title: Right, left, and center: how does cerebral asymmetry mix with callosal connectivity?
abstract: BACKGROUND
  Prior research has shown that cerebral asymmetry is associated with differences in corpus callosum connectivity. Such associations were detected in histological and anatomical studies investigating callosal fiber size and density, in neuroimaging investigations based on structural and diffusion tensor imaging, as well as in neuropsychological experiments. However, little is known about typical associations between these factors, and even less about the relative influences of magnitude and direction of cerebral asymmetries. Here, we investigated relationships between callosal connectivity and cerebral asymmetry using precise measures of callosal thickness and selected cerebral structures. We considered both the direction and magnitude of the asymmetries.
  
  
  METHODS
  Associations between cerebral asymmetry and callosal thickness were investigated in 348 cognitively healthy older individuals.
  
  
  RESULTS
  The magnitude and direction of cerebral lateralization were significant independent predictors of callosal thickness. However, associations were small. Leftward asymmetry and increased magnitude of asymmetry were generally associated with increased callosal thickness, mostly in the callosal midbody and isthmus.
  
  
  CONCLUSIONS
  When a large sample of normal individuals is considered, cerebral asymmetries are only subtly associated with callosal thickness.
authors.affiliation: Centre for Research on Ageing, Health, and Wellbeing, Australian National University, Canberra, Australia. nicolas.cherbuin@anu.edu.au
authors.forename: Nicolas
authors.initials: N
authors.lastname: Cherbuin
authors.forename: Eileen
authors.initials: E
authors.lastname: Luders
authors.forename: Yi-Yu
authors.initials: YY
authors.lastname: Chou
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Toga
authors.forename: Kaarin J
authors.initials: KJ
authors.lastname: Anstey
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003337:Corpus Callosum / Q000502:physiology*; D004292:Dominance, Cerebral; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged