Diurnal variation in energetic arousal, tense arousal, and hedonic tone in extreme morning and evening types.

The aim of the present study was to examine levels of energetic arousal (EA), tense arousal (TA), and hedonic tone (HT) in individuals with different circadian preferences. Subjects were males with extreme either morning (M-type) or evening (E-type) preferences (N=31), selected using the Morningness-Eveningness Questionnaire cutoff points derived from the Polish population norms. They completed the UWIST Mood Adjective Check List every 1.5 h between 08:00 to 20:00 h in laboratory conditions. The obtained data showed higher levels of TA and lower levels of HT in E-types over the whole day as compared to M-types. As for EA, M-types showed higher levels than E-types between 08:00 to 17:00 h, but the two groups showed no differences during the later hours of the day. Both groups were found to exhibit similar diurnal patterns in TA and HT, and dissimilarity between M-types and E-types appeared in the daily course of EA. The results show the three-dimensional model of mood is more advantageous in M-types than in E-types during the hours of typical human activity.