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Cassie J Hilditch - One of the best experts on this subject based on the ideXlab platform.
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0175 Light Improves Alertness and Mood During the Sleep Inertia Period Following Slow Wave Sleep
Sleep, 2020Co-Authors: Cassie J Hilditch, Nathan H. Feick, Lily R Wong, N G Bathurst, Erin E. Flynn-evansAbstract:Abstract Introduction Waking from Sleep, especially slow wave Sleep (SWS), is associated with reduced alertness known as Sleep Inertia. Light improves alertness during Sleep deprivation and circadian misalignment. In this study, we assessed the efficacy of light to improve alertness and mood immediately after waking from SWS. Methods Twelve participants kept a Sleep schedule of 8.5 h for 5 nights and 5 h for one night prior to the overnight laboratory visit (confirmed by actigraphy). Participants went to bed at their scheduled habitual bedtime in the laboratory and were monitored by standard polysomnography. After at least 5 min of SWS, participants were awoken and exposed to either red ambient light (control) or blue-enriched bright light (light) for 1 h. During this time, participants completed a subjective scale of alertness (Karolinska Sleepiness Scale, KSS) and visual analogue scales (VAS) of mood at 2 min, 17 min, 32 min, and 47 min after waking. Following this Sleep Inertia measurement period, all lights were turned off and participants were allowed to return to Sleep. They were then awoken again from their subsequent SWS period and exposed to the opposite condition (control or light). A linear mixed-effects model with fixed effects of condition, time, and condition*time and a random effect of participant was used to determine the impact of light across the testing period. An average of baseline responses (pre-Sleep) was included as a covariate. Results Compared to the control condition, participants exposed to blue-enriched bright light reported feeling more alert (KSS: F1,77=4.955, p=.029; VASalert: F1,77=8.226, p=.005), more cheerful (VAScheerful: F1,77=8.615, p=.004), less depressed (VASdepressed: F1,77=4.649, p=.034), and less lethargic (VASlethargic: F1,77=5.652, p=.020). Conclusion Exposure to blue-enriched bright light immediately after waking from SWS may help to improve subjective alertness and mood. Future analyses will explore whether these findings extend to effects on cognitive performance. Support Naval Postgraduate School Grant. NASA Airspace Operations and Safety Program, System-Wide Safety Project.
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Exercising Caution Upon Waking-Can Exercise Reduce Sleep Inertia?
Frontiers in physiology, 2020Co-Authors: Katya Kovac, Cassie J Hilditch, Sally A. Ferguson, Jessica L. Paterson, Brad Aisbett, Amy C. Reynolds, Grace E. VincentAbstract:Sleep Inertia, the transitional state of reduced alertness and impaired cognitive performance upon waking, is a safety risk for on-call personnel who can be required to perform critical tasks soon after waking. Sleep Inertia countermeasures have previously been investigated, however none have successfully dissipated Sleep Inertia within the first 15 min following waking. During this time on-call personnel could already be driving, providing advice, or performing other safety-critical tasks. Exercise has not yet been investigated as a Sleep Inertia countermeasure but has the potential to stimulate the key physiological mechanisms that occur upon waking, including changes in cerebral blood flow and functional connectivity within the brain, the cortisol awakening response and increases in core body temperature. Here we examine these physiological processes and hypothesises how exercise can stimulate them, positioning exercise as an effective Sleep Inertia countermeasure. We then propose key considerations for research investigating the efficacy of exercise as a Sleep Inertia countermeasure, including the need to determine the intensity and duration of exercise required to reduce Sleep Inertia, as well as testing the effectiveness of exercise across a range of conditions in which the severity of Sleep Inertia may vary. Finally, practical considerations are identified, including the recommendation that qualitative field-based research be conducted with on-call personnel to determine the potential constraints in utilising exercise as a Sleep Inertia countermeasure in real-world scenarios.
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Sleep Inertia: current insights
Nature and science of sleep, 2019Co-Authors: Cassie J Hilditch, Andrew W. MchillAbstract:Sleep Inertia, or the grogginess felt upon awakening, is associated with significant cognitive performance decrements that dissipate as time awake increases. This impairment in cognitive performance has been observed in both tightly controlled in-laboratory studies and in real-world scenarios. Further, these decrements in performance are exaggerated by prior Sleep loss and the time of day in which a person awakens. This review will examine current insights into the causes of Sleep Inertia, factors that may positively or negatively influence the degree of Sleep Inertia, the consequences of Sleep Inertia both in the laboratory and in real-world settings, and lastly discuss potential countermeasures to lessen the impact of Sleep Inertia.
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Sleep Inertia associated with a 10 min nap before the commute home following a night shift a laboratory simulation study
Accident Analysis & Prevention, 2017Co-Authors: Cassie J Hilditch, Hans P. A. Van Dongen, Jillian Dorrian, Stephanie Centofanti, Siobhan BanksAbstract:Night shift workers are at risk of road accidents due to Sleepiness on the commute home. A brief nap at the end of the night shift, before the commute, may serve as a Sleepiness countermeasure. However, there is potential for Sleep Inertia, i.e. transient impairment immediately after awakening from the nap. We investigated whether Sleep Inertia diminishes the effectiveness of napping as a Sleepiness countermeasure before a simulated commute after a simulated night shift. N=21 healthy subjects (aged 21-35 y; 12 females) participated in a 3-day laboratory study. After a baseline night, subjects were kept awake for 27h for a simulated night shift. They were randomised to either receive a 10-min nap ending at 04:00 plus a 10-min pre-drive nap ending at 07:10 (10-NAP) or total Sleep deprivation (NO-NAP). A 40-min York highway driving task was performed at 07:15 to simulate the commute. A 3-min psychomotor vigilance test (PVT-B) and the Samn-Perelli Fatigue Scale (SP-Fatigue) were administered at 06:30 (pre-nap), 07:12 (post-nap), and 07:55 (post-drive). In the 10-NAP condition, total pre-drive nap Sleep time was 9.1±1.2min (mean±SD), with 1.3±1.9min spent in slow wave Sleep, as determined polysomnographically. There was no difference between conditions in PVT-B performance at 06:30 (before the nap). In the 10-NAP condition, PVT-B performance was worse after the nap (07:12) compared to before the nap (06:30); no change across time was found in the NO-NAP condition. There was no significant difference between conditions in PVT-B performance after the drive. SP-Fatigue and driving performance did not differ significantly between conditions. In conclusion, the pre-drive nap showed objective, but not subjective, evidence of Sleep Inertia immediately after awakening. The 10-min nap did not affect driving performance during the simulated commute home, and was not effective as a Sleepiness countermeasure.
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A review of short naps and Sleep Inertia: do naps of 30 min or less really avoid Sleep Inertia and slow-wave Sleep?
Sleep medicine, 2017Co-Authors: Cassie J Hilditch, Jillian Dorrian, Siobhan BanksAbstract:Abstract Objectives Napping is a widely used countermeasure to Sleepiness and impaired performance caused by Sleep loss and circadian pressure. Sleep Inertia, the period of grogginess and impaired performance experienced after waking, is a potential side effect of napping. Many industry publications recommend naps of 30 min or less to avoid this side effect. However, the evidence to support this advice is yet to be thoroughly reviewed. Methods Electronic databases were searched, and defined criteria were applied to select articles for review. The review covers literature on naps of 30 min or less regarding (a) Sleep Inertia, (b) slow-wave Sleep (SWS) and (c) the relationship between Sleep Inertia and SWS. Results The review found that although the literature on short afternoon naps is relatively comprehensive, there are very few studies on naps of 30 min or less at night. Studies have mixed results regarding the onset of SWS and the duration and severity of Sleep Inertia following short naps, making guidelines regarding their use unclear. The varying results are likely due to differing Sleep/wake profiles before the nap of interest and the time of the day at waking. Conclusions The review highlights the need to have more detailed guidelines about the implementation of short naps according to the time of the day and prior Sleep/wake history. Without this context, such a recommendation is potentially misleading. Further research is required to better understand the interactions between these factors, especially at night, and to provide more specific recommendations.
Derk-jan Dijk - One of the best experts on this subject based on the ideXlab platform.
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Morning Sleep Inertia in alertness and performance: effect of cognitive domain and white light conditions.
PloS one, 2013Co-Authors: Nayantara Santhi, John A. Groeger, Luc J. M. Schlangen, Simon Archer, Marina C. Gimenez, Derk-jan DijkAbstract:The transition from Sleep to wakefulness entails a temporary period of reduced alertness and impaired performance known as Sleep Inertia. The extent to which its severity varies with task and cognitive processes remains unclear. We examined Sleep Inertia in alertness, attention, working memory and cognitive throughput with the Karolinska Sleepiness Scale (KSS), the Psychomotor Vigilance Task (PVT), n-back and add tasks, respectively. The tasks were administered 2 hours before bedtime and at regular intervals for four hours, starting immediately after awakening in the morning, in eleven participants, in a four-way cross-over laboratory design. We also investigated whether exposure to Blue-Enhanced or Bright Blue-Enhanced white light would reduce Sleep Inertia. Alertness and all cognitive processes were impaired immediately upon awakening (p
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morning Sleep Inertia in alertness and performance effect of cognitive domain and white light conditions
PLOS ONE, 2013Co-Authors: Nayantara Santhi, John A. Groeger, Luc J. M. Schlangen, Simon Archer, Marina C. Gimenez, Derk-jan DijkAbstract:The transition from Sleep to wakefulness entails a temporary period of reduced alertness and impaired performance known as Sleep Inertia. The extent to which its severity varies with task and cognitive processes remains unclear. We examined Sleep Inertia in alertness, attention, working memory and cognitive throughput with the Karolinska Sleepiness Scale (KSS), the Psychomotor Vigilance Task (PVT), n-back and add tasks, respectively. The tasks were administered 2 hours before bedtime and at regular intervals for four hours, starting immediately after awakening in the morning, in eleven participants, in a four-way cross-over laboratory design. We also investigated whether exposure to Blue-Enhanced or Bright Blue-Enhanced white light would reduce Sleep Inertia. Alertness and all cognitive processes were impaired immediately upon awakening (p<0.01). However, alertness and sustained attention were more affected than cognitive throughput and working memory. Moreover, speed was more affected than accuracy of responses. The light conditions had no differential effect on performance except in the 3-back task (p<0.01), where response times (RT) at the end of four hours in the two Blue-Enhanced white light conditions were faster (200 ms) than at wake time. We conclude that the effect of Sleep Inertia varies with cognitive domain and that it’s spectral/intensity response to light is different from that of Sleepiness. That is, just increasing blue-wavelength in light may not be sufficient to reduce Sleep Inertia. These findings have implications for critical professions like medicine, law-enforcement etc., in which, personnel routinely wake up from night-time Sleep to respond to emergency situations.
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Effects of Sleep Inertia after daytime naps vary with executive load and time of day.
Behavioral neuroscience, 2011Co-Authors: John A. Groeger, Christopher G Burns, Derk-jan DijkAbstract:The effects of executive load on working memory performance during Sleep Inertia after morning or afternoon naps were assessed using a mixed design with nap/wake as a between-subjects factor and morning/afternoon condition as a within-subject factor. Thirty-two healthy adults (mean 22.5 ± 3.0 years) attended two laboratory sessions after a night of restricted Sleep (6 hrs), and at first visit, were randomly assigned to the Nap or Wake group. Working memory (n-back) and subjective workload were assessed approximately 5 and 25 minutes after 90-minute morning and afternoon nap opportunities and at the corresponding times in the Wake condition. Actigraphically assessed nocturnal Sleep duration, subjective Sleepiness, and psychomotor vigilance performance before daytime assessments did not vary across conditions. Afternoon naps showed shorter EEG assessed Sleep latencies, longer Sleep duration, and more Slow Wave Sleep than morning naps. Working memory performance deteriorated, and subjective mental workload increased at higher executive loadings. After afternoon naps, participants performed less well on more executive-function intensive working memory tasks (i.e., 3-back), but waking and napping participants performed equally well on simpler tasks. After some 30 minutes of cognitive activity, there were no longer performance differences between the waking and napping groups. Subjective Task Difficulty and Mental Effort requirements were less affected by Sleep Inertia and dissociated from objective measures when participants had napped in the afternoon. We conclude that executive functions take longer to return to asymptotic performance after Sleep than does performance of simpler tasks which are less reliant on executive functions.
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time course of Sleep Inertia dissipation in human performance and alertness
Journal of Sleep Research, 1999Co-Authors: Megan E Jewett, Derk-jan Dijk, James K Wyatt, Ritzde A Cecco, Sat Bir S. Khalsa, Charles A CzeislerAbstract:Alertness and performance on a wide variety of tasks are impaired immediately upon waking from Sleep due to Sleep Inertia, which has been found to dissipate in an asymptotic manner following waketime. It has been suggested that behavioural or environmental factors, as well as Sleep stage at awakening, may affect the severity of Sleep Inertia. In order to determine the time course of Sleep Inertia dissipation under normal entrained conditions, subjective alertness and cognitive throughput were measured during the first 4 h after habitual waketime from a full 8-h Sleep episode on 3 consecutive days. We investigated whether this time course was affected by either Sleep stage at awakening or behavioural/environmental factors. Sleep Inertia dissipated in an asymptotic manner and took 2-4 h to near the asymptote. Saturating exponential functions fitted the Sleep Inertia data well, with time constants of 0.67 h for subjective alertness and 1.17 h for cognitive performance. Most awakenings occurred out of stage rapid eye movement (REM), 2 or 1 Sleep, and no effect of Sleep stage at awakening on either the severity of Sleep Inertia or the time course of its dissipation could be detected. Subjective alertness and cognitive throughput were significantly impaired upon awakening regardless of whether subjects got out of bed, ate breakfast, showered and were exposed to ordinary indoor room light (approximately 150 lux) or whether subjects participated in a constant routine (CR) protocol in which they remained in bed, ate small hourly snacks and were exposed to very dim light (10-15 lux). These findings allow for the refinement of models of alertness and performance, and have important implications for the scheduling of work immediately upon awakening in many occupational settings.
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Time course of Sleep Inertia after nighttime and daytime Sleep episodes
Archives italiennes de biologie, 1995Co-Authors: Peter Achermann, Derk-jan Dijk, Esther Werth, Alexander A. BorbélyAbstract:Sleep Inertia refers to the period of reduced vigilance following upon awakening from Sleep. To investigate the time course of Sleep Inertia, self-ratings of alertness and reaction time in a memory task were repeatedly assessed after nighttime and daytime Sleep episodes in healthy young men. Alertness gradually increased and reaction time gradually decreased within the first hour after awakening. Their time course could be described by exponential functions with time constants of 0.45 h and 0.3 h, respectively. The data demonstrate that Sleep Inertia is a robust, quantifiable process that can be incorporated in models of Sleep and vigilance.
Grace E. Vincent - One of the best experts on this subject based on the ideXlab platform.
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Can an increase in noradrenaline induced by brief exercise counteract Sleep Inertia
Chronobiology international, 2020Co-Authors: Katya Kovac, Jessica L. Paterson, Brad Aisbett, Amy C. Reynolds, Grace E. Vincent, Sally A. FergusonAbstract:Emergency responders often credit ‘adrenaline’ (i.e. sympathetic activity) as the reason they respond quickly upon waking, unimpaired by Sleep Inertia. Movement upon waking may promote sympathetic ...
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Safety implications of fatigue and Sleep Inertia for emergency services personnel.
Sleep medicine reviews, 2020Co-Authors: Drew Dawson, Sally A. Ferguson, Grace E. VincentAbstract:Summary Emergency services present a unique operational environment for the management of fatigue and Sleep Inertia. Communities request and often expect the provision of emergency services on a 24/7/365 basis. This can result in highly variable workloads and/or significant need for on-demand or on-call working time arrangements. In turn, the management of fatigue-related risk requires a different approach than in other more predictable shift working sectors (e.g. mining and manufacturing). The aim of this review is to provide a comprehensive overview of fatigue risk management that is accessible to regulators, policy makers and organisations in the emergency services sector. The review outlines the unique fatigue challenges in the emergency services sector, examines the current scientific and policy consensus around managing fatigue and Sleep Inertia, and finally discusses strategies that emergency services organisations can use to minimise the risks associated with fatigue and Sleep Inertia.
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Exercising Caution Upon Waking-Can Exercise Reduce Sleep Inertia?
Frontiers in physiology, 2020Co-Authors: Katya Kovac, Cassie J Hilditch, Sally A. Ferguson, Jessica L. Paterson, Brad Aisbett, Amy C. Reynolds, Grace E. VincentAbstract:Sleep Inertia, the transitional state of reduced alertness and impaired cognitive performance upon waking, is a safety risk for on-call personnel who can be required to perform critical tasks soon after waking. Sleep Inertia countermeasures have previously been investigated, however none have successfully dissipated Sleep Inertia within the first 15 min following waking. During this time on-call personnel could already be driving, providing advice, or performing other safety-critical tasks. Exercise has not yet been investigated as a Sleep Inertia countermeasure but has the potential to stimulate the key physiological mechanisms that occur upon waking, including changes in cerebral blood flow and functional connectivity within the brain, the cortisol awakening response and increases in core body temperature. Here we examine these physiological processes and hypothesises how exercise can stimulate them, positioning exercise as an effective Sleep Inertia countermeasure. We then propose key considerations for research investigating the efficacy of exercise as a Sleep Inertia countermeasure, including the need to determine the intensity and duration of exercise required to reduce Sleep Inertia, as well as testing the effectiveness of exercise across a range of conditions in which the severity of Sleep Inertia may vary. Finally, practical considerations are identified, including the recommendation that qualitative field-based research be conducted with on-call personnel to determine the potential constraints in utilising exercise as a Sleep Inertia countermeasure in real-world scenarios.
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Exercise before bed does not impact Sleep Inertia in young healthy males.
Journal of sleep research, 2019Co-Authors: Grace E. Vincent, Katya Kovac, Charli Sargent, Gregory D. Roach, Dean J Miller, Aaron T. Scanlan, Lauren B Waggoner, Michele LastellaAbstract:Sleep Inertia is the transitional state marked by impaired cognitive performance and reduced vigilance upon waking. Exercising before bed may increase the amount of slow-wave Sleep within the Sleep period, which has previously been associated with increased Sleep Inertia. Healthy males (n = 12) spent 3 nights in a Sleep laboratory (1-night washout period between each night) and completed one of the three conditions on each visit - no exercise, aerobic exercise (30 min cycling at 75% heart rate), and resistance exercise (six resistance exercises, three sets of 10 repetitions). The exercise conditions were completed 90 min prior to bed. Sleep was measured using polysomnography. Upon waking, participants completed five test batteries every 15 min, including the Karolinska Sleepiness Scale, a Psychomotor Vigilance Task, and the Spatial Configuration Task. Two separate linear mixed-effects models were used to assess: (a) the impact of condition; and (b) the amount of slow-wave Sleep, on Sleep Inertia. There were no significant differences in Sleep Inertia between conditions, likely as a result of the similar Sleep amount, Sleep structure and time of awakening between conditions. The amount of slow-wave Sleep impacted fastest 10% reciprocal reaction time on the Psychomotor Vigilance Task only, whereby more slow-wave Sleep improved performance; however, the magnitude of this relationship was small. Results from this study suggest that exercise performed 90 min before bed does not negatively impact on Sleep Inertia. Future studies should investigate the impact of exercise intensity, duration and timing on Sleep and subsequent Sleep Inertia.
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The impact of anticipating a stressful task on Sleep Inertia when on-call
Applied ergonomics, 2019Co-Authors: Katya Kovac, Brad Aisbett, Grace E. Vincent, Sarah M. Jay, Madeline Sprajcer, Leon Lack, Sally A. FergusonAbstract:Abstract Sleep Inertia, the state of reduced alertness upon waking, can negatively impact on-call workers. Anticipation of a stressful task on Sleep Inertia, while on-call was investigated. Young, healthy males (n = 23) spent an adaptation, control and two counterbalanced on-call nights in the laboratory. When on-call, participants were told they would be woken to a high or low stress task. Participants were not woken during the night, instead were given a 2300-0700 Sleep opportunity. Participants slept ∼7.5-h in all conditions. Upon waking, Sleep Inertia was quantified using the Karolinska Sleepiness Scale and Psychomotor Vigilance and Spatial Configuration Tasks, administered at 15-min intervals. Compared to control, participants felt Sleepier post waking when on-call and Sleepiest in the low stress compared to the high stress condition (p
Siobhan Banks - One of the best experts on this subject based on the ideXlab platform.
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Sleep Inertia associated with a 10 min nap before the commute home following a night shift a laboratory simulation study
Accident Analysis & Prevention, 2017Co-Authors: Cassie J Hilditch, Hans P. A. Van Dongen, Jillian Dorrian, Stephanie Centofanti, Siobhan BanksAbstract:Night shift workers are at risk of road accidents due to Sleepiness on the commute home. A brief nap at the end of the night shift, before the commute, may serve as a Sleepiness countermeasure. However, there is potential for Sleep Inertia, i.e. transient impairment immediately after awakening from the nap. We investigated whether Sleep Inertia diminishes the effectiveness of napping as a Sleepiness countermeasure before a simulated commute after a simulated night shift. N=21 healthy subjects (aged 21-35 y; 12 females) participated in a 3-day laboratory study. After a baseline night, subjects were kept awake for 27h for a simulated night shift. They were randomised to either receive a 10-min nap ending at 04:00 plus a 10-min pre-drive nap ending at 07:10 (10-NAP) or total Sleep deprivation (NO-NAP). A 40-min York highway driving task was performed at 07:15 to simulate the commute. A 3-min psychomotor vigilance test (PVT-B) and the Samn-Perelli Fatigue Scale (SP-Fatigue) were administered at 06:30 (pre-nap), 07:12 (post-nap), and 07:55 (post-drive). In the 10-NAP condition, total pre-drive nap Sleep time was 9.1±1.2min (mean±SD), with 1.3±1.9min spent in slow wave Sleep, as determined polysomnographically. There was no difference between conditions in PVT-B performance at 06:30 (before the nap). In the 10-NAP condition, PVT-B performance was worse after the nap (07:12) compared to before the nap (06:30); no change across time was found in the NO-NAP condition. There was no significant difference between conditions in PVT-B performance after the drive. SP-Fatigue and driving performance did not differ significantly between conditions. In conclusion, the pre-drive nap showed objective, but not subjective, evidence of Sleep Inertia immediately after awakening. The 10-min nap did not affect driving performance during the simulated commute home, and was not effective as a Sleepiness countermeasure.
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A review of short naps and Sleep Inertia: do naps of 30 min or less really avoid Sleep Inertia and slow-wave Sleep?
Sleep medicine, 2017Co-Authors: Cassie J Hilditch, Jillian Dorrian, Siobhan BanksAbstract:Abstract Objectives Napping is a widely used countermeasure to Sleepiness and impaired performance caused by Sleep loss and circadian pressure. Sleep Inertia, the period of grogginess and impaired performance experienced after waking, is a potential side effect of napping. Many industry publications recommend naps of 30 min or less to avoid this side effect. However, the evidence to support this advice is yet to be thoroughly reviewed. Methods Electronic databases were searched, and defined criteria were applied to select articles for review. The review covers literature on naps of 30 min or less regarding (a) Sleep Inertia, (b) slow-wave Sleep (SWS) and (c) the relationship between Sleep Inertia and SWS. Results The review found that although the literature on short afternoon naps is relatively comprehensive, there are very few studies on naps of 30 min or less at night. Studies have mixed results regarding the onset of SWS and the duration and severity of Sleep Inertia following short naps, making guidelines regarding their use unclear. The varying results are likely due to differing Sleep/wake profiles before the nap of interest and the time of the day at waking. Conclusions The review highlights the need to have more detailed guidelines about the implementation of short naps according to the time of the day and prior Sleep/wake history. Without this context, such a recommendation is potentially misleading. Further research is required to better understand the interactions between these factors, especially at night, and to provide more specific recommendations.
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Time to wake up: reactive countermeasures to Sleep Inertia
Industrial health, 2016Co-Authors: Cassie J Hilditch, Jillian Dorrian, Siobhan BanksAbstract:Sleep Inertia is the period of impaired performance and grogginess experienced after waking. This period of impairment is of concern to workers who are on-call, or nap during work hours, and need to perform safety-critical tasks soon after waking. While several studies have investigated the best Sleep timing and length to minimise Sleep Inertia effects, few have focused on countermeasures -especially those that can be implemented after waking (i.e. reactive countermeasures). This structured review summarises current literature on reactive countermeasures to Sleep Inertia such as caffeine, light, and temperature and discusses evidence for the effectiveness and operational viability of each approach. Current literature does not provide a convincing evidence-base for a reactive countermeasure. Caffeine is perhaps the best option, although it is most effective when administered prior to Sleep and is therefore not strictly reactive. Investigations into light and temperature have found promising results for improving subjective alertness; further research is needed to determine whether these countermeasures can also attenuate performance impairment. Future research in this area would benefit from study design features highlighted in this review. In the meantime, it is recommended that proactive Sleep Inertia countermeasures are used, and that safety-critical tasks are avoided immediately after waking.
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Sleep Inertia during a simulated 6-h on/6-h off fixed split duty schedule.
Chronobiology international, 2016Co-Authors: Cassie J Hilditch, Hans P. A. Van Dongen, Jillian Dorrian, Michelle A. Short, Stephanie Centofanti, Mark Kohler, Siobhan BanksAbstract:Sleep Inertia is a safety concern for shift workers returning to work soon after waking up. Split duty schedules offer an alternative to longer shift periods, but introduce additional wake-ups and may therefore increase risk of Sleep Inertia. This study investigated Sleep Inertia across a split duty schedule. Sixteen participants (age range 21-36 years; 10 females) participated in a 9-day laboratory study with two baseline nights (10 h time in bed, [TIB]), four 24-h periods of a 6-h on/6-h off split duty schedule (5-h TIB in off period; 10-h TIB per 24 h) and two recovery nights. Two complementary rosters were evaluated, with the timing of Sleep and wake alternating between the two rosters (2 am/2 pm wake-up roster versus 8 am/8 pm wake-up roster). At 2, 17, 32 and 47 min after scheduled awakening, participants completed an 8-min Inertia test bout, which included a 3-min psychomotor vigilance test (PVT-B), a 3-min Digit-Symbol Substitution Task (DSST), the Karolinska Sleepiness Scale (KSS), and the Samn-Perelli Fatigue Scale (SP-Fatigue). Further testing occurred every 2 h during scheduled wakefulness. Performance was consistently degraded and subjective Sleepiness/fatigue was consistently increased during the Inertia testing period as compared to other testing times. Morning wake-ups (2 am and 8 am) were associated with higher levels of Sleep Inertia than later wake-ups (2 pm and 8 pm). These results suggest that split duty workers should recognise the potential for Sleep Inertia after waking, especially during the morning hours.
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A 30-Minute, but Not a 10-Minute Nighttime Nap is Associated with Sleep Inertia.
Sleep, 2016Co-Authors: Cassie J Hilditch, Jillian Dorrian, Stephanie Centofanti, Siobhan BanksAbstract:STUDY OBJECTIVES: To assess Sleep Inertia following 10-min and 30-min naps during a simulated night shift. METHODS: Thirty-one (31) healthy adults (aged 21-35 y; 18 females) participated in a 3-day laboratory study that included one baseline (BL) Sleep (22:00-07:00) and one experimental night involving randomization to either: total Sleep deprivation (NO-NAP), a 10-min nap (10-NAP) or a 30-min nap (30-NAP). Nap opportunities ended at 04:00. A 3-min psychomotor vigilance task (PVT-B), digit-symbol substitution task (DSST), fatigue scale, Sleepiness scale, and self-rated performance scale were undertaken prenap (03:00) and at 2, 17, 32, and 47 min postnap. RESULTS: The 30-NAP (14.7 ± 5.7 min) had more slow wave Sleep than the 10-NAP (0.8 ± 1.5 min; P CONCLUSIONS: This study is the first to show that a 10-min - but not a 30-min - nighttime nap had minimal Sleep Inertia and helped to mitigate short-term performance impairment during a simulated night shift. Self-rated performance did not reflect objective performance following a nap. Language: en
Sally A. Ferguson - One of the best experts on this subject based on the ideXlab platform.
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Can an increase in noradrenaline induced by brief exercise counteract Sleep Inertia
Chronobiology international, 2020Co-Authors: Katya Kovac, Jessica L. Paterson, Brad Aisbett, Amy C. Reynolds, Grace E. Vincent, Sally A. FergusonAbstract:Emergency responders often credit ‘adrenaline’ (i.e. sympathetic activity) as the reason they respond quickly upon waking, unimpaired by Sleep Inertia. Movement upon waking may promote sympathetic ...
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Safety implications of fatigue and Sleep Inertia for emergency services personnel.
Sleep medicine reviews, 2020Co-Authors: Drew Dawson, Sally A. Ferguson, Grace E. VincentAbstract:Summary Emergency services present a unique operational environment for the management of fatigue and Sleep Inertia. Communities request and often expect the provision of emergency services on a 24/7/365 basis. This can result in highly variable workloads and/or significant need for on-demand or on-call working time arrangements. In turn, the management of fatigue-related risk requires a different approach than in other more predictable shift working sectors (e.g. mining and manufacturing). The aim of this review is to provide a comprehensive overview of fatigue risk management that is accessible to regulators, policy makers and organisations in the emergency services sector. The review outlines the unique fatigue challenges in the emergency services sector, examines the current scientific and policy consensus around managing fatigue and Sleep Inertia, and finally discusses strategies that emergency services organisations can use to minimise the risks associated with fatigue and Sleep Inertia.
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Exercising Caution Upon Waking-Can Exercise Reduce Sleep Inertia?
Frontiers in physiology, 2020Co-Authors: Katya Kovac, Cassie J Hilditch, Sally A. Ferguson, Jessica L. Paterson, Brad Aisbett, Amy C. Reynolds, Grace E. VincentAbstract:Sleep Inertia, the transitional state of reduced alertness and impaired cognitive performance upon waking, is a safety risk for on-call personnel who can be required to perform critical tasks soon after waking. Sleep Inertia countermeasures have previously been investigated, however none have successfully dissipated Sleep Inertia within the first 15 min following waking. During this time on-call personnel could already be driving, providing advice, or performing other safety-critical tasks. Exercise has not yet been investigated as a Sleep Inertia countermeasure but has the potential to stimulate the key physiological mechanisms that occur upon waking, including changes in cerebral blood flow and functional connectivity within the brain, the cortisol awakening response and increases in core body temperature. Here we examine these physiological processes and hypothesises how exercise can stimulate them, positioning exercise as an effective Sleep Inertia countermeasure. We then propose key considerations for research investigating the efficacy of exercise as a Sleep Inertia countermeasure, including the need to determine the intensity and duration of exercise required to reduce Sleep Inertia, as well as testing the effectiveness of exercise across a range of conditions in which the severity of Sleep Inertia may vary. Finally, practical considerations are identified, including the recommendation that qualitative field-based research be conducted with on-call personnel to determine the potential constraints in utilising exercise as a Sleep Inertia countermeasure in real-world scenarios.
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The impact of anticipating a stressful task on Sleep Inertia when on-call
Applied ergonomics, 2019Co-Authors: Katya Kovac, Brad Aisbett, Grace E. Vincent, Sarah M. Jay, Madeline Sprajcer, Leon Lack, Sally A. FergusonAbstract:Abstract Sleep Inertia, the state of reduced alertness upon waking, can negatively impact on-call workers. Anticipation of a stressful task on Sleep Inertia, while on-call was investigated. Young, healthy males (n = 23) spent an adaptation, control and two counterbalanced on-call nights in the laboratory. When on-call, participants were told they would be woken to a high or low stress task. Participants were not woken during the night, instead were given a 2300-0700 Sleep opportunity. Participants slept ∼7.5-h in all conditions. Upon waking, Sleep Inertia was quantified using the Karolinska Sleepiness Scale and Psychomotor Vigilance and Spatial Configuration Tasks, administered at 15-min intervals. Compared to control, participants felt Sleepier post waking when on-call and Sleepiest in the low stress compared to the high stress condition (p
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Can stress act as a Sleep Inertia countermeasure when on-call?
Biological Rhythm Research, 2018Co-Authors: Sarah M. Jay, Sally A. Ferguson, Brad Aisbett, Donna M. Carley, Jessica L. PatersonAbstract:The nature of on-call work is such that workers can be called and required to respond immediately after being woken. However, due to Sleep Inertia, impaired performance immediately upon waking is t...
