Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, Utah, United States of America.
PLoS One. 2013 Aug 14;8(8):e71275. doi: 10.1371/journal.pone.0071275. eCollection 2013.
Lateralized brain regions subserve functions such as language and visuospatial processing. It has been conjectured that individuals may be left-brain dominant or right-brain dominant based on personality and cognitive style, but neuroimaging data has not provided clear evidence whether such phenotypic differences in the strength of left-dominant or right-dominant networks exist. We evaluated whether strongly lateralized connections covaried within the same individuals. Data were analyzed from publicly available resting state scans for 1011 individuals between the ages of 7 and 29. For each subject, functional lateralization was measured for each pair of 7266 regions covering the gray matter at 5-mm resolution as a difference in correlation before and after inverting images across the midsagittal plane. The difference in gray matter density between homotopic coordinates was used as a regressor to reduce the effect of structural asymmetries on functional lateralization. Nine left- and 11 right-lateralized hubs were identified as peaks in the degree map from the graph of significantly lateralized connections. The left-lateralized hubs included regions from the default mode network (medial prefrontal cortex, posterior cingulate cortex, and temporoparietal junction) and language regions (e.g., Broca Area and Wernicke Area), whereas the right-lateralized hubs included regions from the attention control network (e.g., lateral intraparietal sulcus, anterior insula, area MT, and frontal eye fields). Left- and right-lateralized hubs formed two separable networks of mutually lateralized regions. Connections involving only left- or only right-lateralized hubs showed positive correlation across subjects, but only for connections sharing a node. Lateralization of brain connections appears to be a local rather than global property of brain networks, and our data are not consistent with a whole-brain phenotype of greater "left-brained" or greater "right-brained" network strength across individuals. Small increases in lateralization with age were seen, but no differences in gender were observed.
大脑的侧化区域负责语言和视空间处理等功能。人们推测，个体可能基于个性和认知风格表现出左脑优势或右脑优势，但神经影像学数据并未提供明确证据表明，在左优势或右优势网络的强度方面存在这种表型差异。我们评估了相同个体中是否存在强烈侧化的连接。对年龄在 7 至 29 岁之间的 1011 名个体的公开静息态扫描数据进行了分析。对于每个个体，以 5 毫米的分辨率覆盖灰质的 7266 个区域的每一对的功能侧化都以在沿正中矢状面反转图像前后的相关性差异来测量。同型坐标之间的灰质密度差异被用作回归量，以减少结构不对称性对功能侧化的影响。在显著侧化连接的图的度图中，确定了 9 个左侧化和 11 个右侧化的中心作为峰值。左侧化的中心包括默认模式网络（内侧前额叶皮质、后扣带皮质和颞顶联合）和语言区域（例如，布罗卡区和韦尼克区）的区域，而右侧化的中心包括注意力控制网络（例如，外侧顶内沟、前岛叶、MT 区和额眼区）的区域。左侧化和右侧化的中心形成了两个相互侧化区域的可分离网络。仅涉及左侧化或仅涉及右侧化的中心的连接在跨个体中显示出正相关，但仅在共享节点的连接中。大脑连接的侧化似乎是大脑网络的局部而非全局特性，我们的数据与个体之间存在更强的“左脑”或更强的“右脑”网络强度的全脑表型不一致。随着年龄的增长，侧化有较小的增加，但在性别方面没有差异。
