Phonological processing in dyslexic children: a study combining functional imaging and event related potentials.
Difficulties in phonological processing are currently considered one of the major causes for dyslexia. Nine dyslexic children and eight control children were investigated using functional magnetic resonance imaging (fMRI) during non-oral reading of German words. All subjects silently read words and pronounceable non-words in an event related potentials (ERP) investigation, as well. The fMRI showed a significant difference in the activation in the left inferior frontal gyrus between the dyslexic and control groups, resulting from a hyperactivation in the dyslexics. The ERP scalp distribution showed a significant distinction between the two groups concerning the topographic difference for left frontal electrodes in a time window 250-600 ms after stimulus onset for non-word reading. Both the fMRI and the ERP results support differences in phonological processing between dyslexic and normal-reading children.
Georgiewa
Petra
P
Department of Child and Adolescent Psychiatry, Friedrich-Schiller-University of Jena, Philosophenweg 3-5, D-07740, Jena, Germany. georgiewa@landgraf.med.uni-jena.de
Rzanny
Reinhard
R
Gaser
Christian
C
Gerhard
Uwe Jens
UJ
Vieweg
Uta
U
Freesmeyer
Daniela
D
Mentzel
Hans Joachim
HJ
Kaiser
Werner Alois
WA
Blanz
Bernhard
B
D002648:Child; D004410:Dyslexia / Q000175:diagnosis / Q000503:physiopathology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010700:Phonetics; D011932:Reading; D014796:Visual Perception / Q000502:physiology*