Department ofNeurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
J Cogn Neurosci. 2011 Jun;23(6):1475-93. doi: 10.1162/jocn.2010.21515. Epub 2010 Apr 30.
In a previous study of single word reading, regions in the left supramarginal gyrus and left angular gyrus showed positive BOLD activity in children but significantly less activity in adults for high-frequency words [Church, J. A., Coalson, R. S., Lugar, H. M., Petersen, S. E., & Schlaggar, B. L. A developmental fMRI study of reading and repetition reveals changes in phonological and visual mechanisms over age. Cerebral Cortex, 18, 2054-2065, 2008]. This developmental decrease may reflect decreased reliance on phonological processing for familiar stimuli in adults. Therefore, in the present study, variables thought to influence phonological demand (string length and lexicality) were manipulated. Length and lexicality effects in the brain were explored using both ROI and whole-brain approaches. In the ROI analysis, the supramarginal and angular regions from the previous study were applied to this study. The supramarginal region showed a significant positive effect of length, consistent with a role in phonological processing, whereas the angular region showed only negative deflections from baseline with a strong effect of lexicality and other weaker effects. At the whole-brain level, varying effects of length and lexicality and their interactions were observed in 85 regions throughout the brain. The application of hierarchical clustering analysis to the BOLD time course data derived from these regions revealed seven clusters, with potentially revealing anatomical locations. Of note, a left angular gyrus region was the sole constituent of one cluster. Taken together, these findings in adult readers (1) provide support for a widespread set of brain regions affected by lexical variables, (2) corroborate a role for phonological processing in the left supramarginal gyrus, and (3) do not support a strong role for phonological processing in the left angular gyrus.
在之前关于单个单词阅读的研究中，左侧缘上回和左侧角回的区域在儿童中显示出正的 BOLD 活动，但在高频词中，成年人的活动明显减少[Church，JA，Coalson，RS，Lugar，HM，Petersen，SE，& Schlaggar，BL。一项关于阅读和重复的发展 fMRI 研究表明，随着年龄的增长，语音和视觉机制发生了变化。大脑皮层，18，2054-2065，2008]。这种发育性下降可能反映了成年人对熟悉刺激的语音处理依赖程度降低。因此，在本研究中，我们操纵了被认为会影响语音需求（字符串长度和词汇性）的变量。使用 ROI 和全脑方法探索了大脑中的长度和词汇性效应。在 ROI 分析中，应用了先前研究中的缘上回和角回区域。缘上回区域显示出长度的显著正效应，与语音处理的作用一致，而角回区域仅显示出与词汇性和其他较弱效应相反的基线负偏。在全脑水平上，观察到 85 个大脑区域中存在长度和词汇性及其相互作用的变化效应。对源自这些区域的 BOLD 时间序列数据进行分层聚类分析的应用揭示了七个具有潜在揭示解剖位置的聚类。值得注意的是，左侧角回区域是一个聚类的唯一组成部分。总之，这些成年读者的发现（1）为受词汇变量影响的广泛脑区提供了支持，（2）证实了语音处理在左侧缘上回中的作用，（3）不支持语音处理在左侧角回中的重要作用。
