Evaluating the Effects of Stress and Fatigue on Police Officer Response and Recall: A Challenge for Research, Training, Practice and Policy

Oscillatory Neural Correlates of Police Firearms Decision-Making in Virtual Reality

We investigated the neural signatures of expert decision-making in the context of police training in a virtual reality-based shoot/don't shoot scenario. Police officers can use stopping force against a perpetrator, which may require using a firearm and each decision made by an officer to discharge their firearm or not has substantial implications. Therefore, it is important to understand the cognitive and underlying neurophysiological processes that lead to such a decision. We used virtual reality-based simulations to elicit ecologically valid behavior from authorized firearms officers (AFOs) in the UK and matched novices in a shoot/don't shoot task and recorded electroencephalography concurrently. We found that AFOs had consistently faster response times than novices, suggesting our task was sensitive to their expertise. To investigate differences in decision-making processes under varying levels of threat and expertise, we analyzed electrophysiological signals originating from the anterior cingulate cortex. In line with similar response inhibition tasks, we found greater increases in preresponse theta power when participants inhibited the response to shoot when under no threat as compared with shooting. Most importantly, we showed that when preparing against threat, theta power increase was greater for experts than novices, suggesting that differences in performance between experts and novices are due to their greater orientation toward threat. Additionally, shorter beta rebounds suggest that experts were "ready for action" sooner. More generally, we demonstrate that the investigation of expert decision-making should incorporate naturalistic stimuli and an appropriate control group to enhance validity.

Work-Related Stress and Psychological Distress among Law Enforcement Officers: The Carolina Blue Project

Law enforcement is a stressful occupation that places significant psychological demands on those serving in this role. However, little is known about the severity of work-related stress and psychological distress among law enforcement officers (LEOs) in North Carolina (NC). This cross-sectional study examined the severity of work-related stress and psychological distress among 283 LEOs in NC. The Maslach Burnout Inventory, the Operational Police Stress Questionnaire, the Depression, Anxiety, and Stress Scale, and the Post-Traumatic Stress Disorder (PTSD) Checklist were used to assess burnout, operational police stress, depression, anxiety, stress, and PTSD among LEOs. Descriptive statistics, independent t-tests, Mann-Whitney U tests, one-way ANOVA, and Kruskal-Wallis tests were performed. Rural and male LEOs reported higher burnout levels related to depersonalization (i.e., increased mental distance from one's job) compared with their urban and female counterparts. LEOs exposed to toxic materials or performing patrol duties exhibited higher operational police stress levels than those who did not. Caucasian LEOs exhibited higher depression, anxiety, and stress than their African American counterparts. Rural LEOs and LEOs who were exposed to toxic materials displayed higher levels of PTSD than their counterparts. Our findings highlight the need for increased mental health support and better working environments for LEOs.

The moderation effects of task attributes and mental fatigue on post-interruption task performance in a concurrent multitasking environment

In a concurrent multitasking environment, performing many types of tasks increases task complexity, and working long hours makes a person susceptible to mental fatigue. Emerging technologies may lead to more task interruptions. This study examines the effects of task attributes and mental fatigue on interrupted task performance in a concurrent multitasking environment. Thirty-four participants performed the MATB-Ⅱ under eight conditions (two-level task interruption, two-level task complexity, two-level fatigue). The results revealed the significant interaction effects of interruption × task complexity and of interruption × fatigue state. The findings show that more time is required to return to a complex primary task, and there are differences among subtask types. Mental fatigue negatively affects primary task performance, workload, and the resumption lag after an interruption. The findings are explained by the increasing information cues needed to resume complex tasks and the negative effect of fatigue on memory activation.

Pistol Shooting Performance Correlates with Respiratory Muscle Strength and Pulmonary Function in Police Cadets

Breathing patterns play a crucial role in shooting performance; however, little is known about the respiratory muscle strength and pulmonary capacities that control these patterns. The present study aimed to examine the relationship between shooting performance, respiratory muscle strength, and pulmonary function and to determine differences in respiratory capacities according to the shooting performance categories in police cadets. One hundred sixty-seven police cadets were recruited to assess respiratory muscle strength, pulmonary function, and shooting performance in a well-controlled environment. Measurements included maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), slow vital capacity (SVC), maximal voluntary ventilation (MVV), and pistol shooting scores. The shooting score had a moderate positive correlation with MIP (ρ = 0.33) and MEP (ρ = 0.45). FVC (ρ = 0.25), FEV1 (ρ = 0.26), SVC (ρ = 0.26) (p < 0.001) and MVV (ρ = 0.21) (p < 0.05) were slightly correlated with shooting score. There were differences between shooting performance categories in MIP, MEP, FVC, FEV1, SVC, and MVV (p < 0.001, p < 0.05). The results imply that both strong respiratory muscles and optimal pulmonary function may be one of the necessary prerequisites for superior shooting performance in police.

Perspectives from law enforcement officers who respond to overdose calls for service and administer naloxone

BACKGROUND

Many law enforcement agencies across the United States equip their officers with the life-saving drug naloxone to reverse the effects of an opioid overdose. Although officers can be effectively trained to administer naloxone, and hundreds of law enforcement agencies carry naloxone to reverse overdoses, little is known about what happens on scene during an overdose call for service from an officer's perspective, including what officers perceive their duties and responsibilities to be as the incident evolves.

METHODS

The qualitative study examined officers' experiences with overdose response, their perceived roles, and what happens on scene before, during, and after an overdose incident. In-person interviews were conducted with 17 officers in four diverse law enforcement agencies in the United States between January and May 2020.

RESULTS

Following an overdose, the officers described that overdose victims are required to go to a hospital or they are taken to jail. Officers also described their duties on scene during and after naloxone administration, including searching the belongings of the person who overdosed and seizing any drug paraphernalia.

CONCLUSION

These findings point to a pressing need for rethinking standard operating procedures for law enforcement in these situations so that the intentions of Good Samaritan Laws are upheld and people get the assistance they need without being deterred from asking for future help.

Marital Conflict, Trauma Exposure, PTSD and Depressive Symptoms among Malaysian Firefighters

Multiple exposures to life threatening events may lead to various mental health issues and indirectly affect the marriage of those affected. Very few studies have investigated trauma exposure, PTSD, depressive symptoms, and marital conflicts among firefighters, a group that faces such exposure occupationally. The present study explores the relationship between trauma exposure, PTSD and depression in relation to marital conflicts among firefighters in Sarawak, adopting a cross-sectional research design. Different marital status reported significant PTSD and depressive symptoms. The widowed scored higher PTSD and depressive symptoms than the married and single groups. Firefighters with PTSD and depressive symptoms reported having more problems in aggression family history of distress, sexual dissatisfaction, and problem-solving communication than those without. Regression analysis showed that problem solving communication (t (212) = 2.59, p = .01) and global distress scores (t (212) = 2.17, p < .05) in type of marital conflicts, served as a significant predictor for depressive symptoms. The present study suggests that proper planning for treatment and intervention is needed to improve psychological well-being among firefighters and other high-risk professions following multiple exposures to traumatic events in carrying their job duty. Proper intervention programs also should be initiated for spouses of firefighters dealing with traumatized partners.

A Reasonable Officer: Examining the Relationships Among Stress, Training, and Performance in a Highly Realistic Lethal Force Scenario

Under conditions of physiological stress, officers are sometimes required to make split-second life-or-death decisions, where deficits in performance can have tragic outcomes, including serious injury or death and strained police-community relations. The current study assessed the performance of 122 active-duty police officers during a realistic lethal force scenario to examine whether performance was affected by the officer's level of operational skills training, years of police service, and stress reactivity. Results demonstrated that the scenario produced elevated heart rates (i.e., 150 beats per minute), as well as perceptual and cognitive distortions, such as tunnel vision, commensurate with those observed in naturalistic use of force encounters. The average performance rating from the scenario was 59%, with 27% of participants making at least one lethal force error. Elevated stress reactivity was a predictor of poorer performance and increased lethal force errors. Level of training and years of police service had differential and complex effects on both performance and lethal force errors. Our results illustrate the need to critically reflect on police training practices and continue to make evidence-based improvements to training. The findings also highlight that while training may significantly improve outcomes, flawless performance is likely not probable, given the limits of human performance under stress. Implications for the objective reasonableness standard, which is used to assess the appropriateness of force in courts of law, are discussed.

Fatigue-Related Effects in the Process of Task Interruption on Working Memory

Interruption generally has a negative effect on performance by affecting working memory (WM). However, the neural mechanism of interruption has yet to be understood clearly, and previous studies have largely ignored the role of fatigue state. To address these issues, the present study explores the behavioral and electrophysiological effects of interruption on WM performance using electroencephalography (EEG) data. The moderating effect of fatigue is also explored. The participants performed spatial 2-back tasks with math task interruption, suspension interruption, and non-interruption under different fatigue states. The results show that interruption led to increased alpha activity and P300 amplitude, indicating inhibitory control to interference from irrelevant information. Analysis of P200 amplitude revealed that interruption affected attentional reallocation when resuming the primary task. Increased theta power indicated an increased demand for information maintenance during the interruption. A speeding-up effect was discovered after interruption; however, fatigue impaired cognitive ability and further exacerbated the negative effects of interruption on WM and behavioral performance. These findings contribute to a better understanding of cognitive activity during the interruption and of the interaction with fatigue, and provide further support for the theory of memory for goals (MFG).

Perception during use of force and the likelihood of firing upon an unarmed person

Stress can impact perception, especially during use-of-force. Research efforts can thus advance both theory and practice by examining how perception during use-of-force might drive behavior. The current study explored the relationship between perceptual judgments and performance during novel close-combat training. Analyses included perceptual judgments from close-combat assessments conducted pre-training and post-training that required realistic use-of-force decisions in addition to an artificially construed stress-inoculation event used as a training exercise. Participants demonstrated significant reductions in situational awareness while under direct fire, which correlated to increased physiological stress. The initial likelihood of firing upon an unarmed person predicted the perceptual shortcomings of later stress-inoculation training. Subsequently, likelihood of firing upon an unarmed person was reduced following the stress-inoculation training. These preliminary findings have several implications for low or zero-cost solutions that might help trainers identify individuals who are underprepared for field responsibilities.

Perceived occupational risk of fentanyl exposure among law enforcement

BACKGROUND

Although toxicologists, medical professionals, and service providers have determined that the risk of overdose from fentanyl exposure is extremely low for law enforcement and other first responders, hundreds of media and social media accounts contradict these facts, making these civil servants unnecessarily concerned about such occupational hazards.

METHODS

We conducted a qualitative study to explore knowledge and fear of fentanyl exposure by interviewing 23 law enforcement leaders and officers in five diverse law enforcement agencies in the United States.

RESULTS

Nearly all leaders and officers interviewed wrongly believed that dermal exposure to fentanyl was deadly and expressed fear about such exposure on scene. Officers had a lack of education about fentanyl exposure and faulty or dubious sources of information about it.

CONCLUSION

There is a substantial, pressing need for dissemination of research about the lack of overdose risk associated with dermal fentanyl exposure through channels that law enforcement trust, including through basic academy, in-service training, and law enforcement bulletins and newsletters.

Women demonstrate lower markers of stress and oxidative stress during active shooter training drill

It has been well documented that police officers are frequently engaged in a variety of high stress situations during their normal daily tasks, such as civilian encounters where force is needed or domestic violence situations, that cause significant increases in a variety of physiological and psychological stress markers. Chronic exposure to stressors increases risk for cardiovascular disease (CVD) progression. The purpose of this study was to compare male and female salivary and blood markers of stress in response to an active shooter training drill (ASD) to determine if acute stress differentially impacts men and women to better understand if interventions should be targeted. Thirty-one participants (males ​= ​15 [mean age: 23], females ​= ​16 [mean age: 21]) participated in an ASD involving professional actors playing the role of one active gunman, as well as four victims. The ASD lasted approximately 50 seconds. Blood samples were collected 15 ​min prior as well as after the ASD and analyzed for epinephrine (EPI), norepinephrine (NE), and hydrogen peroxide (H₂O₂) levels. Saliva samples were collected 30 and 5 ​min prior to the ASD and 5 and 30 ​min after the ASD, and were analyzed for cortisol, α-amylase, uric acid, and secretory immunoglobulin-A (SIgA). Our analysis revealed that acute (~50 ​sec) psychological stress in the form of an ASD resulted in significant increases in blood and salivary stress and oxidative stress markers in both men and women. However, four of the seven markers were lower in female participants (cortisol, uric acid, H₂O₂, and α-amylase presented significant main effects for sex). In addition, SIgA was significantly lower in women compared to men 30 ​min prior to, and five min post ASD. These findings suggest females may be at a lower risk to stress induced oxidative stress and CVD.

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Acute psychological stress results in significant increases in blood and saliva stress and oxidative stress markers.

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Stress markers were attenuated in female participants.

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Blood oxidative stress was lower in female participants.

The effects of stress on eyewitness memory: A survey of memory experts and laypeople

This survey examined lay and expert beliefs about statements concerning stress effects on (eyewitness) memory. Thirty-seven eyewitness memory experts, 36 fundamental memory experts, and 109 laypeople endorsed, opposed, or selected don't know responses for a range of statements relating to the effects of stress at encoding and retrieval. We examined proportions in each group and differences between groups (eyewitness memory experts vs. fundamental memory experts; experts vs. laypeople) for endorsements (agree vs. disagree) and selections (don't know vs. agree/disagree). High proportions of experts from both research fields agreed that very high levels of stress impair the accuracy of eyewitness testimony. A majority of fundamental experts, but not eyewitness experts, endorsed the idea that stress experienced during encoding can enhance memory. Responses to statements regarding moderating factors such as stressor severity and detail type provided further insight into this discrepancy. Eyewitness memory experts more frequently selected the don't know option for neuroscientific statements regarding stress effects on memory than fundamental memory experts, although don't know selections were substantial among both expert groups. Laypeople's responses to eight of the statements differed statistically from expert answers on topics such as memory in children, in professionals such as police officers, for faces and short crimes, and the existence of repression, providing insight into possible 'commonsense' beliefs on stress effects on memory. Our findings capture the current state of knowledge about stress effects on memory as reflected by sample of experts and laypeople, and highlight areas where further research and consensus would be valuable.

The impact of the COVID-19 pandemic on European police officers: Stress, demands, and coping resources

PURPOSE

Facing the COVID-19 pandemic, police officers are confronted with various novel challenges, which might place additional strain on officers. This mixed-method study investigated officers' strain over a three-month-period after the lockdown.

METHODS

In an online survey, 2567 police officers (77% male) from Austria, Germany, Switzerland, the Netherlands, and Spain participated at three measurement points per country in spring, 2020. Three-level growth curve models assessed changes in strain and its relation to stressor appraisal, emotion regulation, and preparedness through training. To add context to the findings, free response answers about officers' main tasks, stressors, and crisis measures were coded inductively.

RESULTS

On average, officers seemed to tolerate the pandemic with slight decreases in strain over time. Despite substantial variance between countries, 66% of the variance occurred between individuals. Sex, work experience, stressor appraisal, emotion regulation, and preparedness significantly predicted strain. Risk of infection and deficient communication emerged as main stressors. Officers' reports allowed to derive implications for governmental, organizational, and individual coping strategies during pandemics.

CONCLUSION

Preparing for a pandemic requires three primary paths: 1) enacting unambiguous laws and increasing public compliance through media communication, 2) being logistically prepared, and 3) improving stress regulation skills in police training.

The Impact of Acute Stress Physiology on Skilled Motor Performance: Implications for Policing

Investigations of police performance during acutely stressful situations have primarily focused on higher-order cognitive processes like attention, affect or emotion and decision-making, and the behavioral outcomes of these processes, such as errors in lethal force. However, behavioral outcomes in policing must be understood as a combination of both higher-order processes and the physical execution of motor skills. What is missing from extant police literature is an understanding of how physiological responses to acute stress contribute to observed decrements in skilled motor performance at the neuromuscular level. The purpose of the current paper is to fill this knowledge gap in the following ways: (1) review scientific evidence for the physiological (i.e., autonomic, endocrine, and musculoskeletal) responses to acutely stressful exposures and their influence on skilled motor performance in both human and animal models, (2) review applied evidence on occupationally relevant stress physiology and observed motor decrements in performance among police, and (3) discuss the implications of stress physiology for police training and identify future directions for applied researchers. Evidence is compelling that skill decay is inevitable under high levels of acute stress; however, robust evidence-informed training practices can help mitigate this decay and contribute to officer safety.

Complex Motor Learning and Police Training: Applied, Cognitive, and Clinical Perspectives

The practices surrounding police training of complex motor skills, including the use of force, varies greatly around the world, and even over the course of an officer’s career. As the nature of policing changes with society and the advancement of science and technology, so should the training practices that officers undertake at both central (i.e., police academy basic recruit training) and local (i.e., individual agency or precinct) levels. The following review is intended to bridge the gap between scientific knowledge and applied practice to inform best practices for training complex motor skills that are unique and critical to law enforcement, including the use of lethal force. We begin by providing a basic understanding of the fundamental cognitive processes underlying motor learning, from novel skill acquisition to complex behaviors including situational awareness, and decision-making that precede and inform action. Motor learning, memory, and perception are then discussed within the context of occupationally relevant stress, with a review of evidence-based training practices that promote officer performance and physiological responses to stress during high-stakes encounters. A lack of applied research identifying the neurophysiological mechanisms underlying motor learning in police is inferred from a review of evidence from various clinical populations suffering from disorders of cognitive and motor systems, including Alzheimer’s and Parkinson’s disease and stroke. We conclude this review by identifying practical, organizational, and systemic challenges to implementing evidence-based practices in policing and provide recommendations for best practices that will promote training effectiveness and occupational safety of end-users (i.e., police trainers and officers).

Differential Effects of Physiological Arousal Following Acute Stress on Police Officer Performance in a Simulated Critical Incident

Background: Police officer response in a critical incident is often a life-or-death scenario for the officer, the suspect, and the public. Efficient and accurate decisions are necessary to ensure the safety of all involved. Under these conditions, it is important to understand the effects of physiological arousal in response to acute stress on police officer performance in critical and dangerous incidents. Prior research suggests that physiological arousal following a stressor differentially affects police performance – communication may be impaired, whereas well-rehearsed, tactical behaviors may be resilient.

Objectives: In this study, we examine the differential effects of physiological arousal across three police skill domains: verbal communication, nonverbal communication, and tactical skill.

Methods: A sample of Swedish police cadets (N = 17) participated in a critical incident simulation, which was a reenactment of a real-life incident that had resulted in a police officer death; the simulation included multiple calls, dynamic environments, and surprise threats. An expert rater evaluated the cadets across multiple domains of skill, and physiological arousal was monitored by continuous heart rate monitoring and measures of circulating cortisol and antithrombin taken before and after the incident simulation.

Results: The simulation increased police officer arousal, as reflected in elevated heart rate, but this alone did not predict differences in performance. Greater increase in antithrombin was associated with better general performance, but a specific deficit in verbal communication as compared to tactical performance and nonverbal communication. Change in cortisol was unrelated to the skill assessments.

Conclusions: Police officer performance during a critical incident simulation is affected by physiological arousal. The findings are discussed with implications for police officer decision-making and real-world performance.