Eden Guinevere F, Wood Frank B, Stein John F
Department for Pediatrics, Georgetown University Medical Center, Washington, DC 20057, USA.
J Learn Disabil. 2003 May-Jun;36(3):216-28. doi: 10.1177/002221940303600302.
Although developmental dyslexia is often defined as a language-based reading impairment not attributable to low intelligence or educational or socioeconomic limitations, the behavioral manifestations of dyslexia are not restricted to the realm of language. Functional brain imaging studies have shed light on physiological differences associated with poor reading both inside and outside the classical language areas of the brain. Concurrently, clinically useful tests that elicit these nonlinguistic deficits are few. Specifically, the integrity of the dorsal visual pathway, which predominantly projects to the parietal cortex, remains underinvestigated, lacking easily administered tests. Here we present the Clock Drawing Test (CDT), used to test the visuoconstructive ability of children with and without dyslexia and garden-variety poor readers. Compared to typically reading children, many children with dyslexia and some garden-variety poor readers showed significant left neglect, as measured by the distribution of figures drawn on the left clock face. In the poor readers with dyslexia, we observed spatial construction deficits like those of patients with acquired right-hemisphere lesions. The results suggest that in some children with dyslexia, right-hemisphere dysfunction may compound the phonological processing deficits attributed to the left hemisphere. The CDT provides an easy opportunity to assess skills known to be associated with right-hemisphere parietal function. This test can be easily administered to children for both clinical and research purposes.
尽管发育性阅读障碍通常被定义为一种基于语言的阅读障碍，并非由低智力、教育或社会经济限制所致，但阅读障碍的行为表现并不局限于语言领域。功能性脑成像研究揭示了与大脑经典语言区域内外阅读能力差相关的生理差异。与此同时，能够引发这些非语言缺陷的临床实用测试却很少。具体而言，主要投射到顶叶皮质的背侧视觉通路的完整性仍未得到充分研究，缺乏易于实施的测试。在此，我们介绍时钟绘图测试（CDT），该测试用于检测有阅读障碍和无阅读障碍的儿童以及普通阅读能力差的儿童的视觉构建能力。与正常阅读的儿童相比，许多有阅读障碍的儿童以及一些普通阅读能力差的儿童表现出明显的左侧忽视，这通过在时钟左半面绘制的图形分布来衡量。在有阅读障碍的阅读能力差的儿童中，我们观察到了与后天性右半球病变患者类似的空间构建缺陷。结果表明，在一些有阅读障碍的儿童中，右半球功能障碍可能会加重归因于左半球的语音处理缺陷。时钟绘图测试提供了一个轻松的机会来评估已知与右半球顶叶功能相关的技能。该测试可轻松应用于儿童，用于临床和研究目的。
