Towards user-adapted training paradigms: physiological responses to physical threat during cognitive task performance

Feedback of physiological responses have a great potential to support virtual training paradigms aimed to increase cognitive task performance under stressful threatening conditions. In the current study, we examined the sensitivity of a range of physiological indicators derived from electrodermal activity (EDA), blood pressure (BP) and heart rate (HR) to measure stress as induced by the threat of an electric shock (ES). In contrast to previous work that studied physiological stress responses compared to a rest condition, we compared conditions with high cognitive load combined with stress caused by threat of an ES, to conditions with high cognitive load without such stress. Twenty-five participants performed a cognitively demanding task in an experimental setup. At certain 10 s time intervals, indicated by a continuous tone, participants were either asked to do their best and increase cognitive task performance (non-threat condition), or they were told that they could receive an ES during this interval if cognitive task performance was not high enough (threat condition). Physiological measures, task performance and self-reported measures of stress and workload were analysed. Task performance and self-reported measures of stress and workload were roughly the same in both conditions. Especially EDA measures were affected by the threat of an ES. Threat and non-threat conditions could be distinguished with an across-participant classifier using EDA and BP features with an accuracy of 70%. These results suggest that EDA and BP can be used to evaluate stress coping training paradigms or to individually adapt the stress levels in virtual training environments.Stress-related psychiatric disorders across the life spa

Negative instructions and choking under pressure in aiming at a far target

Providing instructions to avoid an action may ironically increase the tendency to engage in that action, especially when attentional resources are taxed. In the perceptual-motor domain the role of anxiety in inducing such ironic effects has rarely been investigated even though anxiety both affects attention and plays a crucial role in performance decrements in sports (i.e., choking under pressure). Therefore, we investigated the combined effects of anxiety and negative instructions on perceptual-motor performance. Participants threw darts under one neutral instruction to hit bulls-eye and one negatively worded instruction while positioned either high or low on a climbing wall (i.e., with and without anxiety). Only the combination of high anxiety and the negative instruction led to a significant drop in performance. In line with theories on ironic processes and choking, the results indicate that when negative instructions and anxiety are combined, the likelihood of ironic effects and, thus, choking, is increased

Ironic effects and final target fixation in a penalty shooting task

The aim of the present study was to find out whether ironic effects in a far aiming task were accompanied by shorter final fixations on the target. Generally, it is well known that a sufficiently long final fixation on the target is of crucial importance for accurate performance in far aiming. Recently, it has been shown that ironic effects in golf putts and penalty kicks (in which one does the opposite of what was intended, e.g., shoot close to the keeper while attempting to avoid this) were preceded by longer fixations on the to-be-avoided area, which may have resulted in shorter final fixations on the target area. Therefore, in the current study we examined football players taking penalties in a simulated penalty environment with and without instructions to avoid the goalkeeper. The findings revealed that ironic effects were indeed accompanied by significantly shorter final fixations on the target area, i.e., the open goal space. It is concluded that in far aiming tasks, ironic effects are accompanied by insufficiently long final fixations on the target. © 2010 Elsevier B.V

Testing the applicability of a virtual reality simulation platform for stress training of first responders

The current study explores whether different stressors in a virtual reality (VR) military training scenario cause increases in physiological stress. This would validate the use of VR simulation for stress training, as well as the physiological monitoring of trainees for educational purposes. Military cadets (n = 63) performed a patrol scenario (military convoy) in which they answered questions about their surroundings. Stressors (task difficulty, noise, lighting changes, social evaluations, electric muscle stimulation, and a simulated attack on the convoy) were stepwise added in four phases. Electrocardiogram, blood pressure, electrodermal activity, cortisol, and the cadets' subjective threat/challenge appraisal were measured. We found that only the first phase caused a significant increase in physiological stress, as measured with heart rate, heart rate variability, and electrodermal activity. Physiological stress appeared to stay high in the second phase as well, but decreased to baseline level in the third and fourth phases, even though these phases were designed to be the most stressful. Cadets classified as threat responders based on physiological data (n = 3) scored significantly higher on subjective threat/challenge appraisal than those classified as challenge responders (n = 21). It seems that in the tested VR training scenario, the novelty of the scenario was the only effective stress stimuli, whereas the other implemented stressors did not cause a measurable physiological response. We conclude that if VR training scenarios are to be used for stress training, these should confront trainees with unpredictable but context-specific demands.Stress-related psychiatric disorders across the life spa