Can the Language-dominant Hemisphere Be Predicted by Brain Anatomy?
Can the Language-dominant Hemisphere Be Predicted by Brain Anatomy?
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DOI：
10.1162/jocn.2010.21563
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发表时间：
2011-08-01
影响因子：
3.2
通讯作者：
Deppe, Michael
中科院分区：
文献类型：
--
作者：
Keller, Simon S.;Roberts, Neil;Deppe, Michael
长期以来，人们一直怀疑皮质半球间的不对称可能是半球语言优势（HLD）的基础。为了检验这一假设，我们使用体视学和 MRI 确定了健康成人中与 HLD 相关的三个皮质区域（布罗卡区、颞平面和岛叶）的半球间不对称性，其中 HLD 是使用功能性经颅多普勒超声检查和功能 MRI 确定的（15 个左侧 HLD，10 个右侧 HLD）。我们观察到布罗卡区或颞平面的回旋相关体的体积不对称性与 HLD 之间没有关系。然而，我们观察到岛叶体积不对称性与 HLD 之间存在密切关系 (p = .008)，这预测 88% 的个体患有单侧 HLD（86.7% 为左侧 HDL，90% 为右侧 HLD）。 HLD 的程度和岛叶体积不对称性之间也存在微妙但显着的正相关性 (p = .02)，表明较大的岛叶预示着大多数受试者的功能偏侧化到同一半球一侧。我们没有发现 HLD 基本解剖标志的视觉证据，除了右侧 HLD 受试者的右后外侧裂终止更有可能是垂直的而不是水平的 (p = .02)。凭借大脑大体解剖学来预测 HLD 由于脑沟轮廓的个体差异而变得复杂，并且当分析不受脑回体积测量所施加的自然限制的约束时，古典语言区域的形态和细胞结构组织可能是 HLD 的基础。尽管 HLD 的解剖相关性很可能包括复杂的半球内和半球间连接，但这种连接有可能与灰质形态相关。我们建议，在未来研究人类语言偏侧化的解剖学相关性时，应考虑岛状形态的潜在意义。
It has long been suspected that cortical interhemispheric asymmetries may underlie hemispheric language dominance (HLD). To test this hypothesis, we determined interhemispheric asymmetries using stereology and MRI of three cortical regions hypothesized to be related to HLD (Broca's area, planum temporale, and insula) in healthy adults in whom HLD was determined using functional transcranial Doppler sonography and functional MRI (15 left HLD, 10 right HLD). We observed no relationship between volume asymmetry of the gyral correlates of Broca's area or planum temporale and HLD. However, we observed a robust relationship between volume asymmetry of the insula and HLD (p = .008), which predicted unilateral HLD in 88% individuals (86.7% left HDL and 90% right HLD). There was also a subtle but significant positive correlation between the extent of HLD and insula volume asymmetry (p = .02), indicating that a larger insula predicted functional lateralization to the same hemispheric side for the majority of subjects. We found no visual evidence of basic anatomical markers of HLD other than that the termination of the right posterior sylvian fissure was more likely to be vertical than horizontal in right HLD subjects (p = .02). Predicting HLD by virtue of gross brain anatomy is complicated by interindividual variability in sulcal contours, and the possibility remains that morphological and cytoarchitectural organization of the classical language regions may underlie HLD when analyses are not constrained by the natural limits imposed by measurement of gyral volume. Although the anatomical correlates of HLD will most likely be found to include complex intra-and interhemispheric connections, there is the possibility that such connectivity may correlate with gray matter morphology. We suggest that the potential significance of insular morphology should be considered in future studies addressing the anatomical correlates of human language lateralization.