In recent years there has been considerable debate about the presence or absence of a bilingual advantage in tasks that involve cognitive control. Our previous work has established evidence of differences in brain activity between monolinguals and bilinguals in both word learning and in the avoidance of interference during a picture selection task. Recent models of cognitive control have highlighted the importance of a set of neural structures that may show differential tuning due to exposure to two languages. There is also evidence that genetic factors play a role in the availability of dopamine in neural structures involved in cognitive control. Thus, it is important to investigate whether there are interactions effects generating variability in language acquisition when attributed to genetic (e.g., characteristics of dopamine turnover) and environmental (e.g., exposure to two languages) factors. Here preliminary results from genotyping of a sample of bilingual and monolingual individuals are reported. They reveal different distributions in allele frequencies of the DRD2/ANKK1 taq1A polymorphism. These results bring up the possibility that bilinguals may exhibit additional flexibility due to differences in genetic characteristics relative to monolinguals. Future studies should consider genotype as a possible contributing factor to the development of cognitive control across individuals with different language learning histories.

中文翻译：

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超越双语优势：基因和环境对认知控制发展的潜在作用

近年来，关于在涉及认知控制的任务中是否存在双语优势存在相当多的争论。我们之前的工作已经证明，单语者和双语者在单词学习和图片选择任务期间避免干扰方面的大脑活动存在差异。最近的认知控制模型强调了一组神经结构的重要性，这些神经结构可能会因接触两种语言而表现出差异调节。还有证据表明，遗传因素在参与认知控制的神经结构中多巴胺的可用性方面发挥着作用。因此，当归因于遗传（例如，多巴胺周转的特征）和环境（例如，接触两种语言）因素时，研究是否存在相互作用效应会产生语言习得的变异性是很重要的。这里报告了双语和单语个体样本基因分型的初步结果。它们揭示了 DRD2/ANKK1 taq1A 多态性等位基因频率的不同分布。这些结果表明，由于相对于单语者的遗传特征差异，双语者可能表现出额外的灵活性。未来的研究应将基因型视为具有不同语言学习历史的个体认知控制发展的可能影响因素。