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Flood A, Keegan RJ. Cognitive Resilience to Psychological Stress in Military Personnel. Front Psychol 2022; 13:809003. [PMID: 35369170 PMCID: PMC8966027 DOI: 10.3389/fpsyg.2022.809003] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/17/2022] [Indexed: 11/30/2022] Open
Abstract
Military personnel often perform complex cognitive operations under unique conditions of intense stress. This requirement to perform diverse physical and mental tasks under stress, often with high stakes, has led to recognition of the term 'tactical athlete' for these performers. Impaired cognitive performance as a result of this stress may have serious implications for the success of military operations and the well-being of military service men and women, particularly in combat scenarios. Therefore, understanding the nature of the stress experienced by military personnel and the resilience of cognitive functioning to this stress is of great importance. This review synthesises the current state of the literature regarding cognitive resilience to psychological stress in tactical athletes. The experience of psychological stress in military personnel is considered through the lens of the Transactional Theory of stress, while offering contemporary updates and new insights. Models of the effects of stress on cognitive performance are then reviewed to highlight the complexity of this interaction before considering recent advancements in the preparation of military personnel for the enhancement of cognitive resilience. Several areas for future research are identified throughout the review, emphasising the need for the wider use of self-report measures and mixed methods approaches to better reflect the subjective experience of stress and its impact on the performance of cognitive operations.
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Affiliation(s)
- Andrew Flood
- University of Canberra Research Institute for Sport and Exercise, University of Canberra, Bruce, ACT, Australia
- Discipline of Psychology, Faculty of Health, University of Canberra, Bruce, ACT, Australia
| | - Richard J. Keegan
- University of Canberra Research Institute for Sport and Exercise, University of Canberra, Bruce, ACT, Australia
- Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, Bruce, ACT, Australia
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2
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Tait JL, Drain JR, Corrigan SL, Drake JM, Main LC. Impact of military training stress on hormone response and recovery. PLoS One 2022; 17:e0265121. [PMID: 35271678 PMCID: PMC8912193 DOI: 10.1371/journal.pone.0265121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 02/23/2022] [Indexed: 11/19/2022] Open
Abstract
Objectives
Military personnel are required to train and operate in challenging multi-stressor environments, which can affect hormonal levels, and subsequently compromise performance and recovery. The aims of this project were to 1) assess the impact of an eight-day military training exercise on salivary cortisol and testosterone, 2) track the recovery of these hormones during a period of reduced training.
Methods
This was a prospective study whereby 30 soldiers (n = 27 men, n = 3 women) undergoing the Australian Army combat engineer ‘Initial Employment Training’ course were recruited and tracked over a 16-day study period which included an eight-day military training exercise. Non-stimulated saliva samples were collected at waking, 30 min post waking, and bedtime on days 1, 5, 9, 13, 15; measures of subjective load were collected on the same days. Sleep was measured continuously via actigraphy, across four sequential study periods; 1) baseline (PRE: days 1–4), 2) field training with total sleep deprivation (EX-FIELD: days 5–8), 3) training at simulated base camp with sleep restriction (EX-BASE: days 9–12), and 4) a three-day recovery period (REC: days 13–15).
Results
Morning cortisol concentrations were lower following EX-FIELD (p<0.05) compared to the end of REC. Training in the field diminished testosterone concentrations (p<0.05), but levels recovered within four days. Bedtime testosterone/cortisol ratios decreased following EX-FIELD and did not return to pre-training levels.
Conclusions
The sensitivity of testosterone levels and the testosterone/cortisol ratio to the period of field training suggests they may be useful indicators of a soldier’s state of physiological strain, or capacity, however inter-individual differences in response to a multi-stressor environment need to be considered.
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Affiliation(s)
- Jamie L. Tait
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- * E-mail:
| | - Jace R. Drain
- Defence Science and Technology Group, Fisherman’s Bend, Australia
| | - Sean L. Corrigan
- School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Jeremy M. Drake
- School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Luana C. Main
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
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Schlatter S, Guillot A, Faes C, Saruco E, Collet C, Di Rienzo F, Debarnot U. Acute stress affects implicit but not explicit motor imagery: A pilot study. Int J Psychophysiol 2020; 152:62-71. [DOI: 10.1016/j.ijpsycho.2020.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/30/2022]
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4
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Schwartz A, Gerberich SG, Albin T, Kim H, Ryan AD, Church TR, Green DR, McGovern PM, Erdman AG, Arauz RF. The association between janitor physical workload, mental workload, and stress: The SWEEP study. Work 2020; 65:837-846. [PMID: 32310213 DOI: 10.3233/wor-203135] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Approximately 2.38 million janitors are employed in the U.S. While high physical workload may explain a lost-work days rate 2.7 times greater than other occupations, little is known about the association between janitors' physical workload, mental workload, and stress. OBJECTIVE The objective of this study was to assess the associations between physical (ergonomic) and mental workload exposures and stress outcomes among janitors. METHODS Questionnaire data, focused on ergonomic workload, mental workload and stress, were collected from Minnesota janitors for a one-year period. Physical workload was assessed with Borg Scales and Rapid Entire Body Assessments (REBA). Mental workload assessment utilized the NASA Task Load Index (TLX). Stress assessments utilized single-item ordinal stress scale (SISS) and Perceived Stress Scale-4 (PSS-4) measures. Descriptive and multivariable analyses, including bias adjustment, were conducted. RESULTS Odds ratios (OR) and 95% confidence intervals (CI) for ergonomic workload (task frequency) effects on SISS were: REBA (1.18 OR, 1.02-1.37 CI); Borg (1.25 OR, 1.00-1.56 CI); combined REBA and Borg (1.10 OR, 1.01-1.20 CI). Mental workload was associated with higher PSS-4 levels (0.15 Mean Difference, 0.08-0.22 CI) and a 3% increased risk for each one-unit increase in the SISS scale (1.03 OR, 1.02-1.05 CI). CONCLUSIONS This research demonstrated a moderate effect of physical and mental workloads on stress among janitors.
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Affiliation(s)
- Adam Schwartz
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Susan Goodwin Gerberich
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Thomas Albin
- High Plains Engineering Services, Minneapolis, MN, USA
| | - Hyun Kim
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Andrew D Ryan
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Timothy R Church
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Deirdre R Green
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Patricia M McGovern
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Arthur G Erdman
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Rony F Arauz
- Midwest Center for Occupational Health and Safety Education and Research Center, Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, MN, USA
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5
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The Interplay Between Post-traumatic Stress Disorder and Dementia: A Systematic Review. Am J Geriatr Psychiatry 2020; 28:48-60. [PMID: 31488352 DOI: 10.1016/j.jagp.2019.08.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 11/21/2022]
Abstract
BACKGROUND Post-traumatic stress disorder (PTSD) has been reported to increase the risk for dementia in veterans and civilians. Conversely, case reports have described the delayed onset of PTSD in individuals developing dementia, suggesting a complex relationship between these two conditions. OBJECTIVES To critically review studies investigating the association between PTSD and dementia and to assess the evidence for a bidirectional relationship between the two conditions. METHODS A systematic review of Web of Science Core databases was carried out from inception of databases up to November 2018 to identify observational studies pertaining to both PTSD and dementia. Populations enrolled, stressors and neuropathologies, and main outcomes of studies were extracted, in addition to age at trauma and at onset of PTSD and dementia. The different temporal relationships between trauma and onset of the conditions were characterized. RESULTS Twenty-five articles were included in the review; 14 articles assessed the association of PTSD with subsequent dementia and 11 articles reported the delayed onset of PTSD with the onset of dementia. Most reported traumas occurred in early-life (<40 years) and were related to war combat experiences. PTSD in mid-life (between 40 and 60 years of age) was associated with an increased risk of late-onset dementia. Numerous case series reported the delayed onset of PTSD in Alzheimer's disease and vascular dementia. CONCLUSION Current evidence suggests that PTSD and dementia have a bidirectional relationship: PTSD increases the risk for late-onset dementia and dementia increases the risk for delayed-onset PTSD in those who experienced a significant trauma earlier in life.
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Dinces SM, Rowell LN, Benson J, Hile SN, Tang AC, Annett RD. Normalized Cortisol Reactivity Predicts Future Neuropsychological Functioning in Children With Mild/Moderate Asthma. Front Psychol 2019; 10:2570. [PMID: 31803112 PMCID: PMC6877752 DOI: 10.3389/fpsyg.2019.02570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 10/30/2019] [Indexed: 12/28/2022] Open
Abstract
Cortisol reactivity to adrenocorticotropic hormone (ACTH) has been associated with neuropsychological processes including attention and memory in children with asthma. While cortisol reactivity to a psychological stressor is often considered a measure of current neuroendocrine functioning, this study examines the association of the cortisol reactivity and subsequent neuropsychological functioning. Using prospective data from the Childhood Asthma Management Program (CAMP), we explored the predictive ability of cortisol reactivity to ACTH and children's later attention and memory using traditional and an alternative cortisol reactivity (normalized cortisol) measures. Cortisol reactivity was assessed at study entry and 1-year follow-up, and neuropsychological functioning was assessed at 3-year follow-up. Cortisol reactivity was assessed through plasma cortisol concentrations collected at baseline (CORTBASELINE) and 30 min post-ACTH challenge (CORTPOST-A CTH). An alternative measure of cortisol reactivity was developed through post-ACTH stimulation cortisol, normalized by cortisol by baseline (CORTNORM -ACTH). CORT B ASELINE positively predicted year 3 attention, while CORTNORM -ACTH negatively predicted attention, suggesting convergence of cortisol variables in prediction of neuropsychological function. Year 1 CORTACTH positively predicted child memory at year 3; Year 1 CORTNORM-ACTH negatively predicted year 3 sustained attentions. These findings demonstrate that HPA reactivity, including the application of normalized cortisol reactivity, can predict subsequent neuropsychological functioning of children with mild to moderate asthma.
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Affiliation(s)
- Sarah M. Dinces
- Department of Psychology, The University of New Mexico, Albuquerque, NM, United States
| | - Lauren N. Rowell
- Department of Psychology, The University of New Mexico, Albuquerque, NM, United States
| | - Jennifer Benson
- Department of Psychology, The University of New Mexico, Albuquerque, NM, United States
| | - Sarah N. Hile
- Department of Psychology, The University of New Mexico, Albuquerque, NM, United States
| | - Akaysha C. Tang
- Faculty of Education, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Robert D. Annett
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS, United States
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Anderson GS, Di Nota PM, Metz GAS, Andersen JP. The Impact of Acute Stress Physiology on Skilled Motor Performance: Implications for Policing. Front Psychol 2019; 10:2501. [PMID: 31781001 PMCID: PMC6856650 DOI: 10.3389/fpsyg.2019.02501] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/22/2019] [Indexed: 12/26/2022] Open
Abstract
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.
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Affiliation(s)
- G S Anderson
- Office of Applied Research and Graduate Studies, Justice Institute of British Columbia, New Westminster, BC, Canada
| | - P M Di Nota
- Office of Applied Research and Graduate Studies, Justice Institute of British Columbia, New Westminster, BC, Canada.,Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - G A S Metz
- Department of Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
| | - J P Andersen
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
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Taverniers J, Suss J. A user-centred assessment of a less-lethal launcher: the case of the FN 303 ® in a high-pressure setting. ERGONOMICS 2019; 62:1162-1174. [PMID: 31151364 DOI: 10.1080/00140139.2019.1626916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Abstract
The present study explored the usability of a less-lethal launcher from the end-user's perspective. A within-subjects field experiment (N = 16) tested the FN 303® in a lab condition, enabling optimal firing conditions and in a high-pressure simulated operational condition (SOC). Results showed that the high-pressure SOC, which was both psychologically and physiologically challenging, provoked significantly more subjective workload and substantial increases in cortisol biomarker secretion. Importantly, the SOC had a deleterious effect on participants' shooting accuracy at a static target at 30 m. Moreover, as might be expected, accuracy was affected, notably in the hazardous vertical y-axis. Finally, the SOC significantly influenced participants' perception of the overall usability of the FN 303®. These findings, combined with reduced accuracy, could become critical factors during real-life crowd control operations. To the authors' knowledge, no empirical work has tested less-lethal launchers from an end-user's perspective. Recommendations are made with regard to the selection, training, skill maintenance, and design.
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Affiliation(s)
| | - Joel Suss
- b Department of Psychology, Wichita State University , Wichita , KS , USA
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Di Nota PM, Huhta JM. Complex Motor Learning and Police Training: Applied, Cognitive, and Clinical Perspectives. Front Psychol 2019; 10:1797. [PMID: 31440184 PMCID: PMC6692711 DOI: 10.3389/fpsyg.2019.01797] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/19/2019] [Indexed: 01/13/2023] Open
Abstract
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).
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Affiliation(s)
- Paula M Di Nota
- Department of Psychology, University of Toronto, Mississauga, ON, Canada.,Office of Applied Research & Graduate Studies, Justice Institute of British Columbia, New Westminster, BC, Canada
| | - Juha-Matti Huhta
- Police University College, Tampere, Finland.,Faculty of Education, University of Tampere, Tampere, Finland
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10
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Arble E, Daugherty AM, Arnetz B. Differential Effects of Physiological Arousal Following Acute Stress on Police Officer Performance in a Simulated Critical Incident. Front Psychol 2019; 10:759. [PMID: 31024398 PMCID: PMC6465322 DOI: 10.3389/fpsyg.2019.00759] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 03/19/2019] [Indexed: 01/12/2023] Open
Abstract
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.
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Affiliation(s)
- Eamonn Arble
- Department of Psychology, Eastern Michigan University, Ypsilanti, MI, United States
| | - Ana M Daugherty
- Department of Psychology, Wayne State University, Detroit, MI, United States.,Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI, United States.,Institute of Gerontology, Wayne State University, Detroit, MI, United States
| | - Bengt Arnetz
- Department of Family Medicine, College of Human Medicine, Michigan State University, East Lansing, MI, United States
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Sazma MA, McCullough AM, Shields GS, Yonelinas AP. Using acute stress to improve episodic memory: The critical role of contextual binding. Neurobiol Learn Mem 2019; 158:1-8. [DOI: 10.1016/j.nlm.2019.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 12/18/2018] [Accepted: 01/01/2019] [Indexed: 11/27/2022]
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Vartanian O, Fraser B, Saunders D, Suurd Ralph C, Lieberman HR, Morgan CA, Cheung B. Changes in mood, fatigue, sleep, cognitive performance and stress hormones among instructors conducting stressful military captivity survival training. Physiol Behav 2018; 194:137-143. [PMID: 29752975 DOI: 10.1016/j.physbeh.2018.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/27/2018] [Accepted: 05/09/2018] [Indexed: 11/25/2022]
Abstract
Numerous studies have examined the effects of captivity survival training on psychological and physiological function in trainees. In the present study we shifted the focus to instructors, and measured the effects that the delivery of training exerts on their levels of stress and performance. Because instructors are called upon to perform difficult duties (e.g., mock interrogations) under extreme conditions, we hypothesized that significant increases in psychological and physiological indices of stress would occur due to training. In addition, as part of their job tasking, the instructors conducted courses in consecutive weeks. This offered a unique and ecologically valid opportunity to assess carryover of stress from one week to the next. We hypothesized stress levels would be higher in the second than the first week of training. Our first hypothesis was supported: Delivering training was associated with impairments in mood, fatigue, and sleep, as well as a reduction in the ratio of testosterone/cortisol level in blood. Our second hypothesis was largely not supported as a 3-day break separating consecutive courses appeared sufficient for restoring psychological and physiological function. Our results demonstrate that although the delivery of training exerts negative effects on instructors' levels of stress, the 3-day recovery period separating consecutive courses is sufficient to return psychological and physiological function to baseline levels.
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Affiliation(s)
- Oshin Vartanian
- Defence Research and Development Canada, Toronto Research Centre, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada.
| | - Brenda Fraser
- Defence Research and Development Canada, Toronto Research Centre, Toronto, ON, Canada
| | - Doug Saunders
- Defence Research and Development Canada, Toronto Research Centre, Toronto, ON, Canada
| | - Cindy Suurd Ralph
- Director General Military Personnel Research and Analysis, Department of National Defence, Ottawa, ON, Canada; Queen's University, Kingston, ON, Canada
| | - Harris R Lieberman
- U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States
| | - Charles A Morgan
- Yale University School of Medicine, New Haven, CT, United States; Henry C. Lee College of Criminal Justice & Forensic Sciences, University of New Haven, CT, United States
| | - Bob Cheung
- Defence Research and Development Canada, Toronto Research Centre, Toronto, ON, Canada
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Shields GS, Sazma MA, McCullough AM, Yonelinas AP. The effects of acute stress on episodic memory: A meta-analysis and integrative review. Psychol Bull 2017; 143:636-675. [PMID: 28368148 DOI: 10.1037/bul0000100] [Citation(s) in RCA: 248] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A growing body of research has indicated that acute stress can critically impact memory. However, there are a number of inconsistencies in the literature, and important questions remain regarding the conditions under which stress effects emerge as well as basic questions about how stress impacts different phases of memory. In this meta-analysis, we examined 113 independent studies in humans with 6,216 participants that explored effects of stress on encoding, postencoding, retrieval, or postreactivation phases of episodic memory. The results indicated that when stress occurred prior to or during encoding it impaired memory, unless both the delay between the stressor and encoding was very short and the study materials were directly related to the stressor, in which case stress improved encoding. In contrast, postencoding stress improved memory unless the stressor occurred in a different physical context than the study materials. When stress occurred just prior to or during retrieval, memory was impaired, and these effects were larger for emotionally valenced materials than neutral materials. Although stress consistently increased cortisol, the magnitude of the cortisol response was not related to the effects of stress on memory. Nonetheless, the effects of stress on memory were generally reduced in magnitude for women taking hormonal contraceptives. These analyses indicate that stress disrupts some episodic memory processes while enhancing others, and that the effects of stress are modulated by a number of critical factors. These results provide important constraints on current theories of stress and memory, and point to new questions for future research. (PsycINFO Database Record
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14
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Evaluating the Effects of Stress and Fatigue on Police Officer Response and Recall: A Challenge for Research, Training, Practice and Policy. JOURNAL OF APPLIED RESEARCH IN MEMORY AND COGNITION 2016. [DOI: 10.1016/j.jarmac.2016.07.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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15
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ALFF Value in Right Parahippocampal Gyrus Acts as a Potential Marker Monitoring Amyotrophic Lateral Sclerosis Progression: a Neuropsychological, Voxel-Based Morphometry, and Resting-State Functional MRI Study. J Mol Neurosci 2015; 57:106-13. [DOI: 10.1007/s12031-015-0583-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/18/2015] [Indexed: 10/23/2022]
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16
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Meziab O, Kirby KA, Williams B, Yaffe K, Byers AL, Barnes DE. Prisoner of war status, posttraumatic stress disorder, and dementia in older veterans. Alzheimers Dement 2015; 10:S236-41. [PMID: 24924674 DOI: 10.1016/j.jalz.2014.04.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND It is not known whether prisoners of war (POWs) are more likely to develop dementia independently of the effects of posttraumatic stress disorder (PTSD). METHODS We performed a retrospective cohort study in 182,879 U.S. veterans age 55 years and older, and examined associations between POW status and PTSD at baseline (October 1, 2000-September 30, 2003), and incident dementia during follow-up (October 1, 2003-September 30, 2012). RESULTS A total of 484 veterans (0.3%) reported being POWs, of whom 150 (31.0%) also had PTSD. After adjusting for demographics, medical and psychiatric comorbidities, period of service, and the competing risk of death, the risk of dementia was increased in veterans who were POWs only (hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.30-1.98) or had PTSD only (HR, 1.52; 95% CI, 1.41-1.64) and was greatest in veterans who were POWs and also had PTSD (HR, 2.24; 95% CI, 1.72-2.92). CONCLUSIONS POW status and PTSD increase risk of dementia in an independent, additive manner in older veterans.
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Affiliation(s)
- Omar Meziab
- School of Medicine, University of Arizona, Tucson, AZ, USA
| | - Katharine A Kirby
- Division of Geriatrics, Department of Medicine, University of California, San Francisco, CA, USA; San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Brie Williams
- Division of Geriatrics, Department of Medicine, University of California, San Francisco, CA, USA; San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
| | - Kristine Yaffe
- San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, CA, USA; Department of Epidemiology & Biostatistics, University of California, San Francisco, CA, USA
| | - Amy L Byers
- San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, CA, USA
| | - Deborah E Barnes
- San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, CA, USA; Department of Epidemiology & Biostatistics, University of California, San Francisco, CA, USA.
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17
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Phillips C, Baktir MA, Srivatsan M, Salehi A. Neuroprotective effects of physical activity on the brain: a closer look at trophic factor signaling. Front Cell Neurosci 2014; 8:170. [PMID: 24999318 PMCID: PMC4064707 DOI: 10.3389/fncel.2014.00170] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/02/2014] [Indexed: 12/18/2022] Open
Abstract
While the relationship between increased physical activity and cognitive ability has been conjectured for centuries, only recently have the mechanisms underlying this relationship began to emerge. Convergent evidence suggests that physical activity offers an affordable and effective method to improve cognitive function in all ages, particularly the elderly who are most vulnerable to neurodegenerative disorders. In addition to improving cardiac and immune function, physical activity alters trophic factor signaling and, in turn, neuronal function and structure in areas critical for cognition. Sustained exercise plays a role in modulating anti-inflammatory effects and may play a role in preserving cognitive function in aging and neuropathological conditions. Moreover, recent evidence suggests that myokines released by exercising muscles affect the expression of brain-derived neurotrophic factor synthesis in the dentate gyrus of the hippocampus, a finding that could lead to the identification of new and therapeutically important mediating factors. Given the growing number of individuals with cognitive impairments worldwide, a better understanding of how these factors contribute to cognition is imperative, and constitutes an important first step toward developing non-pharmacological therapeutic strategies to improve cognition in vulnerable populations.
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Affiliation(s)
- Cristy Phillips
- Department of Physical Therapy, Arkansas State University Jonesboro, AR, USA
| | - Mehmet Akif Baktir
- Department of Physiology, Erciyes University Kayseri, Turkey; Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Malathi Srivatsan
- Department of Biological Sciences, Arkansas State University Jonesboro, AR, USA
| | - Ahmad Salehi
- VA Palo Alto Health Care System Palo Alto, CA, USA
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18
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Nanda B, Balde J, Manjunatha S. The Acute Effects of a Single Bout of Moderate-intensity Aerobic Exercise on Cognitive Functions in Healthy Adult Males. J Clin Diagn Res 2013; 7:1883-5. [PMID: 24179888 DOI: 10.7860/jcdr/2013/5855.3341] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 05/30/2013] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Single acute bouts of moderately-intense aerobic exercise like walking have been found to improve cognitive control of attention in children, but some studies have reported no improvement in cognitive flexibility following acute aerobic exercise. Submaximal aerobic exercise performed for 60 minutes facilitated specific aspects of information processing in adults but extended exercises leading to dehydration compromised both information processing and memory functions. Improvement in executive functions has also been reported during cycling at 70% of Heart Rate Reserve (HRR) across young and older age groups. However, there are studies which have reported no correlation between physical activity and academic performance in children and a recent systematic review of 30 relevant studies reported no significant improvement in cognition with physical activity or exercise in adults. There seems to be lack of consensus on the effect of exercise on cognition, which may be because the exercise protocols used and cognitive functions tested by different researchers were not uniform. AIM The primary aim of this study was to investigate the acute effects of aerobic exercise across different cognitive domains in healthy young individuals. METHODS A homogeneous group of 10 right handed healthy adult males participated in the study and was subjected to 8 cognitive function tests including 2 tests each across the four categories: Memory, Reasoning, Concentration and Planning using a pre-validated web based tool. Following baseline testing, subjects performed 30 minutes' of cycling on a stationary bicycle ergometer at moderate intensity (60-70% of HRR). Post-test scores were recorded when heart rate returned to within 10% of baseline. Pre and post-test scores were compared using the paired t-test. RESULTS After exercise, there was significant improvement (Mean ± SD) in the Paired Associates (4.8±1.0 Vs 5.5 ± 1.0), Odd One Out (10.5 ± 3.0 Vs 13 ± 3.1) and Spatial Slider test (30.4 ± 17.8 Vs 40.5 ± 13.9), the tests of Memory, Reasoning and Planning respectively. No significant improvement was found for concentration. Total post-test time was significantly lower than the pre-test time (23.5 ± 2.55 Vs 21.2 ± 1.48 minutes). CONCLUSION A single bout of moderate intensity aerobic exercise for as less as 30 minutes can improve some aspects of cognition, most prominently for memory, reasoning and planning and can shorten the time taken to complete the tests.
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Affiliation(s)
- Bijli Nanda
- Assistant Professor, Department of Physiology, School of Medical Sciences and Research Sharda University , Greater Noida, UP, India
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Meyer T, Smeets T, Giesbrecht T, Quaedflieg CWEM, Merckelbach H. Acute stress differentially affects spatial configuration learning in high and low cortisol-responding healthy adults. Eur J Psychotraumatol 2013; 4:19854. [PMID: 23671762 PMCID: PMC3644058 DOI: 10.3402/ejpt.v4i0.19854] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 12/12/2012] [Accepted: 12/15/2012] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Stress and stress hormones modulate memory formation in various ways that are relevant to our understanding of stress-related psychopathology, such as posttraumatic stress disorder (PTSD). Particular relevance is attributed to efficient memory formation sustained by the hippocampus and parahippocampus. This process is thought to reduce the occurrence of intrusions and flashbacks following trauma, but may be negatively affected by acute stress. Moreover, recent evidence suggests that the efficiency of visuo-spatial processing and learning based on the hippocampal area is related to PTSD symptoms. OBJECTIVE The current study investigated the effect of acute stress on spatial configuration learning using a spatial contextual cueing task (SCCT) known to heavily rely on structures in the parahippocampus. METHOD Acute stress was induced by subjecting participants (N = 34) to the Maastricht Acute Stress Test (MAST). Following a counterbalanced within-subject approach, the effects of stress and the ensuing hormonal (i.e., cortisol) activity on subsequent SCCT performance were compared to SCCT performance following a no-stress control condition. RESULTS Acute stress did not impact SCCT learning overall, but opposing effects emerged for high versus low cortisol responders to the MAST. Learning scores following stress were reduced in low cortisol responders, while high cortisol-responding participants showed improved learning. CONCLUSIONS The effects of stress on spatial configuration learning were moderated by the magnitude of endogenous cortisol secretion. These findings suggest a possible mechanism by which cortisol responses serve an adaptive function during stress and trauma, and this may prove to be a promising route for future research in this area.
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Affiliation(s)
- Thomas Meyer
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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