Neuroendocrine responses and psychomotor test results in subjects participating in military pilot selection

Background: Military flying sets high demands on the mental performance and stress tolerance of pilots. Neuroendocrine responses could be a method for evaluating stress tolerance. Methods: Psychological workload and neuroendo crine responses associated with the psychomotor Wiener's test were studied in 80 male volunteers. These personnel had applied for the basic military f lying program of the Finnish Air Force (FAF). After the first blood sample at 0930 h, the subjects were randomly assigned to test (n = 40) and control groups (n = 40). The test group performed the psychomotor test, which last ed 10 min. The second blood sample was collected 1 min after the test. The control group was clinically examined and the blood sample was taken in the same way. Results: A high plasma ACTH level before the psychomotor test pr edicted (r = 0.36, p = 0.02) a poor overall result in the psychomotor test. After the psychomotor test, plasma adrenocorticotropin (ACTH) and P-endorp hin levels were significantly higher than before the test. They were also h igher than in the control group. Plasma cortisol and prolactin levels incre ased after the psychomotor test, but the increase was not statistically sig nificant. High ACTH, cortisol and prolactin increments were specific to a h igh amount of delayed (over 2 s) psychomotor responses, as a marker of info rmation overload. Conclusions: Elevated plasma ACTH, cortisol and prolactin levels, after the psychomotor test, were associated with a high amount of the delayed responses. This indicates that high neuroendocrine responses we re connected with problems in stress tolerance during information processin g. High neuroendocrine reactions under information load could, therefore, b e used for identification of lowered stress tolerance.