Subjective fatigue of C-141 aircrews during Operation Desert Storm.
ABSTRACT Airlift crews were exposed to extended work periods, reduced sleep periods, night work, and circadian dysrhythmia caused by shift work and time-zone crossings during Operations Desert Shield and Desert Storm. This research reveals the extent to which severe subjective fatigue was experienced by the crews during Operation Desert Storm. In addition, through the evaluation of long-term and short-term work and sleep histories, this research shows that recent sleep and flight histories are correlated with high fatigue levels. Furthermore, we found a tendency for fatigue to correspond with pilot error. We recommend that the training of personnel involved in long-duration operations include fatigue management strategies and, further, that work policies and environments be designed to take into account the importance of regular and restorative sleep when unusual duty hours are required.
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- "Harrison and Horne, 1997, 1998). Sleep deprivation has also been reported to increase the number of inaccuracies in sending and receiving messages (Neville et al., 1994; Schein, 1957). The later findings may imply difficulties in language comprehension as well as language generation after mild to moderate sleep loss. "
ABSTRACT: The present study examined the impact of mild (24 h) sleep deprivation and of the circadian rhythm on auditory temporal resolution, measured by dichotic temporal order judgment (TOJ). The rationale for the present study was based on several areas of research. First, the 'sleep-based neuropsychological perspective' hypothesis posits that sleep reduction initially impacts the functions associated with intact prefrontal cortical activity, e.g. language tasks. Secondly, recent studies indicate the importance of the role of auditory temporal resolution in speech comprehension. Thirdly, there is accumulating evidence of the involvement of prefrontal cortical structures in auditory temporal resolution. We hypothesized that mild to moderate sleep deprivation would affect dichotic TOJ negatively. The results showed that: (1) 24 h of sleep deprivation significantly reduced the overall level of accuracy in dichotic TOJ and increased dichotic TOJ threshold from 57.61 ms to 73.93 ms, a reduction in temporal resolution of 28.3%; (2) dichotic TOJ was subject to a small, but significant diurnal rhythm having a nadir in early to mid afternoon. As auditory temporal resolution of speech and non-speech sounds seems to be dependent on intact functioning of the left inferior and left dorso-lateral prefrontal cortex (PFC), these data strengthen the argument that even mild to moderate sleep deprivation can impact negatively on PFC-dependent functions. Furthermore, based on these findings, we suggest that the deficit in auditory temporal resolution in individuals suffering from sleep loss may also affect language comprehension. http://www.ariel.ac.il/research/apl/publicationsJournal of Sleep Research 04/2005; 14(1):7-15. DOI:10.1111/j.1365-2869.2004.00423.x · 2.95 Impact Factor
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ABSTRACT: Despite knowledge gained through decades of research, fatigue due to insuffi cient sleep remains an ingrained part of military and commercial aviation and represents a major threat to the health, safety, and effectiveness of aircrew. Long duty periods, high workloads, circadian disruptions, and insuffi cient recovery time between fl ights ensure sleepiness is a continued problem for both civilian and military aircrew. The majority of our knowledge concerning the effects of fatigue is gained from acute, total sleep deprivation laboratory-based studies which describe results in terms of the average indi-vidual's response to total sleep loss. However, in operational environments, limited sleep over many days, termed chronic sleep restriction, is more commonly experienced than acute, total sleep deprivation, casting some doubt on the opera-tional applicability of many previous studies. Furthermore, recent studies have identifi ed strong individual differences in fatigue resistance. Our understanding of the effects of chronic sleep restriction and the individual differences in response to fatigue is currently limited in comparison to that of acute sleep deprivation. In this review, we identify the substantial progress made over the last 2 decades in closing these gaps. Advances in understanding the effects of chronic sleep re-striction, the recovery timeline associated with sleep loss, and individual responses to sleep loss represent a critical step in the improvement of current, and the formulation of future, countermeasures in the aviation environment. Adjustments to duty rotation and crew scheduling, refi nement of biomathematical models of fatigue, and application of currently avail-able countermeasures are the most immediate of these improvements.