Sleep deprivation in Air National Guard medical personnel responding to simulated disaster-training exercises

National Guard personnel remain largely unstudied within the sleep research community, despite their unique and important role. In response, the purpose of this study was to investigate the extent of sleep deprivation in National Guard medical personnel from two separate Air Force Bases (AFBs) responding to simulated disaster-training exercises. National Guard medical personnel (N = 77) were fitted with wrist activity monitors (actigraphy) to objectively measure their sleep for 4 days of their civilian time (baseline), followed by a 4-day transition period from civilian to military duty, and a 3–5-day disaster-training exercise. Differences in sleep quantity, quality, and “cognitive effectiveness” were analyzed using generalized linear mixed models. Participants’ sleep quantity was significantly reduced from civilian to disaster-training periods, and their cognitive effectiveness also dropped significantly. National Guard medical personnel were sleep-deprived during a simulated disaster-training exercise, which, although a valid proxy for real-world disasters, is likely to be a conservative approximation of the stress and fatigue National Guard personnel experience during crisis response. As such, the need for targeted fatigue-related interventions to safeguard our service members during these critical times is clear.     

Suppression-induced forgetting diminishes following a delay of either sleep or wake

ABSTRACT

We investigated the duration of suppression-induced forgetting (SIF), and the extent to which retrieval suppression differs between negative and neutral memories. We further examined if SIF was differently affected by sleep versus wake during the delay interval between retrieval suppression and re-test. Fifty participants first learned to associate neutral words with either neutral or negative images. Then, a subset of the words was shown again, and participants were asked to either recall (Think), or to suppress retrieval of (No-Think) the associated images. Finally, a memory test for all items was performed either immediately after the Think/No-Think (T/NT) phase (No Delay), or after a 3.5?h delay interval containing either sleep or wake. Results revealed a SIF effect only in the No Delay group, indicating that this forgetting effect dissipates already after a 3.5?h delay interval. Negative items were experienced as more intrusive than neutral ones during the T/NT phase.     

Efficacy of proxy definitions for identification of fatigue/sleep-related crashes: An Australian evaluation

Fatigue/sleepiness is recognised as an important contributory factor in fatal and serious injury road traffic incidents (RTIs), however, identifying fatigue/sleepiness as a causal factor remains an uncertain science. Within Australia attending police officers at a RTI report the causal factors; one option is fatigue/sleepiness. In some Australian jurisdictions police incident databases are subject to post hoc analysis using a proxy definition for fatigue/sleepiness. This secondary analysis identifies further RTIs caused by fatigue/sleepiness not initially identified by attending officers. The current study investigates the efficacy of such proxy definitions for attributing fatigue/sleepiness as a RTI causal factor. Over 1600 Australian drivers were surveyed regarding their experience and involvement in fatigue/sleep-related RTIs and near-misses during the past five years. Driving while fatigued/sleepy had been experienced by the majority of participants (66.0% of participants). Fatigue/sleep-related near misses were reported by 19.1% of participants, with 2.4% being involved in a fatigue/sleep-related RTI. Examination of the characteristics for the most recent event (either a near miss or crash) found that the largest proportion of incidents (28.0%) occurred when commuting to or from work, followed by social activities (25.1%), holiday travel (19.8%), or for work purposes (10.1%). The fatigue/sleep related RTI and near-miss experience of a representative sample of Australian drivers does not reflect the proxy definitions used for fatigue/sleepiness identification. In particular those RTIs that occur in urban areas and at slow speeds may not be identified. While important to have a strategy for identifying fatigue/sleepiness related RTIs proxy measures appear best suited to identifying specific subsets of such RTIs.     

Anxiety sensitivity and daily cigarette smoking in relation to sleep disturbances in treatment-seeking smokers

ABSTRACT

Although the association between anxiety and sleep disturbance is well-documented, the underlying mechanisms are less clear. Anxiety sensitivity (AS), the fear of physiological arousal and bodily sensations, is a risk factor for anxiety and poor sleep. Smoking also contributes to poor sleep and may compound the effects of AS on sleep quality. This study evaluated the main and interactive effects of AS and cigarettes/day on sleep quality among smokers. Participants (n = 190) were adult treatment-seeking daily smokers who completed a baseline assessment as part of a larger smoking cessation trial. Sleep quality was self-reported. Results indicated that AS was significantly correlated with greater disturbance in sleep duration, subjective sleep quality, sleep onset latency, sleep disturbance, daytime dysfunction, and sleep medication use. There was a significant interaction between AS and cigarettes/day in terms of sleep onset latency, but not other sleep quality indices. AS was associated with significantly longer sleep onset latency minutes among heavier smokers, but not lighter smokers. Specifically, the association between AS and sleep onset latency was significant for those who smoked ≥ 33 cigarettes/day. AS is a psychological factor that may contribute to poor sleep quality, especially in heavy smokers, and thus may be a promising intervention target.