Information Processing Changes following Extended Stress

Extended periods of stress are associated with subjective fatigue and performance deterioration. Psychological state and cognitive performance were assessed before and after one week of field training at a Navy Survival, Evasion, Resistance and Escape School. Subjective discomfort increased, but average cognitive performance deterioration was limited to increased Simple Reaction Time. Considering that decrements in complex performance are commonly associated with fatigue, the stability or improvement of the more complex cognitive tasks was unexpected. Given that increasing effort is required to maintain performance as time-on-task increases, performance changes within pre and post-training trials were compared. While performance was stable or improved in the pre-training session, complex task performance deteriorated during post-training trials. The results are consistent with the hypotheses that fatigued individuals maintain complex cognitive task performance by exerting increased effort, but that increasing effort becomes increasingly difficult even during brief assessments.