Caratteristiche di soggetti capaci di estendere il proprio sonno per oltre 11 ore /Characteristics of subjects capable of extending their own sleep for more than 11

Studied traits associated with normal and extended sleep in 100 male and female university students who usually sleep 7-9 hrs each night but who can sleep 12-13 hrs (extended sleepers) and 100 male and female university students who usually sleep 7-9 hrs each night but who cannot extend sleep beyond 10 hrs (normal sleepers). Data on sociodemographic variables, sleep habits, circadian rhythms, and personality traits were obtained by semistructured interview and questionnaire. The Eysenck Personality Questionnaire (EPQ), the MMPI, the Morningness-Eveningness Questionnaire (J. A. Horne and O. Ostberg, 1977), and the Epworth Sleepiness Scale (M. W. Johns, 1991) were used. Sleep polygraph recordings were made for 6 normal and 6 extended sleepers. The results indicate that eveningness is associated with sleep extension. The characteristics of sleep extension compared to normal sleep include lower neuroticism scores, lower sleep efficacy during initial sleep phases, and higher sleepiness during the day.