The Effect of Memory Load on the Circadian Variation in Performance Efficiency Under a Rapidly Rotating Shift System*

Folkard, Simon; Knauth, Peter; Monk, Timothy H.

doi:10.1080/00140137608931559

Cited by 149 publications

(78 citation statements)

References 15 publications

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“…Strategy changes in relation to arousal changes have also been proposed to account for performance variations observed in laboratory studies. In the morning, when arousal was low, performance was shown to peak in those tasks involving more automatic processing, while increasing arousal across the day would favour more elaborate processing, like processing of semantic aspects from long-term memory (Baddeley et al, 1970;Folkard, 1979;Folkard et al, 1976;Folkard & Monk, 1980;Lorenzetti & Natale, 1996;Oakhill & Davies, 1989). This hypothesis was favoured by the finding of significant correlations between operators' self-rated alertness and their task performance.…”

Section: Discussionmentioning

confidence: 99%

“…A reduction in response speed during the night coincident with an increase in response accuracy, suggested a strategy change rather than a global nocturnal performance drop (Monk & Carrier, 1997). When the emphasis was on short-term memory processing, superior performance was reported in the morning, while for longterm memory tasks performance peaks were observed on the late afternoon (Baddeley, Hatter, Scott & Snashall, 1970;Folkard, Knauth, Monk, & Rutenfranz, 1976;Folkard & Monk, 1980; Oakhill & Davies, 1989).…”

Section: Introductionmentioning

confidence: 99%

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

2008

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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...

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

2008

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“…A search and mem ory (SAM) test, derived from Folkard et al (15), was give n in which the subj ects had to cancel one , three, and five target letters, respectively, in three groups of four lines of 30 letters. Thi s test was performed at the start, middle , and end of the shift .…”

Section: Methodsmentioning

confidence: 99%

Effect of bright light on tolerance to night work.

Costa

Ghirlanda²,

Minors³

et al. 1993

Scand J Work Environ Health

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female nurses engaged in a resuscitation unit and working on a fast rotating shift schedule comprising two consecutive night shifts were exposed to short periods (4 x 20 min) of bright light (2350 Ix) during their night duty to test a possible positive effect on their tolerance to night work. Two nights with normal lighting (20-380 Ix) and two nights with bright light were compared. The following positive effects of bright light upon psychophysical conditions and performance efficiency were noted: in particular, signs of better physical fitness; less tiredness and sleepiness; a more balanced sleep pattern; and higher performance efficiency (letter cancellation test). This result could not be attributed to shifts of the internal clock although the exact cause remains to be determined. In fact, hormonal excretion and body temperature did not show any effect from bright light. In addition melatonin excretion was not suppressed appreciably by the bright light used.

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“…If one or more letters was (were) missing, the "D" key was pressed for "different. " This task was adapted from the Memory and Search Tasks of Folkard, Knauth, Monk, and Rutenfranz (1976), and took approximately 2 min.…”

Section: Methods Test Instruments Performance Assessment Batterymentioning

confidence: 99%

Dynamic changes in work/rest duty cycles in a study of sleep deprivation

Babkoff

Thorne

Sing

et al. 1985

Behavior Research Methods, Instruments, & Computers

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The effects of moderate workload and 72 h of sleep deprivation were studied using a modified continuous-performance paradigm. Ten subjects were tested hourly on a number of perceptual and cognitive tasks designed to require approximately 30 min to complete, with the remainder of each hour free. As sleep deprivation continued, the average time on task increased at an accelerating rate. The rate of increase differed among tasks, with longer tasks showing greater absolute and relative increases than shorter ones. Such increases confound sleep deprivation and workload effects. In this paper, we compare the advantages and disadvantages of several experimental paradigms; describe details of the present design; and discuss methodological problems associated with separating the interactions of sleep deprivation, workload, and circadian variation with performance.

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The Effect of Memory Load on the Circadian Variation in Performance Efficiency Under a Rapidly Rotating Shift System*

Cited by 149 publications

References 15 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

Effect of bright light on tolerance to night work.

Dynamic changes in work/rest duty cycles in a study of sleep deprivation

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