Mirror writing in right-handers and in left-handers: a study using Chinese characters

The mechanism of mirror writing was investigated using legal Chinese characters and illegal pseudocharacters. It was found from the results of right-handers in experiment 1 that the performance of normal writing and mirror writing for legal characters was better than that of normal writing and mirror writing for pseudocharacters. A reasonable explanation for this character-superiority effect is that normal engrams and mirror engrams exist only for legal characters but not for pseudocharacters. Further analysis revealed that the character-superiority effect took place in normal writing only when the right hand was used and the same effect was observed in mirror writing only when the left hand was used. It seemed that the normal engrams used in normal writing were stored in the left hemisphere while the mirror engrams used in mirror writing were stored in the right hemisphere. The results in experiment 2 from the left-handers showed the similar pattern as that of the right-handers. The mirror-engram hypothesis seems to be the best mechanism to account for the performance difference of right hand and left hand in mirror writing.