空间书写障碍的个案研究

A Case Study About Spatial Dysgraphia

根据书写加工理论,从异形字水平、图解动作模式水平和神经动作执行水平三个方面,综合考察一例空间书写障碍儿童的认知加工特点。结果表明(1)个案QY的异形字水平出现选择性损伤,在视觉整体特征的知觉加工上存在困难,导致自发书写的汉字难以辨识,存在严重的间架结构问题。(2)个案QY在图解动作模式水平以及神经动作执行水平上表现正常。

Introduction Spatial dysgraphia is a type of writing disorders. It is characterized by irregularity of writings and poor coordination of writing movements. Children with spatial dysgraphia are usually normal in motor and language development. According to the theory of writing process, the mechanism of spatial dysgraphia lies in the level of allograph and graphic motor pattern. And deficit in the latter one is the main cause of spatial dysgraphia of Western words. As to Chinese developmental dysgraphia, there＇s only one report about a case of dysgraphia caused by developmental coordination disorder. So far, no report has been published on Chinese spatial dysgraphia. Method QY is a 9 year old boy in the third grade of elementary school. He was normal in reading and motor development, but showed serious deficits in the legibility and spacing of handwriting. This deficit only appeared in spontaneous writing, with copying relatively normal. The control group consisted of five children with normal writing abilities. QY and normal children were matched in physiological age, IQ and reading level. Based on the theory of writing process,we studied the cognitive processing characters of a child with spatial disgraphia from three levels： allograph and graphic motor pattern and neuromuscular execution. The allograph level included visual image test, visual and spatial memory test, and visual holistic process test. In the graphic motor pattern level, there are motor sequences memory test, motor image test and motor coordination tests, the latter test then included four tests： visual discrepancy detection, tactical recognition, muscular movement judgment and interference in copied writing. Finally, test in the neuromuscular execution level was a finger tapping task. Results （1） The case QY have selective impairments in allograph level; he was difficult in holistic visual processes, which lead to the illegibility and improper structure of his spontaneous handwritings. But in other aspects （i.e. visual image and visual and spatial memory）, no significant difference was obtained between QY and normal children. （2） The case QY are normal in graphic motor pattern level and neuromuscular execution level. Especially in the velocity of neuromuscular execution, the performance of QY was significantly higher than the normal children. Conclusions The case QY was a typical spatial dysgraphic child. The cognitive deficits primarily lay on the allograph level, characterized by the difficulties in holistic visual processes. The writing processes of QY were normal in the graphic motor pattern and neuromuscular execution level.