Training in a deliberately distracting environment
Stress exposure training is the practicing of important existing skills in a stressful and distracting environment to develop the ability to perform them reliably in spite of the circumstances.
There are a number of occupations where a potentially high-stress, high-risk environment can occur, where failure to act appropriately can lead to injury, death or significant loss. These settings can be found in military engagements, aviation, emergency medicine, mining, underwater diving, parachuting, bomb disposal, police work, and fire fighting. These environments impose a high demand on those who work in them, and there is a high potential for immediate and often catastrophic harm following an error. Emergency or crisis conditions can occur suddenly and without warning.
The effects of stress on the individual are a concern in industry, the military, aviation, sports, and other settings where effective performance under stress is required. In this context, stress is a process by which environmental demands result in a perception that demand exceeds resources. This can have negative physiological, psychological, behavioral, or social effects, by restricting attention and distracting the operator from the primary task. Technical skill is a necessary but not always a sufficient condition for effective performance in a stressful environment. Effective training to reduce the negative effects of stress on performance has become important in the training community. The purpose of stress exposure training is to prepare people to function effectively under high-stress conditions.
The main purpose of "training" is to develop and retain skills, knowledge, understanding and abilities, and most training is occurs in conditions which facilitate learning. These conditions usually involve an environment which is free of avoidable discomfort, surprises, and other distractions, allowing focused concentration on understanding and mastering the components and combinations of skills. This is generally effective when performance will be under similar circumstances, but when transferred to stressful operational conditions, reliable performance is not guaranteed.
The main purpose of "stress training" is to prepare the person to perform effectively in a high-stress environment. It increases familiarity with the environment and conditions in which the skills must be performed effectively, and develops the ability and confidence to perform those skills in spite of the distractions and task loading present.
Effects of stress on performance.
Stress is recognised as adversely altering cognitive processes such as attention, memory, and making decisions. High task loads and time pressures tend to cause narrowing of attention and loss of team perspective. Noise, thermal stress, and fatigue have also been implicated in performance degradation. Adverse environmental conditions can make effective performance physically more difficult at the same time that other distractions occur.
Theories of stress identify at least two aspects to human stress response. The appraisal process includes the person's assessment of a situation to decide whether they have the abilities and resources to cope, and has two stages:
Strategies for managing stress-degraded performance.
Three basic methods exist for counteracting the effects of stress on performance:
Application of the techniques.
Stress-exposure training can be effective as a part of initial training or a part of refresher training, but should not be introduced before the skills are well learned or it can interfere with skill acquisition. If used in refresher training, it should follow an initial exercise and assessment of skills to ensure they are remembered and practiced correctly. It is not necessary or desirable to match the stress levels in the exercises with reality. A lower level of stress can be adequate to accustom the learner while less likely to cause a negative learning experience, but the simulations should be relevant and the situations reasonably realistic. A gradual buildup may have good results. Where stress training is optional or voluntary, a gradual buildup will allow learners to continue as far as they feel they are able to manage.
Experimental findings show that technical skill is a necessary but not always a sufficient condition for effective performance in a stressful environment, and that skills learned from stress training generalise to different tasks and stressors.
Familiarity with the stressors characteristic of the occupation is needed in order to reduce uncertainty and to improve effectiveness of learning.
Effectiveness.
Analyses have indicated that the training is most effective with high- or normal anxiety individuals, and effectiveness is partly proportional to the number of training sessions. Four to seven sessions were needed to produce significant improvements in performance and anxiety levels. 
The training approach including all three stages has been shown to be most effective, with the skills training phase most important, and the training remains effective when unfamiliar stressors are applied. The training was also effective in preparing participants to perform tasks that had not been practiced under stress, and appears to be useful for people who may have to perform under unpredictable conditions. 
References.
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