Dipartimento di Psicologia Generale e Centro di Scienze Cognitive, Università di Padova, Padova, Italy.
Neuropsychologia. 2010 Nov;48(13):3793-801. doi: 10.1016/j.neuropsychologia.2010.09.002. Epub 2010 Sep 15.
Reading acquisition requires, in addition to appropriate phonological abilities, accurate and rapid selection of sublexical orthographic units by attentional letter string parsing. Spatio-temporal distribution of attentional engagement onto 3-pseudoletter strings was studied in 28 dyslexic and 55 normally reading children by measuring attentional masking (AM). AM refers to an impaired identification of the first of two sequentially presented masked objects (O1 and O2). In the present study, O1 was always centrally displayed, whereas the location of O2 (central or lateral) and the O1-O2 interval were manipulated. Dyslexic children showed a larger AM at the shortest O1-O2 interval and a sluggish AM recovery at the longest O1-O2 interval, as well as an abnormal lateral AM. More importantly, these spatio-temporal deficits of attentional engagement were selectively present in dyslexics with poor phonological decoding skills. Our results suggest that an inefficient spatio-temporal distribution of attentional engagement - probably linked to a parietal lobule dysfunction - might selectively impair the letter string parsing mechanism during phonological decoding.
阅读能力的获得除了需要适当的语音能力外，还需要注意力通过字符串切分准确而快速地选择次词汇的正字法单位。本研究通过测量注意掩蔽（Attentional Masking，AM）来研究 28 名阅读障碍儿童和 55 名正常阅读儿童对 3 个伪字母串的注意力投入的时空分布。AM 是指对两个连续呈现的掩蔽物体（O1 和 O2）中的第一个物体识别受损。在本研究中，O1 总是在中央显示，而 O2 的位置（中央或外侧）和 O1-O2 间隔被操纵。阅读障碍儿童在最短的 O1-O2 间隔处表现出较大的 AM，在最长的 O1-O2 间隔处 AM 恢复较慢，并且存在异常的外侧 AM。更重要的是，这些注意力投入的时空缺陷仅存在于语音解码能力较差的阅读障碍者中。我们的研究结果表明，注意力时空分布效率低下——可能与顶叶功能障碍有关——可能会选择性地损害语音解码过程中的字母串切分机制。
