Dipartimento di Psicologia Generale, Università di Padova, Italy.
J Cogn Neurosci. 2010 May;22(5):1011-25. doi: 10.1162/jocn.2009.21232.
Although the dominant approach posits that developmental dyslexia arises from deficits in systems that are exclusively linguistic in nature (i.e., phonological deficit theory), dyslexics show a variety of lower level deficits in sensory and attentional processing. Although their link to the reading disorder remains contentious, recent empirical and computational studies suggest that spatial attention plays an important role in phonological decoding. The present behavioral study investigated exogenous spatial attention in dyslexic children and matched controls by measuring RTs to visual and auditory stimuli in cued-detection tasks. Dyslexics with poor nonword decoding accuracy showed a slower time course of visual and auditory (multisensory) spatial attention compared with both chronological age and reading level controls as well as compared with dyslexics with slow but accurate nonword decoding. Individual differences in the time course of multisensory spatial attention accounted for 31% of unique variance in the nonword reading performance of the entire dyslexic sample after controlling for age, IQ, and phonological skills. The present study suggests that multisensory "sluggish attention shifting"-related to a temporoparietal dysfunction-selectively impairs the sublexical mechanisms that are critical for reading development. These findings may offer a new approach for early identification and remediation of developmental dyslexia.
虽然主流观点认为发展性阅读障碍是由专门的语言系统缺陷引起的（即语音缺陷理论），但阅读障碍者在感觉和注意力处理方面表现出多种较低层次的缺陷。尽管它们与阅读障碍的联系仍然存在争议，但最近的实证和计算研究表明，空间注意力在语音解码中起着重要作用。本行为研究通过测量提示检测任务中视觉和听觉刺激的反应时，调查了阅读障碍儿童和匹配对照组的外源性空间注意力。与年龄和阅读水平对照组以及与非词解码较慢但准确的阅读障碍者相比，非词解码准确性较差的阅读障碍者的视觉和听觉（多感觉）空间注意力的时间进程较慢。在控制年龄、智商和语音技能后，多感觉空间注意力的时间进程的个体差异解释了整个阅读障碍者样本中非词阅读表现的 31%的独特方差。本研究表明，与颞顶叶功能障碍相关的多感觉“迟钝注意力转移”选择性地损害了阅读发展关键的亚词汇机制。这些发现可能为发展性阅读障碍的早期识别和矫正提供一种新方法。
