Na Liu MD, Presenter: Nothing to Disclose

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

Bing Yu MD, Abstract Co-Author: Nothing to Disclose

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

To map cortical areas associated with semantic processing of Chinese characters 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 38 healthy right-handed Chinese children volunteers (19 illiterates, 10.4 to 12.8 years, with a median age of 11.5 years;19 literates, 11.7 to 13.3 years, with a median age of 12.0 years) during performance of Chinese character and easy figure judgement. ER fMRI was performed using a 3.0 T MR scanner. The total fMRI scan duration was 576s in which there were 36 language stimulus pairs (18YES, 18NO) and 36 control stimulus pairs (18YES, 18NO). Each stimulus pairs lasted for 4s and the interstimulus interval varied from six to ten seconds. Data analysis was performed by SPM2. An asymmetry index (AI) for each region was calculated using the formula of Left-Right/Left+Right. 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.

Mean reaction times for the Chinese character judgements were significantly shorter in literate group compared with the illiterate group (P<0.01). Chinese character judgements versus easy figure judgement activated left middle frontal gyrus(BA46/9, weaker on the right), bilateral parieto-temporal junctions (BA7/40/39) and bilateral occipito-temporal regions ( BA17/18/19/37/20 ) in the literate subjects (P<0.05), while peak activations in bilateral occipito-temporal regions (BA17/18/19/20/37) and weak activations in bilateral parietal lobule (BA40) were present in the illiterate group (P<0.05). The semantic processing areas of Chinese characters through literate versus illiterate were localized in left middle frontal gyrus(BA9), left angular gyrus (BA39) (P<0.05).  AIs in middle frontal regions, posterior parietal lobule and fusiform gyrus were 0.88,0.65, 0.33 for literate group, and -,0.16,0.24 for illiterate group respectively.  

Literacy influences the functional hemispheric balance in related regions of Chinese language processing , with a left-lateralization of middle frontal gyrus and angular gyrus, excluding cumulative life-span effects.

 

Liu, N, Fan, G, Yu, B, Guo, Q, Language Processing in the Literate and Illiterate Children: An Event-related fMRI Study.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6014647.html