title: Brain activation on pre-reading tasks reveals at-risk status for dyslexia in 6-year-old children.
abstract: In this fMRI-study, 6-year-old children considered at risk for dyslexia were compared with an age-/gender-matched control group for differences in brain activation when presented with visual stimuli differing in demands for literacy processing. Stimuli were nameable pictures, brand logos familiar to children, and written words - these were either regularly spelled using early-acquired rules ("alphabetic") or more complex ("orthographic"). Brain responses distinguished between the presentation conditions, as a function of group, within many cortical areas. Activation in the alphabetic and orthographic conditions in the left angular gyrus correlated with individual at-risk index scores, and activation in inferior occipito-temporal regions further indicated differential activation for the two groups related to orthographic processing, especially. Since similar patterns are reported in adult dyslexics when processing written words, it appears that sensitivity to the cortical differentiation of reading networks is established prior to formal literacy training.
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen, Norway. karsten.specht@psybp.uib.no
authors.forename: Karsten
authors.initials: K
authors.lastname: Specht
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hugdahl
authors.forename: Sonja
authors.initials: S
authors.lastname: Ofte
authors.forename: Merethe
authors.initials: M
authors.lastname: Nygård
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
authors.forename: Elena
authors.initials: E
authors.lastname: Plante
authors.forename: Turid
authors.initials: T
authors.lastname: Helland
mesh_terms: D001931:Brain Mapping; D016022:Case-Control Studies; D002648:Child; D004410:Dyslexia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D016555:Matched-Pair Analysis; D009483:Neuropsychological Tests; D009664:Norway; D018570:Risk Assessment