A methodology to compensate for individual differences in psychophysiological assessment

The main methodological drawback to use physiological measures as indicators of arousal is the large interindividual variability of autonomic responses hindering the direct comparability between individuals. The present methodology has been tested in two cohorts (n1 = 910, n2 = 845) of pilot applicants during a selection procedure. Physiological data were obtained during two mentally demanding tasks and during a Flight Simulator Test. Five typical Autonomic Response Patterns (ARP) were identified by cluster analyses. Autonomic spaces were constructed separately for each group of subjects having the same typical ARP, on the basis of their normalized eigenvectors. The length of the vector sum of scores on autonomic space dimensions provided an integral index for arousal, labeled Psychophysiological Arousal Value (PAV). The PAV still reflected the changes in mental load during the tests, but equalized physiological differences among ARP-groups. The results obtained in the first cohort were verified in the second cohort