Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Proc Natl Acad Sci U S A. 2009 Dec 1;106(48):20499-503. doi: 10.1073/pnas.0908073106. Epub 2009 Nov 16.
Cerebral lateralization is a fundamental property of the human brain and a marker of successful development. Here we provide evidence that multiple mechanisms control asymmetry for distinct brain systems. Using intrinsic activity to measure asymmetry in 300 adults, we mapped the most strongly lateralized brain regions. Both men and women showed strong asymmetries with a significant, but small, group difference. Factor analysis on the asymmetric regions revealed 4 separate factors that each accounted for significant variation across subjects. The factors were associated with brain systems involved in vision, internal thought (the default network), attention, and language. An independent sample of right- and left-handed individuals showed that hand dominance affects brain asymmetry but differentially across the 4 factors supporting their independence. These findings show the feasibility of measuring brain asymmetry using intrinsic activity fluctuations and suggest that multiple genetic or environmental mechanisms control cerebral lateralization.
大脑偏侧化是人类大脑的基本属性，也是成功发育的标志。在这里，我们提供证据表明，多个机制控制着不同大脑系统的不对称性。我们使用固有活动来测量 300 名成年人的不对称性，绘制了最强烈偏侧化的大脑区域。男性和女性都表现出强烈的不对称性，且存在显著但很小的组间差异。对不对称区域的因子分析揭示了 4 个独立的因子，每个因子在受试者之间都有显著的差异。这些因子与涉及视觉、内部思维（默认网络）、注意力和语言的大脑系统有关。对右利手和左利手个体的独立样本显示，惯用手的使用会影响大脑的不对称性，但在支持其独立性的 4 个因子上的影响不同。这些发现表明，使用固有活动波动来测量大脑的不对称性是可行的，并表明多个遗传或环境机制控制着大脑的偏侧化。
