fMRI assessment of language lateralization: An objective approach
fMRI assessment of language lateralization: An objective approach
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DOI：
10.1016/j.neuroimage.2010.01.059
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发表时间：
2010-05-01
期刊：
影响因子：
5.7
通讯作者：
Jackson, Graeme D.
中科院分区：
文献类型：
--
作者：
Abbott, David F.;Waites, Anthony B.;Jackson, Graeme D.
基于功能磁共振成像（fMRI）的语言定侧常用于临床神经系统。目前，对语言激活的分布、模式和程度的解释在很大程度上取决于所选择的统计阈值。本研究的目的是1）测试功能磁共振成像数据的自适应阈值处理的鲁棒性，以产生固定数量的活动体素，并2）开发一个很大程度上阈值独立的方法来评估个体患者何时具有统计学上的非典型语言偏侧化。使用34名健康对照者和4名癫痫患者的模拟数据和真实的fMRI数据进行言语流畅性语言fMRI任务。模拟和真实的数据的阈值方法的偏侧性的依赖性证明。模拟数据用于检验以下假设：基于固定数量的活动体素的阈值处理将产生与固定p值下的阈值处理相比在信号强度（研究功效）范围内更稳定的偏侧性指数。这种稳定性允许开发一种方法，在广泛的阈值范围内将个体与一组对照进行比较，从而提供比传统方法更客观的非典型偏侧化的稳健指示。30名健康对照被用作阈值独立方法的标准数据，其余受试者被用作说明性示例。该方法还可以更普遍地用于评估其他神经成像范例中活动的相对区域分布（例如，可以将其应用于评估记忆任务中激活的偏侧化，或评估前后分布而不是偏侧化）。(C)2010年爱思唯尔公司All rights reserved.
Language lateralization based on functional magnetic resonance imaging (fMRI) is often used in clinical neurological settings. Currently, interpretation of the distribution, pattern and extent of language activation can be heavily dependent on the chosen statistical threshold. The aim of the present study was to 1) test the robustness of adaptive thresholding of fMRI data to yield a fixed number of active voxels, and to 2) develop a largely threshold-independent method of assessing when individual patients have statistically atypical language lateralization. Simulated data and real fMRI data in 34 healthy controls and 4 selected epilepsy patients performing a verbal fluency language fMRI task were used. Dependence of laterality on the thresholding method is demonstrated for simulated and real data. Simulated data were used to test the hypothesis that thresholding based upon a fixed number of active voxels would yield a laterality index that was more stable across a range of signal strengths (study power) compared to thresholding at a fixed p value. This stability allowed development of a method comparing an individual to a group of controls across a wide range of thresholds, providing a robust indication of atypical lateralization that is more objective than conventional methods. Thirty healthy controls were used as normative data for the threshold-independent method, and the remaining subjects were used as illustrative examples. The method could also be used more generally to assess relative regional distribution of activity in other neuroimaging paradigms (for example, one could apply it to the assessment of lateralization of activation in a memory task, or to the assessment of anterior-posterior distribution rather than laterality). (C) 2010 Elsevier Inc. All rights reserved.