Interhemispheric interaction affected by identification of Chinese characters

One aspect of interhemispheric processing that has recently received attent ion is whether it increases or decreases the processing power of the brain. The present study investigated whether dividing information between the he mispheres becomes more advantageous to task performance as computational co mplexity increases. A Chinese character matching task was given to subjects involving three levels of computational complexity (the pairs of character s being divided into three types, visually similar, homonymous, and synonym ous). The result showed no difference in performance between within-field a nd across-field presentation for visually similar characters. Performance w as significantly better for across field than within field with homophones and synonyms. However, the error rates of within field for phonetic matchin g was significantly higher than those for semantic matching. These results suggest that both the computational difficulty of materials and the intrins ic function of each hemisphere play a role in interhemispheric processing. (C) 1999 Academic Press.