Kurland Jacquie, Cortes Carlos R, Wilke Marko, Sperling Anne J, Lott Susan N, Tagamets Malle A, Vanmeter John, Friedman Rhonda B
Department of Neurology, Georgetown University Medical Center (GUMC), Washington, DC.
Brain Imaging Behav. 2008 Sep;2(3):147. doi: 10.1007/s11682-008-9027-2.
Patients with phonologic alexia can be trained to read semantically impoverished words (e.g., functors) by pairing them with phonologically-related semantically rich words (e.g, nouns). What mechanisms underlie success in this cognitive re-training approach? Does the mechanism change if the skill is "overlearned", i.e., practiced beyond criterion? We utilized fMRI pre- and post-treatment, and after overlearning, to assess treatment-related functional reorganization in a patient with phonologic alexia, two years post left temporoparietal stroke. Pre-treatment, there were no statistically significant differences in activation profiles across the sets of words. Post-treatment, accuracy on the two trained sets improved. Compared with untrained words, reading trained words recruited larger and more significant clusters of activation in the right hemisphere, including right inferior frontal and inferior parietal cortex. Post-overlearning, with near normal performance on overlearned words, predominant activation shifted to left hemisphere regions, including perilesional activation in superior parietal lobe, when reading overlearned vs. untrained words.
语音性失读症患者可以通过将语义贫乏的单词（如功能词）与语音相关且语义丰富的单词（如名词）配对来训练阅读这些单词。这种认知再训练方法成功的背后有哪些机制？如果技能被“过度学习”，即练习超过了标准，机制会改变吗？我们利用功能性磁共振成像（fMRI）在治疗前、治疗后以及过度学习后，对一名左侧颞顶叶中风两年后的语音性失读症患者进行评估，以确定与治疗相关的功能重组情况。治疗前，各组单词的激活模式没有统计学上的显著差异。治疗后，两组训练单词的准确率提高。与未训练的单词相比，阅读训练过的单词时，右半球激活的区域更大且更显著，包括右下额叶和下顶叶皮质。过度学习后，在过度学习的单词上表现接近正常，阅读过度学习的单词与未训练的单词相比，主要激活区域转移到了左半球区域，包括顶上叶的病灶周围激活。
