INFLUENCE OF MORNINGNESS EVENINGNESS PREFERENCE IN THE RELATIONSHIP BETWEEN BODY-TEMPERATURE AND PERFORMANCE - A DIURNAL STUDY

The present paper is a study of the evolution of body temperature and performance during the walking part of the day and the relationship between these two variables in respect of Morningness- Eveningness preferences. On the basis of the scores obtained from the Horne and Östberg questionnaire, adapted and standardized for the Spanish population, three groups, each containing 8 subjects, were formed (Morning-types, Neither-types, Evening-types). Extraversion and sex were seen to be highly-influential, decisive factors. Two different tasks were tested: visual reaction time and verbal memory, and the correlation between the two was calculated. Each of the subjects was tested in six sessions spread out over the day. Our results show that Neither-type subjects are the least dispersed among the parameters studied, but they did not give intermediate values between extreme groups. The reaction time task reveals a certain correlation with temperature changes in Evening-types only. Monitoring of the memory task shows fluctuations unrelated to changes in temperature, and no characteristic group pattern appears from preference for a certain time of day. The correlation between the two tasks was not significant for any of the groups of subjects involved in the experiment. © 1991.