Differences in effective connectivity between dyslexic children and normal readers during a pseudoword reading task: an fMRI study.
OBJECTIVE
This fMRI study investigated phonological and lexicosemantic processing in dyslexic and in chronological age- and reading level-matched children in a pseudoword reading task.


METHODS
The effective connectivity network was compared between the three groups using a structural model including the supramarginal cortex (BA 40; BA: Brodmann area), fusiform cortex (BA 37) and inferior frontal cortex (BA 44/45) areas of the left hemisphere.


RESULTS
The results revealed differences in connectivity patterns. In dyslexic patients, in contrast with chronological age- and reading level-matched groups, no causal relationship was demonstrated between BA 40 and BA 44/45. However, a significant causal relationship was demonstrated between BA 37 and BA 44/45 both in dyslexic children and in the reading level-matched group.


CONCLUSIONS
These findings were interpreted as evidence for a phonological deficit in developmental dyslexia.
Quaglino
V
V
Efficience Cognitive Dans les Conduites Humaines d'Apprentissage et de Travail, Ecchat, EA 2092, Université de Picardie Jules-Verne, Amiens, France.
Bourdin
B
B
Czternasty
G
G
Vrignaud
P
P
Fall
S
S
Meyer
M E
ME
Berquin
P
P
Devauchelle
B
B
de Marco
G
G
D000328:Adult; D001921:Brain / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology; D004410:Dyslexia / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D015233:Models, Statistical; D009434:Neural Pathways / Q000503:physiopathology; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology; D011932:Reading
D010100:Oxygen