A functional neuroimaging description of two deep dyslexic patients
A functional neuroimaging description of two deep dyslexic patients
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DOI：
10.1162/089892998562753
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发表时间：
1998-05-01
影响因子：
3.2
通讯作者：
Frackowiak, RSJ
中科院分区：
文献类型：
--
作者：
Price, CJ;Howard, D;Frackowiak, RSJ
深度阅读障碍是一种显著的阅读障碍，由左半球脑损伤引起，其特征是在大声阅读单个单词时出现语义错误（例如，阅读精神如威士忌）。对这种综合征有两种解释。一种是，深度阅读障碍是由于左半球残留的阅读系统失去了在不考虑意义的情况下发音的能力。第二，深度阅读障碍反映了右半球的文字处理。虽然以前的尝试，这些假设之间的裁决一直是不确定的，争议现在可以解决映射功能解剖。在这项研究中，我们证明，阅读的两个深度睡眠障碍患者（CJ和JG）涉及正常或增强活动与命名（布罗卡区和左后下颞叶皮层）和单词的含义（左后颞顶叶皮层和左前颞叶皮层）的备用左半球区域。在这些区域的右半球同源物中，正常组内和深度睡眠障碍患者之间的激活不一致。一个（CJ）在右前下颞叶皮层显示出增强的活动（相对于正常人），另一个（JG）在右布罗卡区，两个都在右额盖。虽然这些差异性的右半球激活可能影响了患者的阅读行为，但它们的激活模式主要反映了左半球备用区域的语义和语音系统。这些结果排除了纯粹用右半球文字处理来解释深度阅读障碍。
Deep dyslexia is a striking reading disorder that results from left-hemisphere brain damage and is characterized by semantic errors in reading single words aloud (e.g., reading spirit as whisky). Two types of explanation for this syndrome have been advanced. One is that deep dyslexia results from a residual left-hemisphere reading system that has lost the ability to pronounce a printed word without reference to meaning. The second is that deep dyslexia reflects right-hemisphere word processing. Although previous attempts to adjudicate between these hypotheses have been inconclusive, the controversy can now be addressed by mapping functional anatomy. In this study, we demonstrate that reading by two deep dyslexic patients (CJ and JG) involves normal or enhanced activity in spared left-hemisphere regions associated with naming (Broca's area and the left posterior inferior temporal cortex) and with the meanings of words (the left posterior temporo-parietal cortex and the left anterior temporal cortex). In the right-hemisphere homologues of these regions, there was inconsistent activation within the normal group and between the deep dyslexic patients. One (CJ) showed enhanced activity (relative to the normals) in the right anterior inferior temporal cortex, the other (JG) in the right Broca's area, and both in the right frontal operculum. Although these differential right-hemisphere activations may have influenced the reading behavior of the patients, their activation patterns primarily reflect semantic and phonological systems in spared regions of the left hemisphere. These results preclude an explanation of deep dyslexia in terms of purely right-hemisphere word processing.