Journal of Human Performance in Extreme Environments

Changes in EEG during Ultralong Running

M. Doppelmayr et al. — Thu, 18 Oct 2012 08:40:49 PDT

There are only a few studies using human electroencephalograms (EEGs) to investigate bioelectrical changes in the brain during exercise (running or cycling). These studies report an increase in EEG alpha amplitude during and immediately after exercise. However, only exercises within a relatively short time interval of approximately 1 hour have been investigated. Thus, we focussed on long-lasting exercise and report three single case studies, performed on the same participant, during extended exercise and under different thermal conditions. EEG was recorded during a 12-, 24-, and 56-hour ultramarathon. The 56-hour race was performed under extreme thermal stress in Death Valley, CA, with temperatures well above 55uC/131uF. Analyzing the centre gravity frequency of the EEG alpha rhythm yielded a gradual decrease with time for the 12- and 24-hour races. In the 56-hour race, the centre frequency decreased only until the first sleeping period. Alpha amplitude, on the other hand, did not vary systematically. For all three races, the lowest alpha amplitude was observed during the last test session. This decrease is most likely due to cognitive and emotional changes but not to thermal stress, exhaustion, or sleep deprivation.

Perceived Motion Sickness and Effects on Performance Following Naval Transportation

Joakim Dahlman et al. — Thu, 18 Oct 2012 08:31:04 PDT

The present study focused on the relationship between previous experiences of, and rated susceptibility to, motion sickness and its correlation to subjective measurements and actual performance. Performance was measured in terms of shooting precision among 23 participants from the Swedish amphibious corps after transportation in a small amphibious boat, while sealed off with no reference to the outside world. Self-rating questionnaires were collected regarding perceived performance and presence of motion sickness. The physiological status perceived by each participant was related to factors that generally indicate early stages of motion sickness, which also were correlated to deficits in performance. It was further shown that participants who believed that their performance could be affected by motion sickness also performed less well.

Sleep Disturbance Implications for Modern Military Operations

Douglas R. Lindsay et al. — Fri, 12 Oct 2012 05:50:48 PDT

As is evident from current military operations that are happening around the globe (e.g., Iraq, Afghanistan, Korea), today’s military is being called on in numerous new and innovative ways (e.g., Foster & Lindsay, 2011). One of the primary forces behind this change is the pervasiveness of enhanced information systems. In fact, the concept of networked warfare is the basis of operations and doctrine for the armed forces (Wesensten, Belenky, & Balkin, 2005). With respect to Admiral Cebrowski’s quote, it appears that this notion of information in warfare is going to continue to influence the way that we approach and conduct war for the foreseeable future. While this use of information and information systems have been used successfully in recent operations (Cammons, Tisserand, Williams, Seise, & Lindsay, 2006), it must always be considered with respect to the operational context. This context is made up of the military’s primary weapon system (the individual solider) and the features of the operational environment in which they are expected to perform.

Within the context of current military operations, the individual combatant is experiencing demands never before seen by predecessors. While deployments and warfare are certainly not new to military personnel, expectations regarding the use and processing of information during these operations is at an unprecedented level. These changing expectations regarding information processing have virtually transformed the soldier into a ‘‘cognitive platform’’. While this platform is certainly the most capable the world has ever seen, there are factors which limit this platform’s warfighting capability. These include such factors as nutritional or caloric deficiencies, dehydration, psychological stressors, carrying excessive loads, and hypothermia (Lieberman et al., 2005; Meyerhoff et al., 2000; Wesensten et al., 2005). Another key factor is sleep. While sleep is a basic physiological need that is usually regulated by the individual, in a military environment conditions often dictate how much sleep is obtained (and the quality of that sleep), independent of the individual military member’s personal needs or desires. Somewhat absent, however, is a critical examination of the impact of sleep loss on this "new" cognitive platform in today’s military environment. While some research has been done to address pieces of this issue (Wesensten et al., 2005), there are still many gaps that remain. Therefore, the purpose of this review is to briefly examine what is known about the effects of sleep and predict the implications of restricted sleep and sleep loss in this informationally-enhanced environment. In order to do this, three areas need to be examined in greater detail: the current operational military environment, the amount of sleep required, and sleep loss and its subsequent effects on cognitive functioning and resulting decision making in such an environment. Finally, implications in light of this information and attempts at mitigation are suggested.

Investigating Visual Alerting in Complex Command and Control Environments

Jacquelyn M. Crebolder — Fri, 12 Oct 2012 05:50:47 PDT

A series of experiments was conducted to investigate visual alerting in complex command and control environments, where operators must use several displays to perform tasks. In the first experiment, the speed of detection of two alerts, one in the form of a short bar and the other a border surrounding the perimeter of the display, were compared under flashing and static states. Findings showed that bar alerts were detected faster than border alerts and that adding a flashing attribute did not provide a benefit. The second study monitored which display participants were attending to when the alert appeared, and the results revealed that alert detection was not always superior when alerts and attention were on the same display. The third experiment investigated display configuration to ensure that the previous findings were not a result of the specific tasks performed on each display. The results are discussed in the context of the limitations of spatial attention.

Perceived Motion Sickness and Effects on Shooting Performance Following Combat Vehicle Transportation

Joakim Dahlman et al. — Fri, 12 Oct 2012 05:50:45 PDT

This study used a quasi-experimental, repeated measures design to study the relationship between targeting performance and perceived motion sickness following exposure to motion in a land-based transportation setting. The targeting performances of 22 basic training conscript soldiers were examined after repeatedly being transported in the vehicle. Soldiers also rated their perceived motion sickness according to subjective scales before and after the two exposures to transportation. Results showed that perceived motion sickness was correlated to perceived decrease in targeting performance, due to factors labelled as “Combined subjective symptoms”. The study supports the idea that motion sickness and its effect on performance should be studied by using actual performance measurements as a supplement to subjective ratings.

Factors Influencing Physical Risk Taking in Rock Climbing

Marcus K. Taylor et al. — Fri, 12 Oct 2012 05:50:44 PDT

This study was designed to investigate factors influencing physical risk taking in the sport of rock climbing. Specifically, the relationships between physical risk taking, sensation seeking, spheres of control, and desirability of control were examined. One hundred five rock climbers from the United States completed a series of surveys measuring each of the above-mentioned psychological variables. As predicted, physical risk taking demonstrated significant positive relationships to both total sensation seeking and thrill/adventure seeking (TAS). The expected relationships between physical risk taking, personal control and desirability of control were not supported. As hypothesized, no substantive patterns were revealed between physical risk taking and interpersonal control or sociopolitical control. Finally, comparisons between high and low physical risk taking rock climbers revealed significant group differences for total sensation seeking, TAS, and disinhibition. The identification of predictors of physical risk taking is a key step toward identifying individuals likely to engage in high physical risk behavior, and under what circumstances they are likely to do so.

Motivation in Extreme Environments: A Case Study of Polar Explorer Pen

Juliette C. Lloyd et al. — Fri, 12 Oct 2012 05:50:43 PDT

This study documents the motives of a polar explorer, Pen Hadow, during the period of a 64-day solo expedition in which he skied, without resupply by aircraft, from Canada to the North Geographic Pole. The framework of reversal theory (Apter, 1982) was used to provide a systematic and comprehensive structure for studying such motivation in an extreme environment. Quantitative data were obtained by using the Apter Record of Motivational States. Qualitative data came from interviews structured in terms of reversal theory. The main result was that the explorer needed at different times to call upon all the eight motivational states identified by reversal theory rather than being subject to only the one or two most obvious ones. The telic and autic states were the two that occurred most frequently. Implications for would-be explorers, and for extreme athletes and their coaches, are indicated.

Psychological and Psychophysiological Effects of a High-Mountain Expedition to Tibet

Marcus Stück et al. — Fri, 12 Oct 2012 05:50:41 PDT

In March 1999 a team of 8 mountaineers (6 men and 2 women) climbed up the 6th highest mountain of the world: The Cho Oyo (8201 m), located in the high mountains of Tibet. During the expedition, we investigated the effects of high mountaineering on various psychological variables (e.g., anxiety) and psychophysiological variables (e.g. blood pressure, pulse, skin-resistance) as well as the ability to relax at different points of time (2 premeasures before, three measures during, and one post-measure immediate after the Expedition). Due to a long-term monitoring of the skin resistance, we can summarize that three different adaptation levels can be defined, that appear under increasing pressure: Inhibition of overload, unspecific hypersensibility and exhaustion. The results can show that a telemedical assessment is possible and necessary even under the circumstances of a highmountaineering expedition in order to determine and predict deficits in behaviour and health risks for individuals at high altitudes.

Dynamic Modeling of Crew Performance for Long-Duration Space Missions

Sara Goudarzi et al. — Fri, 12 Oct 2012 05:50:40 PDT

Crew time is one of the most valuable and limited resources during long-duration space missions. Crew time requirements fluctuate depending on variations in crew performance. The limited number of crewmembers, resources, and the myriad of tasks to be performed leave a tight schedule for crewmembers during long-duration space missions. This schedule needs to account for potential interventions (stress events) that may alter predicted performance and thus scheduling. A dynamic crew model using a stochastic Auto Regressive Integrated Moving Average (ARIMA) model of interrupted time series was developed to account for the effects of potential stress events on crew performance. This model aids in estimating crew time requirements for varying mission scenarios and for evaluating stress event effects on crew performance.

Maintaining Privacy During Psychosocial Research on the International Space Station

Jennifer Boyd Ritsher et al. — Fri, 12 Oct 2012 05:50:40 PDT

Conducting psychosocial research on the International Space Station (ISS) requires rigorous privacy precautions that exceed standard scientific human subject protocols. In our previous study involving crewmembers on Mir, and in our ongoing ISS work, special precautions were taken during each phase of the missions. Pre-flight, participants received detailed consent forms explaining that only group-level data would be presented, and they chose ID codes known only to them. In-flight, special procedures protected data during collection and transmission. Post-flight, our analytic strategy further masked participants’ identities, and participant representatives were invited to review manuscript drafts prior to publication. In this paper we describe lessons learned during our on-orbit studies and discuss their relation to maintaining privacy on studies of future long-duration space missions.

Effects of Thermal Stress on Dual Task Performance and Attention Allocation

Bradley Chase et al. — Fri, 12 Oct 2012 05:50:39 PDT

A visual-visual dual task was designed to test the effect of the thermal environment on dual task performance and attention allocation. The temperatures selected for testing were 20 and 35°C Wet Bulb Globe Temperature (WBGT) in experiment 1 and 25, 30 and 35°C Wet Bulb Globe Temperature (WBGT) in experiment 2. In experiment 1, 34 volunteers were randomly assigned to one of the two temperature conditions. A variable representing accuracy on both tasks was coded such that a correct response was assigned only if the participant answered correctly on both tasks. In experiment 2, 42 volunteers were randomly assigned to one of three temperature conditions and instructed vary the amount of attention allocated to each task. Individual differences in single task performance were controlled by equating the baselines of single task performance. Once individual differences in single task capacity were controlled, statistically significant differences in performance were demonstrated. Mean accuracy was computed over a one-hour testing period in each temperature condition. Participants’ mean accuracy in the 35°C condition (38.18%) was substantially less than in the 20°C condition (50.88%). Further, statistically significant differences in performance were detected: in the ability to equally divide attention, effectively allocate attention, and in the relative divided attention cost under thermal stress.

The Adverse Impact of Remote Command and Control under Live Fire

Kip Smith — Fri, 12 Oct 2012 05:50:37 PDT

The US Army is planning a shift in the mode of command and control between soldiers and their battlefield leaders. Soldiers will receive orders from afar through electronic means of communication. This practice is known as remote command and control. Reliance on remote command and control has the potential to erode trust between soldiers and their leaders and should, we hypothesize, slow soldiers' response times to commands to move and to shoot. We have conducted two field experiments to test this hypothesis (Pangburn, Freund, Pangburn, & Smith, 2003). Our laboratory was a paintball assault lane. While a paintball lane is not actual combat, we have found that its live but non-lethal fire makes it an effective and ethical laboratory for studying the behavioral and cognitive effects of stress induced by live fire. Participants were exposed to two conditions of communication mode, leader-present (face to face) and leader-remote (two-way radio). The contrast between participants' response times to commands to move and to shoot was statistically significant and was consistent with the predicted decrement in the remote command-and-control condition.

Mitigating the Negative Effects of Stress in Space Flight: ATransactional Approach

Haydee M. Cuevas — Fri, 12 Oct 2012 05:50:37 PDT

The primary goal of this theoretical paper is to highlight how a transactional approach to investigating stressor effects during space flight can lead to a greater understanding of the complex processes by which humans adapt psychologically and physically to the adverse conditions encountered in this extreme environment.Transactional approaches conceptualize stress as occurring in the nature of the "transaction" (Le., interaction) between the individual and the stimulus environment, emphasizing the role of cognitive appraisal (Le., perceived ability to cope with the situation). Interventions that positively influence this cognitive appraisal process may, therefore, lessen the experience of stress and optimize human performance in space. This paper begins with a theoretical overview of the transactional model, followed by a brief review of several major environmental, physiological, and psychological stress-provoking factors encountered during space flight. The final section discusses interventions, within the context of cognitive appraisal, for selection, training, in-flight support, and design.

The Impact of Simulated Digital Data Radio Communication Induced Interference on Voice Radio Communication Intelligibility

Daniela Kratchounova — Fri, 12 Oct 2012 05:50:36 PDT

Testing to date indicates there is a significant potential for adverse interference from the digital system to the analog system, especially for General Aviation (GA) aircraft. This type of interference can be described as short, random bursts of noise capable of completely obliterating parts of the voice communication. The subsequent degrading effects on voice radio communication could jeopardize flight safety. To address this issue, the goal of the present study was to examine the degree to which such noise impacts voice radio communication intelligibility. Intelligibility was assessed employing a classic, well-established psycho-acoustic method, which uses human beings, rather than electronic test instruments, to assess speech communication systems. The discussion centers on the importance of understanding how interference with speech can degrade human performance directly, by disturbing normal social and work-related activities, and indirectly, by causing annoyance and stress.

Urban Combat: The Ultimate Extreme Environment

Donald R. Lampton et al. — Fri, 12 Oct 2012 05:50:36 PDT

Urban combat is one of the most extreme environments imaginable. Our paper describes training and simulation research to improve the training of small teams that operate on foot in urban combat and stability operations. We present an overview of urban combat as an extreme environment. Next, we trace the history of the training and technology developments that shaped our present research. The focus of our paper is the After Action Review (AAR) process as applied to small team exercises conducted in immersive virtual environments. A PC-based AAR system is described and examples are given of its use for training and training research. The training emphasizes practice of command and control skills, decision making, and situation awareness. Future research goals are outlined. Current live training capabilities are described to provide a context of the overall training environment with which virtual training systems will be integrated.

Assessment of Real Data and Theoretical Issues in Extreme Aviation Environments

Peter I. Terrence et al. — Fri, 12 Oct 2012 05:50:35 PDT

We investigated performance in extreme aviation situations using data recorded from actual in-flight emergencies that resulted in an accident. Response times to such sounds as alarms, auditory cues, and critical verbal statements were extracted from cockpit voice recorder (CYR) transcripts. Preliminary screening identified 14 CYR transcripts which permitted response time evaluation. Results from these selections showed crewmember response times ranging from 1 second to 41 seconds, with a mean and standard deviation of 9.57 s and 10.56 s, respectively. Despite the evident problems of sample size resulting in a positively skewed distribution and the limitations on the inferences drawn from these results, we contend that these data render insights into actual emergency response performance and point to valuable avenues for future exploration.

Evaluating Human Performance and Advanced Technology Design in Extreme Environments

J. Christopher Brill et al. — Fri, 12 Oct 2012 05:50:34 PDT

Evaluating human performance in extreme environments offers unique challenges to human factors practitioners, researchers, and designers. Existing methodologies do not facilitate making cross-modal comparisons of cognitive-attentional demand levels. The present paper describes a multi-sensory protocol device for the evaluation of workload when assessing human performance and the differential demands placed upon sensory modalities.

Supporting Decision-Making in the Battlefield: Utility of Multimedia Information Transmission

Sandro Scielzo et al. — Fri, 12 Oct 2012 05:50:34 PDT

In the theatre of war, environmental and workload factors (e.g., noise, time pressure) may dramatically overburden operator's cognitive processes. Well designed multimedia technology can successfully minimize both intrinsic (working memory capacity) and extrinsic (inefficient use of information) sources of cognitive load, thereby facilitating the decision-making process. These positive mediating effects of multimedia technology can occur during three distinct phases of human information processing: 1) during sensorial information acquisition, by filtering out unnecessary environmental noise and transferring information via context-dependent modalities; 2) during decision-making, by making critical task-relevant cues more salient; and 3) following response execution, by providing necessary feedback to effectively evaluate the appropriateness of the decision taken. After analyzing the dramatic events that led to many US soldier casualties in a Somali rescue mission, this paper will propose a set of recommendations to help future task forces in urban environments, and to specify the greater goal of multimedia use on the battlefield.

Comparison of Simulated High Altitude Pilot Effective Performance Time Between Habitual Smokers and Non-Smokers

James F. Fletcher — Fri, 12 Oct 2012 05:50:33 PDT

Smoking attenuates the amount of oxygen that diffuses from the lung tissue and oxygenates the blood (Guyton, 1996). High altitudes attenuate the oxygen available for transport to the blood. However, little has been reported on the combined effects of these two forms of hypoxia (inadequate oxygenation of the blood). It may be that, together, these two hypoxic conditions react exponentially to critically affect human performance. Fifty-two participants were screened for cotinine serum values >200 ng/dl-1 , to flesh out nicotine usage, through urine sampling. Nineteen participants were entered into the smoker's group and 33 into the non-smoker's group. All of the participants were active student pilots. All of them held current instrument ratings and all of them had approximately the same amount of time and experience in instrument meteorological conditions (IMC). Data were analyzed using Microsoft Excel and SPSS computer software statistic programs. The criterion for significance (alpha) was set at 0.05. The test was a non-directional t-test (two-tailed), which means that an effect in either direction was interpreted. Statistical significance existed when comparing the mean effective performance times between smoking pilots and nonsmoking pilots t = 3.541 (39), p = .05 in the experimental (simulated altitude) groups. Within the limitations of this study it can be concluded that the combined hypoxic effects of smoking and high altitude result in a statistically significant detriment in pilot effective performance time.

A Research Agenda for the United States Coast Guard

Krystal A. Bradley et al. — Fri, 12 Oct 2012 05:50:33 PDT

Historically, the United States Coast Guard has not been widely recognized as an armed force relative to those branches housed under the Department of Defense. However, the country's implementation of the Department of Homeland Security (DHS) has resulted in an increased awareness of the Coast Guard as a critical agency in the country's line of defense. In large part, this change has occurred because the Coast Guard has been incorporated as a part of DHS while previously the agency was housed under the Department of Transportation. Consequently, many problems relating to the day to day operations of the Coast Guard have received relatively little of researchers' attention. Therefore, there is a need to identify critical issues faced by the members of the Coast Guard. Toward this end, the current paper identifies areas of needed research and provides suggestions for ways they might be addressed by research psychologists.