Wilson Stephen M
Department of Speech, Language, and Hearing Sciences, University of Arizona, Tucson, Arizona; Department of Neurology, University of Arizona, Tucson, Arizona.
Hum Brain Mapp. 2014 Aug;35(8):4049-63. doi: 10.1002/hbm.22457. Epub 2014 Jan 22.
The left superior temporal sulcus (STS) has been shown in numerous functional imaging studies to be a critical region for language processing, as it is reliably activated when language comprehension is compared with acoustically matched control conditions. Studies in non-human primates have demonstrated several subdivisions in the STS, yet the precise region(s) within the STS that are important for language remain unclear, in large part because the presence of draining veins in the sulcus makes it difficult to determine whether neural activity is localized to the dorsal or ventral bank of the sulcus. We used functional MRI to localize language regions, and then acquired several additional sequences in order to account for the impact of vascular factors. A breath-holding task was used to induce hypercapnia in order to normalize voxel-wise differences in blood oxygen level-dependent (BOLD) responsivity, and veins were identified on susceptibility-weighted and T2*-weighted BOLD images, and masked out. We found that the precise locations of language areas in individual participants were strongly influenced by vascular factors, but that these vascular effects could be ameliorated by hypercapnic normalization and vein masking. After these corrections were applied, the majority of regions activated by language processing were localized to the dorsal bank of the STS.
在众多功能成像研究中，左侧颞上沟（STS）已被证明是语言处理的关键区域，因为与声学匹配的对照条件相比，在语言理解时它会可靠地被激活。对非人类灵长类动物的研究已经证明了颞上沟存在几个亚区，但颞上沟内对语言重要的精确区域仍不清楚，很大程度上是因为沟内引流静脉的存在使得难以确定神经活动是局限于沟的背侧还是腹侧。我们使用功能磁共振成像来定位语言区域，然后获取了几个额外的序列以考虑血管因素的影响。使用屏气任务诱导高碳酸血症，以标准化血氧水平依赖（BOLD）反应性的体素差异，并在敏感性加权和T2 *加权BOLD图像上识别静脉并将其掩盖。我们发现个体参与者中语言区域的精确位置受到血管因素的强烈影响，但这些血管效应可以通过高碳酸血症标准化和静脉掩盖来改善。应用这些校正后，大多数由语言处理激活的区域位于颞上沟的背侧。
