engleski

Linear analyses of HRV during an easy and difficult exam

Different investigations on students have shown that perceived exam stress increases as the exams approaches, depending, inter alia, on the difficulty of exams. The perceived difficulty could also, in part, determine emotional component and mental effort, which are the two major components of exam stress. Previous studies on this subject did not include continuous measurements and registration of physiological reactions to stress during exam situations, therefore mental and emotional components of stress could not be assessed properly, neither could their contributions to the exam stress, generally. The aim of this study was to continuously measure and register cardiac R-R intervals before, during and after an easier and a difficult exam. The analysis of results, which would include spectral analysis as well, could separate emotional and mental stress components, during the exams. Twelve subjects, 18 to 19 years of age, who had no experience with exams at the university level, took part in the study. For the purpose of the study, an easy and a difficult exam were chosen from eight exams of the first year psychology course syllabus. Their difficulty was assessed and expressed in z-values, by 60 older students who had passed them. The rating of the exams on z-scale was -2.27 for easier, and 1.37 for difficult exam. The levels of anxiety, high activation and exam apprehension, were measured before the exams, indicating much higher stress before the difficult exam. Changes in cardiac R-R intervals, which were continuously registered five minutes before, thought, and up to five minutes after the exams, also indicated significantly higher stress and mental effort during more difficult exam. By the use of spectral analysis, and its SMI index, it was shown that the spectral frequency suppression, between 0.02-0.06 and 0.07-0.14 Hz, pointed out to an increase in emotional and mental load, respectively. The SMI index also showed the peak effects of the two stress components during the exams itself, indicating the possibility of their summation in exam situations.

linear analyses; HRV; exams

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