Interhemispheric interaction affected by identification of Chinese characters.

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