Experimental Studies of Shift-Work I: A Comparison of ‘ Rotating ’ and ‘ Stabilized ’ 4-hour Shift Systems

Colquhoun, W. P.; Blake, Matthew; Edwards, R. S.

doi:10.1080/00140136808930993

Cited by 127 publications

(41 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the one hand, task performance decrements in early morning hours have been observed for reaction time. This finding is also in agreement with a number of studies performed under controlled conditions in the laboratory (Monk et al, 1985;Monk & Carrier, 1997;Casagrande et al, 1997;Heuer et al, 1998;Owens et al, 2000;Gennaro et al, 2001;Wright et al, 2002), in simulated shift-work conditions (Fröberg et al, 1975;Colquhoun et al, 1968;Johnson et al, 1992), and in real shift-work settings (Tilley et al, 1982;Hossain et al, 2004). On the other hand, in the more demanding cognitive tasks, time-of-day effects interacted with the task components that were manipulated.…”

Section: Discussionsupporting

confidence: 80%

“…Systematic performance measures in relation to different simulated shift systems further confirmed a sharp performance drop in the early morning hours (Colquhoun, 1969). This was observed in most tasks that require sustained attention, such as reaction time performance or throughput in cognitive tasks (Fröberg, 1975;Colquhoun, 1968;Johnson, 1992). At the same time, physiological, and subjective arousal were reported to strongly decrease (Akerstedt & Gillberg, 1990).…”

Section: Introductionmentioning

confidence: 79%

See 1 more Smart Citation

Investigation of task performance variations according to task requirements and alertness across the 24-h day in shift workers

2008

View full text Add to dashboard Cite

The study investigated time-of-day effects on task performance in shift-workers in different tasks (reaction-time, discrimination, probe recognition, free recall), by varying task-specific features. On each of six recordings, each programmed on a different day and in a randomized order, operators rated alertness and performed different tasks. Self-rated alertness varied according to a typical diurnal trend.Time of day also affected reaction time (slower responses at 03:00), discrimination performance (lower accuracy at 03:00 in the most difficult condition), and recall (superior recall at 07:00 and 11:00 following deeper processing at encoding). The data demonstrated time-of-day effects on cognitive processes also involved in many real-job activities, despite the lack of control for a number of exogenous factors known to interfere with performance in work settings. Since in the cognitively more loaded tasks, time-of-day effects depended on task conditions, the findings are of operational concern in shift-work situations involving differential task requirements.Keywords: Shift-workers, Alertness, Reaction time, Non-verbal Discrimination, Memory TasksPage 2 of 68 URL: http://mc.manuscriptcentral.com/terg E-mail: ergonomics@tandf.co.uk Ergonomics 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 Statement of relevanceIn a real-job setting, performance variations were observed according to time-ofday and task-requirements in a set of cognitively more or less demanding tasks.Task-specific research across the 24-h day enables a better understanding of operators' tasks and the development of supporting technology. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 IntroductionOver the last few decades, a number of studies showed how performance measures are affected by sleep drive (homeostatic influence) and circadian phase.The demonstration of an interaction of circadian phase and time awake in the regulation of performance came from laboratory studies under controlled conditions and/or manipulation of the sleep/wake cycle (for a review, Akerstedt, 2007). Several theoretical models conceptualized this interaction by proposing an optimal position and duration for sleep, with any deviation impairing performance and alertness (Folkard & Akerstedt, 1992;Achermann & Borbély, 1994; Van Dongen, Maislin, Mullington, & Dinges, 2003). Systematic performance measures in relation to different simulated shift systems further confirmed a sharp performance drop in the early morning hours (Colquhoun, 1969). This was observed in most tasks that require sustained attention, such as reaction time performance or throughput in cognitive tasks (Fröberg, 1975;Colquhoun, 1968; Johnson, 19...

show abstract

Section: Discussionsupporting

confidence: 80%

Section: Introductionmentioning

confidence: 79%

Investigation of task performance variations according to task requirements and alertness across the 24-h day in shift workers

2008

View full text Add to dashboard Cite

show abstract

“…This conclusion aligns with previous research showing that rotating watch schedules inevitably produce fragmented sleep and disrupt physiological rhythms (Colquhoun et al 1968;Colquhoun 1985). Watchstanding schedules that take human physiology into account may lead to better performance in the operational environment (Miller 2006).…”

Section: Discussionsupporting

confidence: 78%

“…Watchstanding schedules that take human physiology into account may lead to better performance in the operational environment (Miller 2006). For example, shift schedules leading to circadian-aligned 24-h day and allowing watchstanders to sleep at the same time every day are more tolerable from a circadian rhythm perspective (Colquhoun et al 1968;Colquhoun 1985). Lastly, we should emphasise the need to educate crewmembers on healthy sleep habits.…”

Section: Discussionmentioning

confidence: 99%

“…Since maritime processes use a system of shiftwork to enable continuous operations, it is not surprising that optimising shiftwork practices is a global concern for navies in general and the United States Navy (USN) in particular. Documented in a series of studies conducted at the Naval Postgraduate School over the last two decades, USN sailors are habitual shiftworkers, regularly working shifts that result in circadian misalignment (Colquhoun, Blake, and Edwards 1968). Instead of a 24-h day with opportunities to sleep about the same time each day, their work schedules result in an 18-or 20-h day that continuously cycles without weekends or time off for recovery.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department

Shattuck

Matsangas

2015

Ergonomics

View full text Add to dashboard Cite

We assessed sleep patterns, psychomotor vigilance performance, work demands and mood of 77 crewmembers of USS NIMITZ (CVN-68) on the rotating 5-h on/10-h off (5/10) watchstanding schedule. Within the 3-day cycle of the 5/10, sleep occurred at distinctly different times each day. On two of these days, sailors typically received only brief, 4-h sleep episodes followed by periods of sustained wakefulness (approximately 22 and 20 h). Crewmembers received approximately seven hours of sleep daily, but reported excessive fatigue and dissatisfaction with their schedule. Crewmembers' mood worsened significantly over the course of the underway phase. Psychomotor vigilance performance (reaction times, lapses) was significantly degraded compared to performance when working circadian-aligned schedules. Overall, standing watch on the 5/10 schedule, combined with other work duties, resulted in poor sleep hygiene. Crewmembers on the 5/10 experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep. Practitioner summary:We assessed crewmembers' sleep patterns, psychomotor vigilance performance and work demands when working a rotating 5-h on/10-h off (5/10) watchstanding schedule. The 5/10, combined with other work duties, resulted in poor sleep hygiene. Crewmembers experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep.

show abstract

Acute effects of 50 Hz, 100 μT magnetic field exposure on visual duration discrimination at two different times of the day

Kazantzis

Podd

Whittington

1998

Bioelectromagnetics

View full text Add to dashboard Cite

A two‐alternative, forced‐choice visual duration discrimination task was used to examine the effect of an intermittent, 50 Hz, 100 μT magnetic field on accuracy at two different times of the day. A total of 59 female and 40 male subjects with an age range of 18 to 46 years were studied under both field‐exposed and sham‐exposed conditions. The subject's task was to decide which of two sequentially presented light flashes had the longer duration, percentage correct being the measure of performance. The data were gathered under double‐blind conditions with sham and real exposure counterbalanced. Exposure to the magnetic field produced a small improvement in accuracy but only at the most difficult level of the task, with female subjects showing a larger improvement than males. The time of day at which the study was run had no effect on performance. Despite the relatively large number of subjects used and a relaxed alpha level (P = .3), the statistical power of the test to detect the observed effect was still only 0.71. Bioelectromagnetics 19:310–317, 1998. © 1998 Wiley‐Liss, Inc.

show abstract

Experimental Studies of Shift-Work I: A Comparison of ‘ Rotating ’ and ‘ Stabilized ’ 4-hour Shift Systems

Cited by 127 publications

References 12 publications

Investigation of task performance variations according to task requirements and alertness across the 24-h day in shift workers

Investigation of task performance variations according to task requirements and alertness across the 24-h day in shift workers

Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department

Acute effects of 50 Hz, 100 μT magnetic field exposure on visual duration discrimination at two different times of the day

Contact Info

Product

Resources

About