Rumsey J M, Nace K, Donohue B, Wise D, Maisog J M, Andreason P
Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Md, USA.
Arch Neurol. 1997 May;54(5):562-73. doi: 10.1001/archneur.1997.00550170042013.
Developmental dyslexia is characterized by impaired word recognition, which is thought to result from deficits in phonological processing. Improvements during the course of development are thought to disproportionately involve orthographic components of reading; phonological deficits persist into adulthood.
To localize the neural correlates of impaired word recognition and phonological processing in men with developmental dyslexia.
Regional cerebral blood flow was measured with oxygen 15 positron emission tomography in 17 men with dyslexia and in 14 matched controls during the performance of phonological and orthographic tasks--pronunciation (reading aloud) and lexical decision making--designed to activate posterior and anterior perisylvian cortices, respectively.
Altered patterns of activation (reduced activation, unusual deactivation) were seen in dyslexic men in mid- to posterior temporal cortex bilaterally and in inferior parietal cortex, predominantly on the left, during both pronunciation and decision making. In contrast, dyslexic men demonstrated essentially normal activation of left inferior frontal cortex during both phonological and orthographic decision making.
These, along with prior findings, are compatible with a hypothesis of bilateral involvement of posterior temporal and parietal cortices in dyslexia.
发育性阅读障碍的特征是单词识别受损，这被认为是由语音处理缺陷导致的。发育过程中的改善被认为在很大程度上涉及阅读的正字法成分；语音缺陷会持续到成年期。
确定发育性阅读障碍男性中单词识别受损和语音处理的神经关联。
在17名阅读障碍男性和14名匹配的对照者执行语音和正字法任务（发音（大声朗读）和词汇决策）时，用氧15正电子发射断层扫描测量局部脑血流量，这些任务分别旨在激活颞叶周缘皮质后部和前部。
在发音和决策过程中，阅读障碍男性双侧颞叶中后部皮质和顶下皮质（主要在左侧）出现激活模式改变（激活减少、异常失活）。相比之下，阅读障碍男性在语音和正字法决策过程中左侧额下回皮质的激活基本正常。
这些结果与先前的发现一起，与后颞叶和顶叶皮质双侧参与阅读障碍的假说相符。
