Physiological Measures of Arousal During Soldier-Relevant Tasks Performed in a Simulated Environment

Deployed United States Army Soldiers operate in dynamic situations, yet there is little known about how to most effectively train Soldier combat skills in a stress-inducing environment prior to deployment. In order to best simulate the experiences of Soldiers in theater, a training environment must be immersive, creating the illusion of "being there," thus providing a heightened level of arousal and encouraging the desire to perform well within the training. A 300-degree immersive simulator was used to examine the potential effectiveness of such a training environment. Participants performed a Shoot-Don't-Shoot task with two types of performance feedback, shock and lifebar loss Levels of arousal were continuously measured through heart rate variability HRV; psychophysiological measures have been linked to psychological stress and cognitive function. HRV was measured through interbeat interval IBI, or the peak-to-peak interval of heartbeats, which is linked to cognitive arousal. Higher levels of arousal were seen in the Shock condition compared to the Life Bar condition. IBI was additionally examined in a Baseline session as well as Post-Shock and Post-Life Bar sessions, and results showed that IBI returned to near Baseline levels after both conditions, indicating a recovery from arousal induced during the scenarios. These results show the value of objectively measuring physiology to assess heightened arousal during Soldier-relevant tasks in a simulated environment. Examining the extent to which Soldiers experience arousal, which can often be a proxy for stress, can indicate how immersive or stressful an environment is, and therefore its potential effectiveness as a realistic pre-deployment training environment.

[1]  Debbie Patton,et al.  How Real Is Good Enough? Assessing Realism of Presence in Simulations and Its Effects on Decision Making , 2014, HCI.

[2]  Joanna Bugajska,et al.  Heart rate variability (HRV) during virtual reality immersion , 2015, International journal of occupational safety and ergonomics : JOSE.

[3]  Y. Stern,et al.  Inter- and intraindividual variability in recognition memory: effects of aging and estrogen use. , 2004, Neuropsychology.

[4]  R. Yerkes,et al.  The relation of strength of stimulus to rapidity of habit‐formation , 1908 .

[5]  John T. Cacioppo,et al.  Heart Rate Variability: Stress and Psychiatric Conditions , 2007 .

[6]  H. Nagaraja,et al.  Heart rate variability: origins, methods, and interpretive caveats. , 1997, Psychophysiology.

[7]  G. Breithardt,et al.  Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. , 1996 .

[8]  B. Oken,et al.  Sensitivity to mental effort and test–retest reliability of heart rate variability measures in healthy seniors , 2011, Clinical Neurophysiology.

[9]  E. Volchan,et al.  Resilience and vagal tone predict cardiac recovery from acute social stress , 2007, Stress.

[10]  Marcus K. Taylor,et al.  Neurophysiologic methods to measure stress during survival, evasion, resistance, and escape training. , 2007, Aviation, space, and environmental medicine.

[11]  Michael Meehan,et al.  Physiological measures of presence in stressful virtual environments , 2002, SIGGRAPH.

[12]  N. Alessi,et al.  Presence as an emotional experience. , 1999, Studies in health technology and informatics.

[13]  Vinod Kumar,et al.  Cognitive Behavior Evaluation Based on Physiological Parameters among Young Healthy Subjects with Yoga as Intervention , 2015, Comput. Math. Methods Medicine.

[14]  S. Huffel,et al.  Instantaneous changes in heart rate regulation due to mental load in simulated office work , 2011, European Journal of Applied Physiology.

[15]  S. MacDonald,et al.  Intra-individual variability in behavior: links to brain structure, neurotransmission and neuronal activity , 2006, Trends in Neurosciences.

[16]  F. Booth,et al.  Lifetime sedentary living accelerates some aspects of secondary aging. , 2011, Journal of applied physiology.

[17]  M. Malik.  Heart Rate Variability , 1996, Clinical cardiology.

[18]  D. Swain,et al.  Autonomic Response to Tactical Pistol Performance Measured by Heart Rate Variability , 2015, Journal of strength and conditioning research.

[19]  D. Fowles,et al.  The three arousal model: implications of gray's two-factor learning theory for heart rate, electrodermal activity, and psychopathy. , 1980, Psychophysiology.

[20]  Heart Rate Variability Response to Stressful Event in Healthy Subjects , 2009 .

[21]  S. Folkman,et al.  Stress, Appraisal, and Coping. New York, NY: Springer; , 1984 .

[22]  Christopher R. Johnson,et al.  Aerobic fitness and intra-individual variability of neurocognition in preadolescent children , 2013, Brain and Cognition.

[23]  M. Hotta,et al.  Psychological stress increases arousal through brain corticotropin-releasing hormone without significant increase in adrenocorticotropin and catecholamine secretion , 1993, Brain Research.

[24]  L. Luecken,et al.  Measuring Task-related Changes in Heart Rate Variability , 2007, 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[25]  Gert Pfurtscheller,et al.  Analysis of Physiological Responses to a Social Situation in an Immersive Virtual Environment , 2006, PRESENCE: Teleoperators and Virtual Environments.