Title
Word frequency effects in the left IFG in dyslexic and normally reading children during picture naming and reading.
Abstract
Word frequency effects have been reported in numerous neuroimaging studies with typically reading adults, emphasising the role of the left inferior frontal gyrus (LIFG). Within LIFG, different cytoarchitectonic modules (areas 44 and 45) have been related to phonological vs. lexico-semantic processing, respectively. This fMRI study investigated the differential impact of word frequency on LIFG activation in reading and picture naming in primary school children with and without developmental dyslexia. All children showed the typical LIFG frequency effect in both tasks. The effect was comparable in a fronto-orbital region anterior-inferior adjacent to area 45. During reading but not picture naming, a second effect was observed in area 44. Here, the fMRI effect for lexical frequency was stronger for the dyslexic than the normal readers. These findings demonstrate the neural underpinnings of a selective deficit in dyslexic children in the graphemic input lexicon, whereas abstract lexical representations appear to be processed equally well in dyslexic and normally reading children. To conclude, the present fMRI study demonstrated differential impact of word frequency on LIFG activation in primary school children during reading but not picture naming. Apart from extending previous knowledge from studies with adults to childhood, the study sheds further light on a potential neural mechanism for deficient grapheme-to-phoneme conversion in dyslexic children.
Year
DOI
Venue
2011
10.1016/j.neuroimage.2011.05.033
NeuroImage
Keywords
Field
DocType
fMRI,Language production,Broca's region,Reading acquisition,Grapheme-to-phoneme conversion,BA 44,BA 45,Area 44,Area 45
Broca's region,Word lists by frequency,Psychology,Cognitive psychology,Lexicon,Language production,Neuroimaging,Left inferior frontal gyrus,Dyslexia
Journal
Volume
Issue
ISSN
57
3
1053-8119
Citations 
PageRank 
References 
2
0.39
12
Authors
5
Name
Order
Citations
PageRank
Marion Grande131.09
Elisabeth Meffert231.09
Walter Huber3203.08
Katrin Amunts438937.30
Stefan Heim514312.36