title: [New data on the genesis of sleep-wakefulness rhythm in children aged 4-15 months].
abstract: The present study deals with the ontogeny of the sleep-wakefulness rhythm in 12 children from the 4th to the 15 month of age. The main findings were as follows: 1. The circadian rhythm of wakefulness and sleep is clearly sep up as of 4 months of age and is characterized by 3 main parameters: a long uninterrupted night sleep period which includes the time interval from midnight to 4 a.m. The duration of this period of time is always equal to or higher than 400 min. The periodicity of the last falling asleep before midnight and the periodicity of the first awakening after midnight are equal or very close to 24 hours. Both seem to be mutually adjusted or connected to each other. 2. Some ages are characterized by significant changes in the daily distribution of the number and duration of sleep spans. 3. These changes suggest the existence of several ultradian rhythmicities which prevail successively throughout the development period under study. 4. There are many important differences between girls and boys.
authors.affiliation: Unité 70 l'Institut National de la Santé et de la Recherche Médicale, Montpellier.
authors.forename: G
authors.initials: G
authors.lastname: de Roquefeuil
authors.forename: M
authors.initials: M
authors.lastname: Djakovic
authors.forename: H
authors.initials: H
authors.lastname: Montagner
mesh_terms: D000367:Age Factors; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012737:Sex Factors; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
vernacular_title: Données nouvelles sur la genèse du rythme veille-sommeil de l'enfant de 4 mois à 15 mois.