Wilke Marko, Lidzba Karen, Staudt Martin, Buchenau Karin, Grodd Wolfgang, Krägeloh-Mann Ingeborg
Department of Pediatric Neurology and Developmental Medicine, Children's Hospital, Germany.
Neuroimage. 2006 Aug 1;32(1):400-10. doi: 10.1016/j.neuroimage.2006.03.012. Epub 2006 May 2.
Hemispheric dominance for language is an important issue in functional neuroimaging, particularly driven by efforts to overcome the need for the invasive Wada test, which is all the more pressing in children. Here, we aimed at developing new paradigms for functional magnetic resonance imaging (fMRI) for assessment of language dominance that can be used in younger children and allow for performance monitoring. Two new tasks (letter and animal task) were developed and compared to two reference tasks (synonyms and verb generation task) from the literature. Overall, 23 healthy children participated (13 boys, 10 girls, 10.2 +/- 2.5 years, range 6.1-15.3 years). Analysis was done using statistical nonparametrical mapping (SnPM2) on SPM2. Both reference tasks show activation in a number of left-frontal brain regions. The letter task induced a very localized activation in the left hemisphere's Broca's region, while not activating other frontal brain regions. Lateralization (as assessed in different anatomically and functionally defined regions) was consistent and strong. The animal task failed to activate frontal brain regions and was not suitable for assessing language dominance in children in this form. We conclude that while both reference tasks are useful for determining language dominance, they coactivate a number of task-related frontal areas not directly involved in language processing. Additionally, one task is not applicable in young children while the other does not allow performance monitoring. The letter task allows to selectively activate language areas in the dominant hemisphere and is applicable even in the very lowest age group amenable to fMRI investigations while still allowing performance monitoring. It may thus be a useful tool in assessing normal and pathological language organization.
语言的半球优势是功能神经影像学中的一个重要问题，尤其是在克服侵入性Wada测试必要性的努力推动下，这一问题在儿童中更为紧迫。在此，我们旨在开发用于功能磁共振成像（fMRI）的新范式，以评估语言优势，该范式可用于年幼儿童并允许进行表现监测。我们开发了两项新任务（字母和动物任务），并将其与文献中的两项参考任务（同义词和动词生成任务）进行比较。总体而言，23名健康儿童参与了研究（13名男孩，10名女孩，年龄10.2±2.5岁，范围6.1 - 15.3岁）。使用SPM2上的统计非参数映射（SnPM2）进行分析。两项参考任务均显示在多个左额叶脑区有激活。字母任务在左半球的布洛卡区引起了非常局部的激活，而未激活其他额叶脑区。在不同的解剖学和功能定义区域评估的偏侧化是一致且强烈的。动物任务未能激活额叶脑区，因此以这种形式不适用于评估儿童的语言优势。我们得出结论，虽然两项参考任务都有助于确定语言优势，但它们共同激活了许多与任务相关但不直接参与语言处理的额叶区域。此外，一项任务不适用于年幼儿童，而另一项任务则不允许进行表现监测。字母任务能够选择性地激活优势半球的语言区域，即使在适合进行fMRI研究的最低年龄组中也适用，同时仍允许进行表现监测。因此，它可能是评估正常和病理性语言组织的有用工具。
