Bing Yu MD, Presenter: Nothing to Disclose

Na Liu MD, Abstract Co-Author: Nothing to Disclose

Qiyong Guo MD, Abstract Co-Author: Nothing to Disclose

Guoguang Fan PhD, Abstract Co-Author: Nothing to Disclose

To map cortical areas associated with semantic processing of auditory Chinese words in literate and illiterate children in order to investigate whether literacy influences the functional hemispheric balance in language-related regions of children using event-related (ER) fMRI.

FMRI data were collected on 24 healthy right-handed Chinese children volunteers (12 illiterates, 5.4 to 7.8 years, with a median age of 6.5 years; 12 literates, 5.3 to 7.6 years, with a median age of 6.3 years) during performance of auditory Chinese word and simple tone judgement paradiagm using a 3.0 T MR scanner. There were 36 auditory word stimulus pairs (18YES, 18NO) and 36 simple tone stimulus pairs (18YES, 18NO) in the paradiagm. The interstimulus interval varied from 6 to 10 seconds. The percent of correct responses (PCR) and the mean reaction time to correct response (mRT) were recorded and compared. FMRI data analysis was performed by SPM2. An asymmetry index (AI) for each brain region was calculated using SPM toolbox LI-tools. An AI >0.20 with negative value was considered as right hemispheric dominance while positive value as left hemispheric dominance,an AI between 0.20 and 0.20 was considered as a bilateral activation pattern.

Illiterate children had lower PCR and longer mRT than literates in  judgement of the word stimulus pairs (P<0.05), however the PCR and mRT of  judgement of the tone stimulus pairs did not differ between groups. The semantic processing of Chinese characters were localized in frontal gyrus (BA 44,45), and bilateral superior temporal  gyrus(BA 22) . Left lateralization in superior temporal gyrus was more significant in literate children (0.63±0.24 vs 0.39±0.16, P<0.05).

Literacy influences the functional lateralization in language-related regions of children especially in superior temporal gyrus.

Literacy influences the functional hemispheric balance in language-related regions of children especially in temporal lobe .

Yu, B, Liu, N, Guo, Q, Fan, G, The Influence of Literacy on Language Lateralization of Children: An Event-related fMRI Study.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9005723.html