Pitchford Nicola J, Funnell Elaine, De Haan Bianca, Morgan Paul S
University of Nottingham, University Park, Nottingham, UK.
Q J Exp Psychol (Hove). 2007 Sep;60(9):1187-96. doi: 10.1080/17470210701425845.
The right-hemisphere hypothesis of deep dyslexia has received support from functional imaging studies of acquired deep dyslexia following damage to the left cerebral hemisphere, but no imaging studies of cases of developmental deep dyslexia, in which brain damage is not suspected, have been reported. In this paper, we report the first evidence of right hyperactivation in an adult case of developmental deep dyslexia. Hyperactivation was observed in the right inferior frontal cortex during functional magnetic resonance imaging (fMRI) of the oral reading of imageable content words and nonwords to which imageable lexical responses were frequently made. No evidence of right hyperactivation was observed in the oral reading of function words, nor during the naming of imageable words in response to pictured objects. The results reveal strategic and selective use of right-hemisphere functions for particular types of written stimuli. We propose that children with developmental deep dyslexia compensate for their lack of phonological skills by accessing right-hemisphere imageable associations that provide a mnemonic for linking written forms to spoken names.
深层诵读困难的右脑半球假说已得到针对左脑半球受损后后天性深层诵读困难的功能成像研究的支持，但尚未有关于发育性深层诵读困难病例的成像研究报告，此类病例不存在脑损伤嫌疑。在本文中，我们报告了一例成年发育性深层诵读困难病例中右脑过度激活的首个证据。在对可想象内容词和非词进行口头阅读的功能磁共振成像（fMRI）过程中，观察到右下额叶皮质出现过度激活，这些词和非词常引发可想象的词汇反应。在功能词的口头阅读中，以及在对图片对象做出反应说出可想象单词的过程中，均未观察到右脑过度激活的证据。结果揭示了针对特定类型书面刺激对右脑半球功能的策略性和选择性运用。我们提出，发育性深层诵读困难儿童通过利用右脑半球可想象的联想来弥补其语音技能的不足，这些联想为将书面形式与口语名称联系起来提供了记忆方法。
