title: Cognitive function, stress hormones, heart rate and nutritional status during simulated captivity in military survival training.
abstract: Stress influences numerous psychological and physiological processes, and its effects have practical implications in a variety of professions and real-world activities. However, few studies have concurrently assessed multiple behavioral, hormonal, nutritional and heart-rate responses of humans to acute, severe stress. This investigation simultaneously assessed cognitive, affective, hormonal, and heart-rate responses induced by an intensely stressful real-world environment designed to simulate wartime captivity. Sixty males were evaluated during and immediately following participation in U.S. Army Survival, Evasion, Resistance, and Escape (SERE) school, three weeks of intense but standardized training for Soldiers at risk of capture. Simulated captivity and intense mock interrogations degraded grammatical reasoning (p<0.005), sustained-attention (p<0.001), working memory (p<0.05) and all aspects of mood assessed by the Profile of Mood States (POMS) questionnaire: Tension/Anxiety, Depression/Dejection, Anger/Hostility, Vigor/Activity, Fatigue/Inertia; Confusion/Bewilderment, and Total Mood Disturbance (p<0.001) It also elevated heart rate (p<0.001); increased serum and salivary cortisol and dehydroepiandrosterone-sulfate (DHEA-s) (p<0.01); elevated serum epinephrine, norepinephrine, and soluble transferrin receptors (sTfR) (p<0.01); increased salivary neuropeptide-Y (NPY) (p<0.001); and decreased serum prolactin and serum and salivary testosterone (p<0.001). Partial recovery was observed immediately after training, but stress-induced changes, particularly in body weight and several of the biomarkers, persisted. This study demonstrates that when individuals were exposed to realistic and controlled simulated captivity, cognition, mood, stress hormones, nutritional status and heart rate are simultaneously altered, and each of these subsequently recovers at different rates.
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA. Electronic address: harris.r.lieberman.civ@mail.mil.
authors.forename: Harris R
authors.initials: HR
authors.lastname: Lieberman
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; Oak Ridge Institute for Science and Education, Belcamp, MD 21017, USA.
authors.forename: Emily K
authors.initials: EK
authors.lastname: Farina
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; Oak Ridge Institute for Science and Education, Belcamp, MD 21017, USA.
authors.forename: John
authors.initials: J
authors.lastname: Caldwell
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; Oak Ridge Institute for Science and Education, Belcamp, MD 21017, USA.
authors.forename: Kelly W
authors.initials: KW
authors.lastname: Williams
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; Oak Ridge Institute for Science and Education, Belcamp, MD 21017, USA.
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Thompson
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Niro
authors.affiliation: John F. Kennedy Special Warfare Center and School, U.S. Army Special Operations Command (USASOC), Fort Bragg, NC 28310, USA.
authors.forename: Kyle A
authors.initials: KA
authors.lastname: Grohmann
authors.affiliation: Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
authors.forename: James P
authors.initials: JP
authors.lastname: McClung
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001835:Body Weight; D003071:Cognition / Q000502:physiology*; D005221:Fatigue / Q000209:etiology / Q000378:metabolism / Q000523:psychology; D006339:Heart Rate / Q000502:physiology*; D006728:Hormones / Q000378:metabolism; D006801:Humans; D008297:Male; D008889:Military Personnel / Q000523:psychology*; D009752:Nutritional Status / Q000502:physiology*; D063906:Prisoners of War / Q000523:psychology*; D020127:Recovery of Function; D000066908:Simulation Training; D013315:Stress, Psychological / Q000378:metabolism*; D014481:United States; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006728:Hormones
keywords: Fatigue; Mood; N-back task; Psychomotor vigilance (PVT); SERE school