Interdepartmental Neuroscience Program, Yale School of Medicine, New Haven, CT, USA.
Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA.
Neuroimage. 2022 May 15;252:119040. doi: 10.1016/j.neuroimage.2022.119040. Epub 2022 Mar 8.
Handedness influences differences in lateralization of language areas as well as dominance of motor and somatosensory cortices. However, differences in whole-brain functional connectivity (i.e., functional connectomes) due to handedness have been relatively understudied beyond pre-specified networks of interest. Here, we compared functional connectomes of left- and right-handed individuals at the whole brain level. We explored differences in functional connectivity of previously established regions of interest, and showed differences between primarily left- and primarily right-handed individuals in the motor, somatosensory, and language areas using functional connectivity. We then proceeded to investigate these differences in the whole brain and found that the functional connectivity of left- and right-handed individuals are not specific to networks of interest, but extend across every region of the brain. In particular, we found that connections between and within the cerebellum show distinct patterns of connectivity. To put these effects into context, we show that the effect sizes associated with handedness differences account for a similar amount of individual differences in the connectome as sex differences. Together these results shed light on regions of the brain beyond those traditionally explored that contribute to differences in the functional organization of left- and right-handed individuals and underscore that handedness effects are neurobiologically meaningful in addition to being statistically significant.
利手会影响语言区域的侧化以及运动和体感皮质的优势差异。然而，由于利手而导致的全脑功能连接（即功能连接组）的差异，除了预先指定的感兴趣网络之外，相对来说研究较少。在这里，我们在全脑水平上比较了左利手和右利手个体的功能连接组。我们探索了先前确定的感兴趣区域的功能连接差异，并通过功能连接显示了运动、体感和语言区域中主要左利手和主要右利手个体之间的差异。然后，我们继续在全脑范围内研究这些差异，发现左利手和右利手个体的功能连接不仅局限于感兴趣的网络，而是扩展到大脑的每个区域。特别是，我们发现小脑之间和内部的连接具有不同的连接模式。为了将这些影响置于上下文中，我们表明与利手差异相关的效应大小与性别差异在连接组中对个体差异的解释程度相似。这些结果揭示了大脑中除了传统上探索的区域之外，还有哪些区域对左利手和右利手个体的功能组织差异有贡献，并强调利手效应不仅具有统计学意义，而且在神经生物学上也有意义。
