Effects of genetic differences and bilingual status on cognitive control

 描述：该项目旨在研究语言状态和遗传变异与认知控制之间的关系。为了实现这一目标，拟议的项目将使用功能磁共振成像(FMRI)，它测量脱氧血红蛋白，与血流和能量代谢相关，并作为神经活动的间接测量。包括我们自己在内的许多实验室的研究发现，在认知控制任务中，双语者和单语者的神经和行为存在差异。此外，最近的研究表明，在双语人群中，有言语反应和没有明确言语反应的控制任务的执行能力存在差异。最后，一项独立的研究发现，对于DRD2/ANKK1 Taq1A多态的A1等位基因携带者来说，在没有明确言语反应的情况下切换任务具有优势。这些人的多巴胺D2受体数量减少，转换成本降低，专用于认知控制的神经区域的活动减少。第二项使用DRD2激动剂的研究发现，与安慰剂相比，激动剂条件下相同区域的开关相关激活增加。在这项拟议的研究中，将对一组双语者和单语者进行基因构成筛查。在执行认知控制任务时，每组中作为携带者或非携带者的子集将被放置在核磁共振扫描仪中。拟议的研究结果将有助于阐明A1等位基因携带者在单语和双语人群中的表现是否优于非携带者。它还将阐明双语者的优势是否会受到群体遗传状况的影响。因此，它应该成为未来儿童学习第二语言的跳板。这一结果还可能阐明双语的理论解释，并通过揭示基因变异是否也与认知控制任务的表现相关，为研究双语者的临床医生和教育工作者提供参考。

 DESCRIPTION: The proposed project is designed to investigate how language status and genetic variation is associated with cognitive control. To achieve this, the proposed project will use functional Magnetic Resonance Imaging (fMRI), which measures deoxyhemoglobin, is correlated with blood flow and energy metabolism, and serves as an indirect measure of neural activity. Work in many laboratories including our own has identified neural and behavioral differences in bilinguals and monolinguals during cognitive control tasks. Furthermore, recent studies suggest that differences in the ability to perform control tasks with verbal and no explici verbal response exist within the bilingual population. Finally, an independent study found an advantage on switching tasks with no explicit verbal response for carriers of the A1 allele of the DRD2/ANKK1 taq1A polymorphism. These individuals have a reduced number of dopamine D2 receptors, show a decrease in switching costs, and have decreased activity in neural areas devoted to cognitive control. A second study using a DRD2 agonist, found increased switching-related activation in the same areas in the agonist condition compared to placebo. In the proposed study, a group of bilinguals and monolinguals will be screened for their genetic makeup. From these a subset of each group that is a carrier or not will be placed in an MRI scanner while performing a cognitive control task. The results from the proposed study will help to elucidate whether carriers of the A1 allele outperform non-carriers in both monolingual and bilingual populations. It will also elucidate whether the magnitude of any advantage seen in bilinguals is moderated by a group's genetic status. As such it should serve as the springboard for future studies with children learning a second language. The results may also shed light on theoretical accounts of bilingualism as well as inform clinicians and educators who work with bilinguals by revealing whether genetic variation is also associated with performance on cognitive control tasks.