routine deficiencies because of sleep inertia after waking up from the nap.
Despite these methodologies being applied practically, they might not be pertinent in comprehending the impacts of sleep inertia from performance wakening. Research from a group of young subjects about the impacts of sleep inertia indicated that performance straightway after awakening from an eight hour sleep at night at the usual time for bed was poorer than routine after a twenty-six hour of sleep deficiency. Much of the prior research has been conducted on young subjects and there is no clarity on if there are sleep inertia impacts on routine on older subjects (Silva & Duffy 2008). Also not clear is if the sleep inertia affects performance exists, what aspects affect the magnitude of performance deficiencies because of sleep inertia. Aging is connected to fluctuations in sleep quality and that the pervasiveness of reported sleep complaints such as not being able to maintain sleep, waking up early, and being sleepy during the day all increase with age. Compared to young subjects, subjective evaluations of early morning wakening and objective measures of sleep periods and consolidation show that older subjects find it more difficult to maintain sleep when it is planned at different circadian stages.
Participants
The participants included ten healthy older adults ranging from the ages of fifty-five to seventy-two whereby five were men and the other five were women. All the participants volunteered for the study. They were all evaluated medically and psychologically through a screening assessment before the study (Silva & Duffy 2008). Participants had to have a sleep duration between seven and ten hours and were not supposed to have any serious sleep grievances. They were all assessed for sleep conditions before being admitted. For three weeks before the study, the participants were not to take caffeine, nicotine, alcohol, and any medication. Those who complied with these criteria were verified by a urine analysis upon admission. Each subject had to provide written consent before the start of the study. The study was conducted in private study rooms where each subject had their own which were protected from external time and signals.
Procedure, Instruments, and Techniques
Every single study started with three, day-and-night standard days that consisted of sixteen hours of sleeplessness and eight-hour sleep opportunity. This was planned following the typical sleeping and waking time for each participant beginning from the week before the study. The three standard days were accompanied by a desynchrony section that consisted of eighteen, twenty-hour days corresponding to fifteen days of the calendar. There were 13.33 hours of sleeplessness and a 6.67 hour sleep moment each day and the sleep episodes were planned to start four hours earlier. The outcome of this was sleeping and waking incidents taking place at all circadian stages (Silva & Duffy 2008). The light intensity of the surrounding was planned during wake episodes and the staff was not to discuss the time of day with the subjects. During the planned sleep episodes, the lights were turned off. A rectal temperature sensor was used to record body temperature whereby it was worn all through the study to aid in the evaluation of circadian stages. For all the planned sleep occurrences, the polysomnogram was documented using the standard montage. A vita port digital sleep recorder was used to acquire the polysomnogram data. A computer was used to automatically switch off the lights.
Results of the study
Results from the study show that the impacts of sleep inertia are existent in healthy older adults when they sleep at their usual intervals and performance improves as wake time escalates. The majority of the subjects were not able to remain asleep for the whole eight-hour sleep opportunity which is usual for persons in this age set (Silva & Duffy 2008). There was a substantial impact of the circadian stage on performance resulting from wakening, with the first performance when awakening in the early afternoon. When the waking period befell in the late evening and during the night, the performance was poor. In the circadian stage where there exists the most sleep inertia impact, there are significant implications for older adults. Elder adults wake at an earlier circadian stage compared to younger adults. There was also a substantial impact of the sleep stage on awakening performance, whereby the early stages of performance are greater when subjects woke up from REM sleep compared to the time they woke up from NREM phases one or two sleep. The findings showed that elder adults go through more stages of sleep inertia at their normal wake up intervals because they usually wake up at an earlier natural interval, nearer to the essential body temperature when the impacts of sleep inertia are extreme and therefore the study turned out as anticipated.
Strengths and Weaknesses
The study used an effective procedure and equipment that gave detailed data throughout the study (Silva & Duffy 2008). The participants were well assessed before the study and therefore relative results. Each subject had its study room hence the capability for the study to provide effective results. However, in some of the cases, planned tests were delayed due to technical issues. The study used a few subjects and only concentrated on healthy ones. The findings from the study maintain that older adults are more open to sleep inertia compared to younger adults.
References
Silva, E. J., & Duffy, J. F. (2008). Sleep inertia varies with circadian phase and sleep stage in
older adults. Behavioral neuroscience, 122(4), 928.
