Functional characterisation of letter-specific responses in time, space and current polarity using magnetoencephalography
Functional characterisation of letter-specific responses in time, space and current polarity using magnetoencephalography
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DOI：
10.1016/j.neuroimage.2016.02.057
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发表时间：
2016-05-15
期刊：
影响因子：
5.7
通讯作者：
Marantz, A.
中科院分区：
文献类型：
--
作者：
Gwilliams, L.;Lewis, G. A.;Marantz, A.
最近的神经生理学证据表明，一个由低到高的层次神经网络处理有助于书面语言的理解。虽然相当多的研究已经确定了不同的区域和阶段的处理，它们之间的关系，这一层次模型仍然不清楚。脑磁图（MEG）是一种经常用于此类研究的技术;然而，没有研究试图测试在磁场源处重建电流的传统方法是否最适合于此类跨学科设计。本研究详细介绍了三个MEG实验解决这些问题的结果。神经元群体支持响应低级别的正交属性被安置在后方附近的初级视觉皮层。更多的前部区域沿着梭状回编码更高级别的过程，并成为活跃的类似80毫秒后。这些早期的字母特异性反应的功能定位器的开发，在未来的研究中感兴趣的功能区域的生产。先前建立的响应组件成功地分组的基础上接近定位器，其特征在于位置，延迟和功能灵敏度。非传统的解剖约束签署最小范数估计的MEG数据是最敏感的主要实验操作，这表明传统的无符号无约束的方法是次优的研究书面文字处理。(C)2016作者爱思唯尔公司出版
Recent neurophysiological evidence suggests that a hierarchical neural network of low-to-high level processing subserves written language comprehension. While a considerable amount of research has identified distinct regions and stages of processing, the relations between them and to this hierarchical model remain unclear. Magnetoencephalography (MEG) is a technique frequently employed in such investigations; however, no studies have sought to test whether the conventional method of reconstructing currents at the source of the magnetic field is best suited for such across-subject designs. The present study details the results of three MEG experiments addressing these issues. Neuronal populations supporting responses to low-level orthographic properties were housed posteriorly near the primary visual cortex. More anterior regions along the fusiform gyrus encoded higher-level processes and became active similar to 80 ms later. A functional localiser of these early letter-specific responses was developed for the production of functional regions of interest in future studies. Previously established response components were successfully grouped based on proximity to the localiser, which characterised location, latency and functional sensitivity. Unconventional anatomically constrained signed minimum norm estimates of MEG data were most sensitive to the primary experimental manipulation, suggesting that the conventional unsigned unconstrained method is sub-optimal for studying written word processing. (C) 2016 The Authors. Published by Elsevier Inc.