Different occipito-temporal activations in Chinese literate and illiterate subjects during Chinese character processing

Recent imaging studies have identified a region in occipito-temporal cortex essential for reading and labeled it as the visual word form area (VWFA). Several studies suggested that the development of this word specific region is closely related to the experience with words. In this study, two groups of Chinese subjects, one literate and the other illiterate, were asked to compare two Chinese characters presented at left and right side of a fixation point and decide whether they were the same character or not. Similar comparison of simple figures was used as control condition. We found stronger activation to Chinese characters than to simple figures in left and right hemispheric occipito-temporal regions in both literate and illiterate subjects. However, at the peak voxels revealed by Chinese character and simple figure contrast, the response to Chinese character stimuli in left occipito-temporal region of literate subjects was significantly stronger than that in the right one, whereas in illiterate subjects no such hemispheric preference was observed. We propose that the enhancement of the left peak voxel activation in literate group is due to their long-time acquaintance with reading.