汉语发展性阅读障碍亚类型的初步探讨

A Preliminary Study Subtypes of Chinese Developmental Dyslexia

以阅读水平匹配组为参照对29名汉语发展性阅读障碍儿童的认知缺陷模式进行了分析,并考察了不同亚类型阅读障碍儿童的汉字识别模式。结果表明汉语发展性阅读障碍存在不同的亚类型,以语音缺陷型、快速命名缺陷型及两者结合的双重缺陷型为主,与英语国家研究中的双重缺陷假设一致。语音缺陷型儿童汉字识别时有更多的语义错误,对声旁中的部分语音线索不敏感;快速命名缺陷型儿童汉字识别时依赖声旁语音线索,表现出阅读发展的一般延迟;双重或多重认知缺陷型是阅读损伤最严重的亚类型。

The phonological processing deficit is the major cognitive impairment of developmental dyslexia in alphabetic countries. Some researchers have suggested that there are different subtypes in dyslexia, such as surface or delayed dyslexia and dyslexia with rapid naming deficit. Chinese characters belong to ideogram, with one character usually denoting one morpheme ; they do not bear a grapheme-phoneme correspondence. An important question for developmental researchers is what the dominating cognitive deficit is in Chinese developmental dyslexia. Researchers in Hong Kong found that the rapid naming deficit and orthographical skills deficit were the primary cognitive deficits, and there was lower incidence with phonological deficit. However, researchers in Beijing found that Chinese developmental dyslexics mainly possessed morphological awareness deficit. One possible cause of the inconsistency was that the analysis of subtypes in the studies was based on chronological-age controls, which might make the direction of causality unclear between some cognitive deficits and dyslexia because the cognitive skills and reading abilities usually contained interactive relations. In the present study, we intended to further examine the subtypes of Chinese developmental dyslexia, in order to clarify the cognitive deficit profile in Chinese dyslexia. According to the low achievement definition, we selected 29 dyslexics from 654 children aged 9 - 12. 8 years, and comparison groups with appropriate chronological-age （26） and reading-levels （28）. Five reading-related cognitive skills were examined, including phonological awareness, rapid automatic naming, morphological awareness, orthographic skills and homophone choice task. Adopting one standard deviation cutoff criterion for every variable based on scores of reading- level controls, we explored the cognitive deficit profile of 29 Chinese developmental dyslexics. Finally Chinese character recognition test was administered in order to investigate whether the children＇s error pattern and regularity and frequency effect were distinct in different subtypes while reading characters. The main results are as follows. 1. There were different subtypes in Chinese developmental dyslexia, mainly including phonological dyslexia, dyslexia with rapid naming deficit, and dyslexia with double deficits of phonological awareness and rapid naming skills. A small proportion of dyslexics displayed orthographic-skill deficit. Finally, about one quarter of the dyslexics showed no severe cognitive deficits. 2. The dyslexics with phonological deficit exhibited more semantic errors while reading Chinese characters and were less able to detect the partial phonological information of the phonetic-radical in semantic-phonetic compounds. 3. The regularity-frequency effect patterns of children with rapid naming deficit were similar to those of the reading- level controls and revealed a general delay of reading development. They tended to recognize characters by the phonetic- radical. 4. The dyslexics with double or multiple cognitive deficits manifested the most severe reading impairment. The results indicate that the cognitive deficit profiles of Chinese developmental dyslexia were consistent with the- double-deficit hypothesis of English developmental dyslexia, illustrating a cross-character consistency. Furthermore,the interaction among the reading-related cognitive skills likely determined the severity of dyslexia. The findings have implications for the diagnosis and intervention of Chinese developmental dyslexia. However the origin of phonological and rapid naming deficit needs to be investigated.