The number of active palmar sweat glands (palmar sweat index,PSI) as an activation measure in field studies

The number of active sweat glands within a defined area of a fingertip, called the palmar sweat index (PSI), can be easily determined by means of the plastic fingerprint method. Two experiments were carried out to demonstrate the applicability of this technique in field research and to investigate the properties of the PSI as an activation parameter. In Experiment 1 (in a blood donors’ ward), PSI rose significantly during venous puncture and dropped after the cannula had been installed. In Experiment 2 (in a dental office), PSI values increased when patients were seated in the dental chair and rose to a higher level at the dentist’s entry. Values after treatment were significantly lower. In both experiments, it was observed that the initial assessments yielded higher PSI values. This is best explained as a reaction to the assessment procedure itself, and it is recommended that the first two prints not be used for the determination of baseline values.