Skip to main content
Article
Behavioral, Neurophysiological and Evolutionary Perspectives on Unihemispheric Sleep
Neuroscience & Biobehavioral Reviews (2000)
  • Niels C. Rattenborg
  • Charles J. Amlaner, Kennesaw State University
  • Steven L. Lima, Indiana State University
Abstract

Several animals mitigate the fundamental conflict between sleep and wakefulness by engaging in unihemispheric sleep, a unique state during which one cerebral hemisphere sleeps while the other remains awake. Among mammals, unihemispheric sleep is restricted to aquatic species (Cetaceans, cared seals and manatees). in contrast to mammals, unihemispheric sleep is widespread in birds, and may even occur in reptiles. Unihemispheric sleep allows surfacing to breathe in aquatic mammals and predator detection in birds. Despite the apparent utility in being able to sleep unihemispherically, very few mammals sleep in this manner. This is particularly interesting since the reptilian ancestors to mammals may have slept unihemispherically. The relative absence of unihemispheric sleep in mammals suggests that a trade off exists between unihemispheric sleep and other adaptive brain functions occurring during sleep or wakefulness. Presumably, the benefits of sleeping unihemispherically only outweigh the costs under extreme circumstances such as sleeping at sea. Ultimately, a greater understanding of the reasons for little unihemispheric sleep in mammals promises to provide insight into the functions of sleep, in general.

Keywords
  • unihemispheric,
  • slow-wave sleep,
  • sleep function,
  • sleep mechanisms,
  • sleep regulation,
  • functional lateralization,
  • predator detection,
  • aquatic mammals,
  • birds,
  • reptiles
Publication Date
December, 2000
Citation Information
Niels C. Rattenborg, Charles J. Amlaner and Steven L. Lima. "Behavioral, Neurophysiological and Evolutionary Perspectives on Unihemispheric Sleep" Neuroscience & Biobehavioral Reviews Vol. 24 Iss. 8 (2000)
Available at: http://works.bepress.com/charles_amlaner/22/