The self-reported causes of sleepiness in shift-working tram and truck drivers

Identifying the causes of sleepiness in various safety-critical work environments is necessary for implementing more efficient fatigue management strategies. In transportation, little is known about drivers’ own perceptions of these causes. Therefore, we instructed shift-working tram (n = 23) and long-haul truck drivers (n = 52) to report at the end of their shifts what made them sleepy if they felt so. These self-reports, measured on-duty sleepiness, and sleep amounts were recorded on every shift over a period of 2–3 weeks per driver. The causes of sleepiness were queried with smartphone applications and sleep logs. Sleepiness was measured with the Karolinska Sleepiness Scale (KSS) and sleep with wrist-worn actigraphs. Data were analyzed using generalized estimating equations. Sleep loss and insufficient rest breaks were commonly reported as causing sleepiness among the tram drivers, whereas time of day and sleep loss were the leading causes among the truck drivers. Other causes, such as traffic or cabin conditions, were not frequently mentioned. During morning, day, and evening shifts, the truck drivers were less likely to report insufficient rest breaks as causing sleepiness than the tram drivers. Similarly, during morning shifts, the truck drivers were less likely to attribute their sleepiness to sleep loss. In shifts with drives reporting severe sleepiness (KSS ≥ 7 at least once, 18–21% of shifts), sleep loss was significantly reported as causing sleepiness among both groups. Reporting insufficient rest breaks was associated with severe sleepiness among the tram drivers, whereas time of day showed the same among the truck drivers. The results highlight the need for addressing sleep-related fatigue in transportation and provide directions for future research with regard to secondary causes of sleepiness.     

High risk factors of hostage barricade incidents in a Japanese sample

Hostage taking incidents in which the police besiege a particular location are known as hostage barricade incidents. The first aim of the present article was to examine the process of risk assessment in hostage incidents, using a group of police officers as the sample. The second aim was to identify the risk factors involved in hostage incidents and examine the degree of concordance between the risk as assessed by the police officers and the figures obtained from the analysis of actual hostage barricade incidents. For the purpose of this study, a survey was carried out across Japan, and 45 police officers responsible for hostage negotiation responded to the questionnaires. Additionally, a sample of 116 actual hostage barricade incidents that occurred in Japan from 1970 to 2002 was utilised to examine the high risk factors involved in such cases. As per the results, a majority of the police officers (73.3%), in response to an open‐ended question, indicated that the highly excited state of the hostage takers was dangerous for the hostages. Moreover, it was demonstrated in all 116 incidents that several factors such as ‘a long siege’ tended to increase the risk of deaths, though this was very rare (n = 4). On the other hand, the proportion of injuries to the hostages was high in expressive situations such as domestic situations or suicide attempt scenarios. On the whole, the results obtained from the analyses of actual incidents were consistent with those obtained from the police officers' risk assessment in many respects. However, the correlation between the degree of risk as assessed by the police officers and the actual rate of deaths/injuries to the hostages was very low. Copyright © 2004 John Wiley & Sons, Ltd.     

Can we modify maladaptive attributions for fatigue?

Research has shown that those with insomnia focus primarily on their sleep as a cause of daytime fatigue rather than the multitude of other possible causes of fatigue. This can create sleep-related anxiety and further perpetuate the sleep disturbance. In order to lessen the increased focus on sleep, the present study investigated whether people could learn to consider other attributions for fatigue via an information-based manipulation. Undergraduate students (N = 88) were randomized to two information groups: They either received information about common factors that could explain daytime fatigue (the fatigue information condition) or received generic sleep-related information (the control condition). Each group was tested pre- and post-intervention. Fatigue information participants were significantly more likely to consider non-sleep-related attributions for fatigue at post-intervention, relative to control participants. These results demonstrate that attributions for fatigue may be amenable to change via an information-based intervention; thus, this research explores a preliminary step toward investigating refinements to insomnia treatments.     

Book Reviews

Research has shown that those with insomnia focus primarily on their sleep as a cause of daytime fatigue rather than the multitude of other possible causes of fatigue. This can create sleep-related anxiety and further perpetuate the sleep disturbance. In order to lessen the increased focus on sleep, the present study investigated whether people could learn to consider other attributions for fatigue via an information-based manipulation. Undergraduate students (N = 88) were randomized to two information groups: They either received information about common factors that could explain daytime fatigue (the fatigue information condition) or received generic sleep-related information (the control condition). Each group was tested pre- and post-intervention. Fatigue information participants were significantly more likely to consider non-sleep-related attributions for fatigue at post-intervention, relative to control participants. These results demonstrate that attributions for fatigue may be amenable to change via an information-based intervention; thus, this research explores a preliminary step toward investigating refinements to insomnia treatments.     

Individual differences in stress and fatigue in two field studies of driving

This paper reports the findings of two field studies of Australian drivers in which individual differences in stress and fatigue were investigated. In the first study, 58 professional drivers completed measures of mood, fatigue and other subjective stress state measures, before and after performing a prolonged driving trip. The results indicated that the scales were sensitive to increased fatigue following the driving trip, and correlated appropriately with Fatigue Proneness, a driver stress trait. In the second study, 104 non-professional drivers completed identical subjective stress state measures as the professional drivers, before and after performing a driving trip. Drivers completed a measure of driving-related stress traits, the Driver Stress Inventory (DSI), and a measure of coping, the Driving Coping Questionnaire (DCQ). Both measures were predictive of state response to driving, and the association between Fatigue Proneness and post-drive fatigue found in the first study was replicated. Findings from these studies suggest that fatigue and stress reactions to driving are psychometrically distinct, but may have some common antecedents, such as use of emotion-focused coping. The studies confirm the importance of fatigue and stress as potential safety problems, but also highlight the role of individual differences in response to the demands of driving.     

Higher levels of depression are associated with reduced global bias in visual processing

Sleep-related attentional bias is a well-documented finding in patients with primary insomnia. To address the question of whether attentional preference for sleep-related stimuli is due to sleepiness (as measured by the Stanford Sleepiness Scale; SSS) or sleeplessness (as measured by the Pittsburgh Sleep Quality Index; PSQI) we investigated 105 non-clinical participants with two attentional bias tasks, an emotional Stroop task and a newly introduced mixed-modality task. The emotional Stroop task revealed significant positive linear relationships between sleep-related attentional bias and both poor sleep quality and sleepiness. Additionally, we found a significant negative interaction effect between these two variables on the cognitive bias. This means that attentional bias scores are reduced when poor sleep quality is associated with high sleepiness and high sleep quality is associated with low sleepiness. We did not find any significant result in the mixed-modality task. The results suggest that sleep-related attentional bias can be elicited by both sleepiness and sleeplessness.     

The driver vigilance telemetric control system (DVTCS): Investigating sensitivity to experimentally induced sleep loss and fatigue

Vigilance technologies are used in the Australian rail industry to address the risks associated with driver sleepiness and fatigue. The aim of this study was to investigate whether a new device, designed to detect lowered states of arousal using electrodermal activity (EDA), would be sensitive to experimentally induced sleepiness and fatigue. Fifteen individuals (7 of them female, 9 male; 18–32 years of age) spent 3 consecutive days in the laboratory, which included 1 night of sustained wakefulness (28 h). The participants completed a 10-min psychomotor vigilance task (PVT) and fatigue and sleepiness ratings every 2 h, and a 30-min driving simulator every 4 h. As was expected, simulated driving, PVT, and subjective ratings indicated increasing levels of sleepiness and fatigue during sustained wakefulness. The EDA device output did not coincide with these findings. The results indicated that the EDA indicator was not sensitive to increased sleepiness and fatigue at the levels produced in the present study.     

When Fatigue Turns Deadly: The Association Between Fatigue and Racial Bias in the Decision to Shoot

Racial bias in the decision to shoot can be minimized if individuals have ample cognitive resources to regulate automatic reactions. However, when individuals are fatigued, cognitive control may be compromised, which can lead to greater racial bias in shoot/don't-shoot decisions. The current studies provide evidence for this hypothesis experimentally using undergraduate participants (Study 1) and in a correlational design testing police recruits (Study 2). These results shed light on the processes underlying the decision to shoot and, given the high prevalence of fatigue among police officers, may have important practical implications.     

“I'm a police officer not a social worker or mental health nurse”: Online discourses of exclusion and resistance regarding mental health‐related police work

Despite estimates suggesting that around 15% of UK police incidents involve people with a mental health concern, officers receive very little mental health training. The police have faced high‐profile criticisms over their handling of mental health‐related incidents, whereas the underfunding and fragmentation of UK mental health services has led to concerns that police officers are being forced to undertake a primary role in mental health care. At a time of austerity and widespread cuts to public services, it is important to explore how particular groups work to justify the parameters of their professional duties. This article therefore explores the discourses surrounding mental health problems on an online police discussion forum, highlighting two distinct ways in which mental health‐related work is represented as being incompatible with policing. First, mental health problems are delegitimised and conflated with “scrounging,” positioning individuals as undeserving of police time; second, mental health problems are reified and associated with violence and extreme behaviour, justifying the use of force by police officers and deflecting responsibility onto mental health services. Findings are consistent with previous research suggesting that mental health work is not perceived to be a valid part of the police role.     

Mental health of a police force: estimating prevalence of work-related depression in Australia without a direct national measure

The risk of work-related depression in Australia was estimated based on a survey of 631 police officers. Psychological wellbeing and psychological distress items were mapped onto a measure of depression to identify optimal cutoff points. Based on a sample of police officers, Australian workers, in general, are at risk of depression when general psychological wellbeing is considerably compromised. Large-scale estimation of work-related depression in the broader population of employed persons in Australia is reasonable. The relatively high prevalence of depression among police officers emphasizes the need to examine prevalence rates of depression among Australian employees.     

Individual Differences, Situational Constraints, and Police Shooting Incidents

Differences in the personal nature of police officers as well as differences among the situational constraints due to assignments are considered in an examination of the occurrences of police involvement in shooting incidents. The Poisson and negative binomial models used in accident research are considered for representing the occurrence of shooting incidents. Data were gathered from incidents in a large metropolitan police department over a 34-month period and used to test the two models. Various analyses indicate a good Poisson fit. Implications of the data are discussed.     

Job demands,work‐family conflict,and emotional exhaustion in police officers: A longitudinal test of competing theories

We propose and test a comprehensive theory designed to explain seemingly contradictory relations between job demands, emotional exhaustion, and work‐family conflict (WFC) reported in the literature. Using job demands‐resources theory, effort‐recovery theory, and personal resources theory we hypothesized that job demands would spillover to emotional exhaustion as mediated by WFC (causality model), and alternatively that job demands would also spillover to WFC as mediated by emotional exhaustion (reverse causal model). Further, we also hypothesized using loss spiral theory that a more comprehensive model representing reciprocal and cross‐linked effects (causal and reverse causal simultaneously) would best fit the data. The hypotheses were tested in a longitudinal study of 257 Australian (Victorian) frontline police officers at two time points approximately 12 months apart. We used structural equation modelling and found in support of the simultaneous reciprocal effects hypothesis, that the more comprehensive model fitted the data better than either the causality or the reverse causal model. Future research should more comprehensively model the important relationships between job demands, emotional exhaustion, and WFC to reflect their complex interplay. Interventions to reduce work demands arising from work pressure and emotional demands are indicated to prevent conflict at home and emotional exhaustion in police officers.     

Police officers and civilians as witnesses: intergroup biases and memory performance

To compare police officers and civilians with respect to intergroup biases and memory performance in a witness situation, two versions of a film with a simulated, violent robbery were shown to experienced police officers and civilians (university students and police recruits). The perpetrator was either an immigrant or a native Swede. Results showed that the police officers were less ethnocentric in their evaluations of the perpetrator than the civilians. Moreover, police officers showed higher accuracy in their recollections of crime-relevant information in the film. It is suggested that police officers' knowledge of, and experience with, crime incidents helps them to sort out the relevant information in the situation, and this in turn enhances their memory for crime-relevant information. Policing experience may also result in reduced levels of psychological stress, giving police officers more room to form an individuated, rather than stereotypic, interpretation of the perpetrator's behaviour. Alternatively, it may be that police officers have become aware of biasing effects in the presence of outgroup members, and due to the social disapprobation such ethnocentric reactions can elicit, are more motivated to avoid or inhibit such expressions than civilians. © 1997 John Wiley & Sons, Ltd.     

Police officers' credibility judgments: Accuracy and estimated ability

A study was conducted to examine Spanish police officers' and nonofficers' lie‐ and truth‐detection accuracy, as well as their estimated detection ability. The participants were 121 police officers and 146 undergraduates who watched videotaped truthful and deceptive statements. They had to indicate: (1) whether each statement was truthful or deceptive, and (2) how good police officers were, in comparison with the general population, at detecting the truthfulness or deceptiveness of a statement. Results indicate that police officers' accuracy was not higher than that of nonofficers, rather, while the officers reached an accuracy rate close to chance probability, the undergraduates surpassed that probability. Officers had a very strong tendency to judge the statements as deceptive; this made them less accurate than the students in judging the truthful accounts, while both groups reached a similar accuracy when judging the deceptive ones. Both occupational samples considered that the police are more capable of identifying truths and lies than the general population. However, this belief was stronger among the officers themselves than among the nonofficers. No significant correlation between estimated ability and accuracy was found for either sample. The results are explained in terms of the participants' wrong beliefs about the cues to deceit and the socialization process that police officers undergo, which would increase their confidence and perceived ability while hindering their learning of the actual indicators of deceit. The need for officers to receive training is emphasized, and some directions are given on how this training should be carried out.     

A Comparison of the 1988 and 1994 Diagnostic Criteria for Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS) is an illness that involves severe, prolonged fatigue as well as neurological, immunological, and endocrinological system pathology. Because the pathogenesis of CFS has yet to be determined, case definitions have relied on clinical observation in classifying signs and symptoms for diagnosis. In an attempt to address various criticisms and inconsistencies in diagnostic criteria, there have been several revisions of the CFS case definition. The current investigation examined the differences between 1988 and 1994 definitions as well as participants who had a psychiatric explanation for their fatigue. Dependent measures included psychiatric comorbidity, symptom frequency, and functional impairment. The 1988 criteria, compared to the 1994 criteria, appeared to select a group of participants with more symptomatology and functional impairment, but these groups did not significantly differ in psychiatric comorbidity. Implications of these findings are discussed.     

Younger drivers executive functioning and the relationship with experiencing signs of sleepiness

Young drivers are more likely to continue driving when experiencing signs of sleepiness and are over-represented in sleep-related crashes. Adolescence and early adulthood are characterised by comparatively poor executive functioning, and while previous research has demonstrated a link between poor executive functions and several risky driving behaviours, the relationship with sleepy driving is not well understood. Accordingly, the first aim of the current study was to examine the association between executive functions and experiencing the signs of driver sleepiness in a sample of young adult drivers. Additionally, young drivers who have less experience with driving while sleepy, may attribute less importance to the signs of sleepiness as an indicator of underlying sleepiness level. To test this assumption (aim two), the impact of experiencing signs of sleepiness on perceptions of the importance of those signs was examined. Participants included 118 young adults aged between 17 and 25 years, who completed an online survey measuring experiences with the signs of sleepiness while driving, executive functions, and demographic characteristics. This sample of young adults reported having considerable experience with several signs of sleepiness (i.e., yawning, mind wandering, and difficulty keeping eyes while driving). A linear regression analysis found that the demographic variables of age and hours driven per week, as well as the executive function constructs of organization, strategic planning, and impulse control were associated with experiencing signs or sleepiness. Moreover, having experienced more signs of sleepiness was associated with an increased likelihood in rating those signs as important indicators of sleepiness. The current findings suggest both that several high-level cognitive processes as well as levels of experience with driving when experiencing signs of sleepiness contribute to young peoples’ sleepy driving.     

Self‐Reported Beliefs About Verbal Cues Correlate with Deception‐Detection Performance

In this study, we investigated whether people who hold more correct beliefs about verbal cues to deception are also better lie detectors. We investigated police officers and undergraduates' beliefs about (i) cues to deception via an open‐ended question and (ii) 17 specific verbal cues, after which participants were asked to judge the truthfulness of eight video fragments. Results showed that undergraduates and police officers still hold wrongful beliefs about nonverbal cues, but have better insight into verbal cues. Moreover, a better insight in verbal cues was related to an increased accuracy for identifying truthful statements, showing that verbal cues do drive credibility judgments to some extent.Copyright © 2017 John Wiley & Sons, Ltd.     

Effects of anxiety on handgun shooting behavior of police officers: a pilot study

Abstract

The current pilot study aimed at providing an initial assessment of how anxiety influences police officers’ shooting behavior. Seven police officers participated and completed an identical shooting exercise under two experimental conditions: low anxiety, against a non-threatening opponent, and high anxiety (HA), against a threatening opponent who occasionally shot back using colored soap cartridges. Measurements included shooting accuracy, movement times, head/body orientation, and blink behavior. Results showed that under HA, shooting accuracy decreased. Underlying this degradation of performance, participants acted faster and made themselves smaller to reduce the chance of being hit. Furthermore, they blinked more often, leading to increases in the amount of time participants had their eyes closed. Findings provide support for attentional control theory, hereby also pointing to possible interventions to improve police officers’ shooting performance under pressure.