VA Northern California Health Care System, Martinez, CA 94553, USA.
Cortex. 2011 Jul-Aug;47(7):800-7. doi: 10.1016/j.cortex.2010.07.001. Epub 2010 Aug 6.
Previous research has suggested that the left anterior insula, specifically the superior precentral gyrus of the insula (SPGI), is a critical brain region for the coordination of complex articulatory movements. However, previous studies have not determined which articulatory factors are specifically dependent on this brain region. In the current study, 33 left hemisphere stroke patients with varying degrees of speech impairment were asked to perform multiple repetitions of single words that varied along three separate dimensions: number of syllables, degree of articulatory travel (i.e., change between places of articulation for consonants), and presence/absence of an initial consonant cluster. The role of the SPGI in performance across the three conditions was determined using voxel-based lesion symptom mapping (VLSM), a statistical approach to lesion analysis that does not require separating patients based on lesion site or symptom profile. Rather, continuous performance data are entered, along with lesions reconstructed in normalized space. Based on preliminary analyses, there was adequate power to detect differences in the SPGI, which was the focus of our predictions. We found that the SPGI was critical for performance on the articulation task across all three conditions, namely, when words were multi-syllabic, required a high degree of travel, or involved an initial consonant cluster. As a control, we also generated a VLSM map for articulation of words with minimal articulatory complexity (i.e., single-syllable words with no initial cluster and a minimal change in place of articulation). In this case, the SPGI was not implicated. The current results suggest that the left SPGI is a critical area for intra- and inter-syllabic coordination of complex articulatory movements, prior to end-stage execution of speech commands.
先前的研究表明，左侧前脑岛，特别是脑岛的上中央前回（SPGI），是协调复杂发音运动的关键脑区。然而，先前的研究尚未确定哪些发音因素特别依赖于这个脑区。在当前的研究中，我们要求 33 名左侧半球中风患者重复说出多种单音节词，这些单词在三个不同的维度上变化：音节数、发音运动程度（即，辅音发音部位的变化），以及是否存在初始辅音群。使用基于体素的病变症状映射（VLSM）来确定 SPGI 在这三种条件下的表现作用，这是一种病变分析的统计方法，不需要根据病变部位或症状特征来分离患者。相反，连续的表现数据与在归一化空间中重建的病变一起输入。基于初步分析，我们有足够的能力来检测 SPGI 中的差异，这是我们预测的重点。我们发现，SPGI 对于三种条件下的发音任务表现都至关重要，即当单词是多音节的、需要高度运动或涉及初始辅音群时。作为对照，我们还为发音复杂性最小的单词（即，没有初始辅音群且发音部位变化最小的单音节词）生成了一个 VLSM 图。在这种情况下，SPGI 不被涉及。当前的结果表明，左侧 SPGI 是在执行言语命令之前协调复杂发音运动的内在和音节间协调的关键区域。
