Diurnal Variation in Mood and Performance in a Time-Isolated Environment

Abstract

In order to document circadian rhythmicity in various psychological functions under the chronobiologically 'pure' condition of temporal isolation, a battery of mood and performance tests were administered about 6 times per day to a heterogeneous group of 18 subjects (ages 19-81, 5 female). Each subject spent about 5 days in temporal isolation, entrained to a routine equivalent to his/her own habitual sleep/wake cycle. Average time of day functions were obtained for the mood and performance variables, and compared to rectal temperature data subjected to exactly the same statistical analysis. Significant time of day effects were found in the mood variables of alertness, sleepiness, weariness, effort required, happiness and well-being. Times of 'best' mood were different from the time of peak temperature. Moreover, the minima of sleepiness, weariness and effort occurred earlier in the day than the maximum of alertness. Significant time of day effects were also found in the speed with which search and dexterity tasks were completed. Only the dexterity tasks showed a complete parallelism with the temperature rhythm.

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

“…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.…”

“…This interpretation is in agreement with the results obtained by more systematic investigations of performance variations in controlled laboratory studies. In perceptual-motor tasks, such as simple reaction time tasks restricted to immediate throughput of information, performance was usually shown to peak in the evening (Monk, Fookson, Moline, & Pollak, 1985;Monk & Carrier, 1997;Casagrande, Violani, Curcio, & Bertini, 1997;Heuer, Spijkers, Kiesswetter, & Schmidtke, 1998;Owens, Macdonald, Tucker, Sytnik, Totterdell, & et al, 2000;Gennaro, Ferrara, Curcio, & Bertini, 2001;Wright, Hull, & Czeisler, 2002). 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).…”

Recall Performance in Air Traffic Controllers Across the 24-hr Day: Influence of Alertness and Task Demands on Recall Strategies

“…Circadian variations appear to be less consistent for other psychological measures recorded in several shift work studies, and in particular for self-reported tension (Folkard, 1990;Kecklund et al, 1997;Monk et al, 1985;Owens et al, 2000 ;Prizmic et al, 1995). While some studies reported a circadian trend for perceived tension, others did not, and still others reported an atypical trend.…”

Mnemonic Processing in Air Traffic Controllers: Effects of Task Parameters and Work Organization

“…Likewise, in agreement with the proposal that the impact of output interference and response set size is reduced in probe recognition compared to free recall (Cowan, Saults, & Brown, 2004), presentation modality and list length affected recognition only in the presence of an additional disrupting factor (time of day). Consequently, investigation of the effects of time of day on ATCs' cognitive processes according to the task used and the task components manipulated may improve our understanding of the more general shift work literature (Folkard, 1990;Monk, Fookson, Moline, & Pollak, 1985) and the more specific ATC simulations studies (Gronlund et al, 2005;Means et al, 1988;Schneider et al, 2004;Wickens & Hollands, 2000) as the findings illustrate that participants' alertness affects task performance according to task demands.…”