Wilson Alexander C, Bishop Dorothy V M
Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom.
PeerJ. 2018 Jan 8;6:e4217. doi: 10.7717/peerj.4217. eCollection 2018.
It has been suggested that failure to establish cerebral lateralisation may be related to developmental language disorder (DLD). There has been weak support for any link with handedness, but more consistent reports of associations with functional brain lateralisation for language. The consistency of lateralisation across different functions may also be important. We aimed to replicate previous findings of an association between DLD and reduced laterality on a quantitative measure of hand preference (reaching across the midline) and on language laterality assessed using functional transcranial Doppler ultrasound (fTCD).
From a sample of twin children aged from 6;0 to 11;11 years, we identified 107 cases of DLD and 156 typically-developing comparison cases for whom we had useable data from fTCD yielding a laterality index (LI) for language function during an animation description task. Handedness data were also available for these children.
Indices of handedness and language laterality for this twin sample were similar to those previously reported for single-born children. There were no differences between the DLD and TD groups on measures of handedness or language lateralisation, or on a categorical measure of consistency of left hemisphere dominance. Contrary to prediction, there was a greater incidence of right lateralisation for language in the TD group (19.90%) than the DLD group (9.30%), confirming that atypical laterality is not inconsistent with typical language development. We also failed to replicate associations between language laterality and language test scores.
Given the large sample studied here and the range of measures, we suggest that previous reports of atypical manual or language lateralisation in DLD may have been false positives.
有人提出，未能建立大脑半球偏侧化可能与发育性语言障碍（DLD）有关。虽然与利手之间的联系支持较弱，但关于与语言功能脑偏侧化的关联报道更为一致。不同功能间偏侧化的一致性可能也很重要。我们旨在通过对伸手过中线这一手偏好的定量测量以及使用功能性经颅多普勒超声（fTCD）评估的语言偏侧化，来重复先前关于DLD与偏侧化降低之间关联的研究结果。
从6岁0个月至11岁11个月的双胞胎儿童样本中，我们确定了107例DLD病例和156例发育正常的对照病例，我们有这些病例在动画描述任务期间来自fTCD的可用数据，可得出语言功能的偏侧化指数（LI）。这些儿童也有关于利手的数据。
这个双胞胎样本的利手和语言偏侧化指数与先前报道的单胎儿童相似。在利手或语言偏侧化测量方面，以及在左半球优势一致性的分类测量方面，DLD组和发育正常组之间没有差异。与预测相反，发育正常组（19.90%）语言右偏侧化的发生率高于DLD组（9.30%），这证实了非典型偏侧化与典型语言发展并不矛盾。我们也未能重复语言偏侧化与语言测试分数之间的关联。
鉴于这里研究的样本量大且测量范围广，我们认为先前关于DLD中非典型手部或语言偏侧化的报道可能是假阳性。
