DEFINITION OF A RESPONDER - ANALYSIS OF BEHAVIORAL, CARDIOVASCULAR, AND ENDOCRINE RESPONSES TO VARIED WORKLOAD IN AIR-TRAFFIC-CONTROLLERS

Individual differences in behavioral, cardiovascular, and endocrine re sponses to varying workload among 381 air traffic controllers were ass essed using random regression modeling. Although most men showed signi ficant increases in behavioral arousal associated with increasing plan es, there were major individual differences in response in systolic an d diastolic blood pressure, heart rate, and cortisol. Approximately 20 % to 25% of those studied had large increases in each of these domains , along with a smaller group showing inverse responses in heart rate a nd cortisol. There was also evidence of a smaller number of enhanced r esponders within the highest groups, who tended to have more missing v alues at higher levels of workload. There was convergence in the defin ition of responders using three statistical strategies: random regress ion, correlational analyses, and ANOVA. Response in one physiological/ behavioral domain was essentially independent of response in another, supporting the conclusion of specificity, rather than a global tendenc y to respond to increasing work load.