Neuroendocrine responses to psychological workload of instrument flying instudent pilots

Background: information processing and stress tolerance are necessary featu res for instrument flying (IFR), especially among student pilots. Psycholog ical workload of IFR flight may lead to stress reactions such as neuroendoc rine activity. Methods: Neuroendocrine responses to an IFR flight with Vink a piston-engined primary trainer were studied in 35 male volunteers who par ticipated in the basic military flying course of the Finnish Air Force (FAF ). The student pilots performed a 40-min IFR flight mission and a control s ession on land in randomized order between 11.00 h and 15.00 h. The IFR fli ght included 3 NDB approaches and was evaluated by flight instructors. Bloo d samples were collected 15 min before, 5 min and GO min after the flight a s well as control session, and. Plasma ACTH, p-endorphin (BE), cortisol, pr olactin, adrenaline (A) and noradrenaline (NA) were measured. Psychological evaluations included psychomotor test (Wiener), Multi Coordination and Att ention Test ability tests and personality tests (CMPS and 16 PF). The overa ll psychological evaluation was made by an aviation psychologist. Results: Plasma ACTH was significantly higher before and 5 min after the flight comp ared with control levels, but plasma BE increased significantly only before the night. Plasma cortisol was significantly elevated before and 5 min aft er the flight. Plasma prolactin, NA and A increases were significant 5 min after the flight. High A levels after the flight correlated significantly w ith poor IFR flight performance as well as with poor psychomotor test resul ts. Conclusions: The plasma prolactin and NA increases after the night repr esented a direct type of stress reaction to the flight situation. The plasm a BE response to IFR flight was an anticipatory stress reaction, but plasma ACTH, cortisol and A responses included both anticipatory and direct types of stress reactions. Psychological factors, flight performance and neuroen docrine responses to IFR flight appear to be associated with each other. Th erefore, neuroendocrine reactions as a response to the psychological worklo ad of military flying could be used for identifying stress tolerance in mil itary pilots. Keywords: ACTH, beta-endorphin, cortisol, prolactin, adrenali ne, noradrenaline, stress, aerospace medicine, man.