title: Mapping visual dominance in human sleep.
abstract: Sleep is a universal behavior, essential for humans and animals alike to survive. Its importance to a person's physical and mental health cannot be overstated. Although lateralization of function is well established in the lesion, split-brain and task based neuroimaging literature, and more recently in functional imaging studies of spontaneous fluctuations of the fMRI BOLD signal during wakeful rest, it is unknown if these asymmetries are present during sleep. We investigated hemispheric asymmetries in the global brain signal during non-REM sleep. Here we show that increasing sleep depth is accompanied by an increasing rightward asymmetry of regions in visual cortex including primary bilaterally and in the right hemisphere along the lingual gyrus and middle temporal cortex. In addition, left hemisphere language regions largely maintained their leftward asymmetry during sleep. Right hemisphere attention related regions expressed a more complicated relation with some regions maintaining a rightward asymmetry while this was lost in others. These results suggest that asymmetries in the human brain are state dependent.
authors.affiliation: Department of Radiology, Washington University, Saint Louis, MO 63110, USA. Electronic address: mcavoy@npg.wustl.edu.
authors.forename: Mark
authors.initials: M
authors.lastname: McAvoy
authors.affiliation: Department of Radiology, Washington University, Saint Louis, MO 63110, USA. Electronic address: anishmtira@wustl.edu.
authors.forename: Anish
authors.initials: A
authors.lastname: Mitra
authors.affiliation: Institute for Medical Psychology, Christian-Albrechts-Universitat zu Kiel, Kiel, Germany; Department of Neurology, Brain Imaging Center, Goethe-Universitat Frankfurt am Main, Frankfurt, Germany. Electronic address: tagliazucchi.enzo@googlemail.com.
authors.forename: Enzo
authors.initials: E
authors.lastname: Tagliazucchi
authors.affiliation: Department of Neurology, Brain Imaging Center, Goethe-Universitat Frankfurt am Main, Frankfurt, Germany; Department of Neurology, Christain-Albrechts-Universitat zu Kiel, Kiel, Germany. Electronic address: helmut@laufs.com.
authors.forename: Helmut
authors.initials: H
authors.lastname: Laufs
authors.affiliation: Department of Radiology, Washington University, Saint Louis, MO 63110, USA; Department of Neurology, Washington University, Saint Louis, MO 63110, USA; Department of Neuroscience, Washington University, Saint Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University, Saint Louis, MO 63110, USA. Electronic address: marc@npg.wustl.edu.
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Raichle
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012890:Sleep / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult
keywords: Global signal; Hemispheric asymmetry; Language network; Lateralization; Sleep; Visual network