title: Effects of social interaction on monocular/unihemispheric sleep in male and female domestic chicks.
abstract: The monocular/unihemispheric sleep was studied in male and female domestic chicks reared socially. In first week post-hatching, chicks were reared in couples whilst during the second week, for half of the chicks the cospecific was maintained (Conspec-chicks) and for the other half the conspecific was removed (No-Conspec-chicks). During the first week, female chicks showed a bias for more left-eye closure/right unihemipheric sleep, whilst male chicks did not show any eye-closure bias. In the second week, both female and male Conspec-chicks showed a bias for right eye-closure/left unihemispheric sleep. Female No-Conspec-chicks did not show any eye-closure bias whilst male No-Conspec-chicks showed a bias for more left eye-closure/right unihemispheric sleep. Based on the role of the avian brain lateralization, a bias for more right or left eye-closure could be associated with a prevalent activation of left or right hemisphere during wakefulness. Eye-opening during sleep might be connected with the hemisphere that was not or was less activated during wakefulness or with lateralization of the environment monitoring against predation.
authors.affiliation: Department of General Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Bobbo
authors.forename: Giorgio
authors.initials: G
authors.lastname: Vallortigara
authors.forename: Gian G
authors.initials: GG
authors.lastname: Mascetti
mesh_terms: D000367:Age Factors; D000818:Animals; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D002645:Chickens; D004292:Dominance, Cerebral / Q000502:physiology*; D023882:Dominance, Ocular / Q000502:physiology; D005260:Female; D007173:Imprinting, Psychological / Q000502:physiology*; D008297:Male; D012737:Sex Factors; D012890:Sleep / Q000502:physiology*; D012919:Social Behavior; D012931:Social Environment; D012934:Social Isolation / Q000523:psychology; D015349:Vision, Monocular / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology