The aim of this study was to examine whether the parameters of cardiac R-R intervals reflect the changes in the emotional and mental components of stress during a difficult and an easy exam. Twelve subjects, 18 to 19 years of age, with no previous experience with exams at university level, took part in the study. The levels of anxiety, high activation and exam apprehension were assessed before a difficult and an easy exam. Subjects’ cardiac R-R intervals were continuously registered in the period of five minutes before the exam, during the whole exam, and five minutes after the exam by the Power Lab polygraph. The level of anxiety, high activation and exam apprehension were higher before the difficult exam than before the easy exam. Shorter and more regular R-R intervals were found dur-
ing the difficult exam as compared to the easy exam. No significant differences in the spectral analyses parameters were found between the difficult and the easy exam, while the differences were significant between the pre-exam, exam and the post-exam periods
