[Job quality evaluation with regard to individual stress tolerance of operators]

Male test-subjects (n = 8, 25 to 36 years of age) were kept awake and working for 67 hrs. in an anechoic room. Every 1-2 hours the test-subjects performed eye-tracking of rhythmic light points with an abrupt and unexpected change of frequency. The task was to strike the key the moment the frequency was noticed to have changed. One test session took 10 to 15 minutes; depending on test duration, the number of frequency change could be from 38 up to 59-60. The moments of frequency change and keystroke were registered. Latent reaction time was determined (LRT). Individual LRT values and variations (SD) were evaluated. A statistically significant correlation between individual LRT values and variations was established, i.e. high SD corresponded to high LRT values and visa versa. Thus the worst test results were associated with high LRT values and variations, whereas, on the contrary, the best test results were characterized by low LRT values and variations. Data of the investigation are subject to analysis with regard to their relation to operator's stress tolerance; possible neurophysiological mechanisms of this relation are discussed.