Cheema Kulpreet, Lantz Nicole, Cummine Jacqueline
Department of Communication Sciences and Disorders, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Neuroreport. 2018 Mar 7;29(4):271-279. doi: 10.1097/WNR.0000000000000938.
Although the role of cortical structures in skilled and impaired reading has been the topic of considerable investigation, the contribution of subcortical structures to reading performance is less well understood. Here, we assess the role of the caudate, putamen, and thalamus in adults with and without reading impairment. Thirty-three individuals (19 skilled readers and 14 reading impaired individuals) participated in two functional MRI tasks: (a) silent reading of real words and (b) silent reading of nonwords. Percent signal change was calculated for each of the three structures by evaluating the signal change relative to the baseline (i.e. no task or fixation crosses), and response time was measured for each reading condition. We found that for skilled readers, activity in the putamen predicted behavioral performance for both real words and nonwords. In contrast, we found evidence for two subgroups of impaired readers: a positive caudate activity group and a negative caudate activity group. Interestingly, brain activity differentially predicted reading performance depending on whether individuals had positive or negative caudate activity. We discuss our findings in the context of developmental reading impairments, print-to-speech networks, and language processing in general.
尽管皮质结构在熟练阅读和阅读障碍中的作用一直是大量研究的主题，但人们对皮质下结构对阅读表现的贡献了解较少。在此，我们评估尾状核、壳核和丘脑在有阅读障碍和无阅读障碍成年人中的作用。33名个体（19名熟练阅读者和14名阅读障碍个体）参与了两项功能磁共振成像任务：（a）默读真实单词和（b）默读非单词。通过评估相对于基线（即无任务或注视十字）的信号变化，计算这三个结构中每个结构的信号变化百分比，并测量每种阅读条件下的反应时间。我们发现，对于熟练阅读者，壳核的活动可预测真实单词和非单词的行为表现。相比之下，我们发现阅读障碍者存在两个亚组的证据：尾状核活动阳性组和尾状核活动阴性组。有趣的是，根据个体尾状核活动是阳性还是阴性，大脑活动对阅读表现的预测存在差异。我们将在发育性阅读障碍、从印刷文字到语音的网络以及一般语言处理的背景下讨论我们的发现。
