INDIVIDUAL-DIFFERENCES IN PHYSIOLOGICAL A ND BEHAVIORAL DIURNAL-VARIATIONS

The present work reviews the main individual differences which art:of interest in the field of circadian rhythms. For this reason, and in th e first place, the rhythmic characteristics of the following physiolog ical parameters are presented: body temperature, blood pressure and he art rate. In addition, data which highlight the factors that influence the values obtained for these physiological variables from a homeosta tic perspective-without taking into account time of day-are also outli ned. The individual differences reviewed are the dimension of personal ity-extroversion and neuroticism, the morningness factor, the age, the gender and tobacco consumption. Rhythmic differences in physiological and behavioral parameters-subjective and objective-are taken into acc ount for each of the above variables. Although reference is also made to the homeostatic findings liable to be considered as a function of t ime of day.