Abstract: Mirror writing (MW) is a phenomenon characterized by flipping a single letter, a whole word, or a string of letters during handwriting. The flipped handwritings can be normally recognized when projecting to a mirror. MW sometimes incorporates with mirror reading (MR), and these two phenomena are usually defined as mirror error (ME) in previous studies. Non-voluntary mirror error has been observed in children as well as patients with brain damage. Although ME has been found relating to factors such as handedness, gene, intelligence, and script system, brain mechanisms of these phenomena is still unclear and many questions are not answered: e.g., why ME occurred when children are in early stages of learning to write, and then disappeared with learning progress? If ME-associated gene leads to the failure of left-lateralization for language and thus the occurrence of ME, what’s the advantage and disadvantage of the gene type? Is there some special cognitive ability for MW children? What is the relationship between handedness, left-lateralization and language system? This paper systematically reviewed theories on MW or MR, including motor hypothesis, visual-spatial hypothesis, visual word-form hypothesis and leftward eye movement hypothesis. The existing findings in relationships between ME and factors such as handedness, intelligence, and gene were summarized, and the potential neural mechanisms underlying the generation and development of ME were also discussed. Investigations on this phenomenon will benefit our further understanding on mental processing for script-reading and writing, the acquisition of writing skill, and the principle of the object recognition system.

摘要： 镜像书写是指对单个字母、整个词或者字母串进行反方向书写，当将这些字母或者字投射到镜子上时，这些字母或者字可以被正常阅读。镜像书写现象有时伴随镜像阅读，二者在研究中统称“镜像错误”。非随意的镜像错误已经在儿童以及脑损伤病人身上被发现，并且与利手、基因、智商及书写系统等因素有联系，但对该现象的发生发展及脑机制的解释目前尚不确定。对该现象的研究和解释将有助于我们深入理解文字的加工机制、文字书写的习得以及物体识别系统的加工与组织原则。 本文系统评述了对镜像书写的理论解释，综合各方面研究阐述了镜像书写现象与利手、基因、智商等因素的关系，并探讨了该现象产生的潜在神经机制。

关键词: 镜像书写, 镜像阅读, 镜像错误, 脑机制, mirror writing, mirror reading, mirror error, brain mechanism