title: Structural and functional reorganization of the corpus callosum between the age of 6 and 8 years.
abstract: The establishment of an efficient exchange of information between the cerebral hemispheres is of crucial importance in the developing functionally lateralized brain. The corpus callosum, the major connection between the cerebral hemispheres, grows constantly throughout childhood and adolescence. However, behavioral studies suggest the existence of a critical time period for callosal functional development starting around the age of 6 years. In the present longitudinal study, examining a cohort of 20 children at the age of 6 and 8 years, we assessed the relationship between structural and functional callosal development during this time period. The structural development was quantified by calculating the increase in callosal thickness using a shape-based computational analysis of the mid-sagittal corpus callosum as obtained with magnetic resonance imaging. The functional development was assessed with a speech discrimination task based on the dichotic presentation of consonant-vowel syllables. The statistical analysis revealed that children whose callosal isthmus increased in thickness over the course of 2 years showed a decrease in interhemispheric information transfer. However, children exhibiting a decrease in isthmus thickness revealed an increase in information transfer. These results might indicate a refinement process of the callosal connections to optimize the neuronal communication between the developing cerebral hemispheres.
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen, 5009 Bergen, Norway. rene.westerhausen@psybp.uib.no
authors.forename: René
authors.initials: R
authors.lastname: Westerhausen
authors.forename: Eileen
authors.initials: E
authors.lastname: Luders
authors.forename: Karsten
authors.initials: K
authors.lastname: Specht
authors.forename: Sonja H
authors.initials: SH
authors.lastname: Ofte
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Toga
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.forename: Turid
authors.initials: T
authors.lastname: Helland
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hugdahl
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D002648:Child; D003337:Corpus Callosum / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000254:growth & development / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D055815:Young Adult