James Karin H, Gauthier Isabel
Department of Psychological and Brain Sciences, Indiana University, 1101 E. 10th Street, Bloomington, IN 47405, USA.
Neuropsychologia. 2006;44(14):2937-49. doi: 10.1016/j.neuropsychologia.2006.06.026. Epub 2006 Aug 22.
Behavioral, neuropsychological and neuroimaging research suggest a distributed network that is recruited when we interact with letters. For the first time, we combine several letter processing tasks in a single experiment to study why letters seem to engage such disparate processing areas. Using fMRI, we investigate how the brain responds to letters using tasks that should recruit systems for letter perception, letter writing, letter copying and letter imagery. We describe a network of five cortical regions including the left fusiform gyrus, two left pre-central areas, left cuneus and the left inferior frontal gyrus that are all selectively engaged during a 1-back matching paradigm with letters. Our results suggest involvement of these regions to different extents in different tasks. However, the regions also form an integrated network such that letter perception also engages motor regions while writing recruits letter-specific visual regions as well. We suggest that this distributed network is a direct result of our sensory-motor interactions with letters.
行为学、神经心理学和神经影像学研究表明，当我们与字母互动时，会激活一个分布式网络。我们首次在一个实验中结合了多个字母处理任务，以研究为何字母似乎会涉及如此不同的处理区域。利用功能磁共振成像（fMRI），我们通过一些任务来研究大脑如何对字母做出反应，这些任务应该会激活用于字母感知、字母书写、字母抄写和字母想象的系统。我们描述了一个由五个皮质区域组成的网络，包括左侧梭状回、两个左侧中央前区、左侧楔叶和左侧额下回，在字母的1-back匹配范式中，这些区域均被选择性激活。我们的结果表明，这些区域在不同任务中不同程度地参与其中。然而，这些区域也形成了一个整合网络，使得字母感知也会激活运动区域，而书写时也会激活特定于字母的视觉区域。我们认为，这个分布式网络是我们与字母进行感觉运动交互的直接结果。
