Neuroimaging has tremendous potential for quantifying hemispheric specializations. However, the possibilities remain under-utilized, in part, given some of the complexities in quantifying any differences in a reliable, transparent fashion. A second issue with hemispheric asymmetries is that they are extremely one-sided in most people. This skew limits the generalisability of any findings to those participants with rarer forms of cerebral asymmetry. Here, we demonstrate usefulness of an approach developed by Wilke and Lidzba, (J Neurosci Meth, 163, 2007), which allows for threshold-independent estimates of cerebral asymmetry to be calculated in individual participants. We compared these estimates from two separate runs for three different cerebral asymmetries in the same participants. We circumvented the skewed nature of this type of data in two ways; first, we scanned a large number of non-right handed participants, and second, we included asymmetries that favour the right hemisphere in right handers, which we had reason to believe were less skewed than those related to speech and language. Verbal fluency and two visuoperceptual asymmetries were localized in a sample of 33 right handed and 60 non-right handed participants. Laterality indices (LIs), which quantify the direction and strength of an asymmetry, were calculated for BOLD activity relating to language, face perception, and body perception in each run separately. Run 1 - run 2 correlations were all statistically significant and surprisingly sizeable (r = 0.89 to r = 0.62), considering the relatively short amount of time on task within our particular localizers. This noteworthy success validates a number of useful ways that functional neuroimaging can be used to advance understanding of cerebral asymmetries.

中文翻译：

---

使用fMRI量化半球专业化的有效性和可靠性：来自左手和右手的三个不同大脑不对称性的证据。

神经成像在量化半球专长方面具有巨大潜力。但是，鉴于以可靠，透明的方式量化任何差异的某些复杂性，这种可能性仍未得到充分利用。半球不对称性的第二个问题是它们在大多数人中是极端极端的。这种偏斜将任何发现的普遍性限制在具有罕见形式的脑不对称性的参与者身上。在这里，我们证明了Wilke和Lidzba（J Neurosci Meth，163，2007）开发的方法的有用性，该方法允许在个体参与者中计算与阈值无关的大脑不对称性估计。我们比较了来自相同参与者的三个不同大脑不对称性的两次单独运行的估计值。我们通过两种方式规避了此类数据的偏斜性质：首先，我们扫描了大量非右撇子参与者，其次，我们在右撇子中包含了有利于右半球的不对称性，我们有理由认为这些不对称性要比与语音和语言相关的不对称性小。在33名右撇子和60名非右撇子参与者的样本中，口语流利度和两个视觉感受不对称性被定位。分别针对每次跑步中与语言，面部知觉和身体知觉相关的BOLD活动，计算了量化不对称方向和强度的横向指数（LIs）。考虑到在我们特定的本地化器中执行任务的时间相对较短，运行1-运行2的相关性在统计上都非常显着且令人惊讶（r = 0.89至r = 0.62）。