Bosma Evelyn, Hoekstra Eric, Versloot Arjen, Blom Elma
Fryske Akademy, Royal Netherlands Academy of Arts and SciencesLeeuwarden, Netherlands.
Amsterdam Center for Language and Communication, University of AmsterdamAmsterdam, Netherlands.
Front Psychol. 2017 Aug 29;8:1453. doi: 10.3389/fpsyg.2017.01453. eCollection 2017.
Various studies have shown that bilingual children need a certain degree of proficiency in both languages before their bilingual experiences enhance their executive functioning (EF). In the current study, we investigated if degree of bilingualism in Frisian-Dutch children influenced EF and if this effect was sustained over a 3-year period. To this end, longitudinal data were analyzed from 120 Frisian-Dutch bilingual children who were 5- or 6-years-old at the first time of testing. EF was measured with two attention and two working memory tasks. Degree of bilingualism was defined as language balance based on receptive vocabulary and expressive morphology scores in both languages. In a context with a minority and a majority language, such as the Frisian-Dutch context, chances for becoming proficient in both languages are best for children who speak the minority language at home. Therefore, in a subsequent analysis, we examined whether minority language exposure predicted language balance and whether there was a relationship between minority language exposure and EF, mediated by language balance. The results showed that intensity of exposure to Frisian at home, mediated by language balance, had an impact on one of the attention tasks only. It predicted performance on this task at time 1, but not at time 2 and 3. This partially confirms previous evidence that the cognitive effects of bilingualism are moderated by degree of bilingualism and furthermore reveals that substantial minority language exposure at home indirectly affects bilingual children's cognitive development, namely through mediation with degree of bilingualism. However, the findings also demonstrate that the effect of bilingualism on EF is limited and unstable.
多项研究表明，双语儿童在其双语经历增强其执行功能（EF）之前，需要在两种语言上都具备一定程度的熟练程度。在本研究中，我们调查了弗里斯兰语 - 荷兰语双语儿童的双语程度是否会影响执行功能，以及这种影响是否会在三年期间持续存在。为此，我们分析了120名弗里斯兰语 - 荷兰语双语儿童的纵向数据，这些儿童在首次测试时年龄为5岁或6岁。执行功能通过两项注意力任务和两项工作记忆任务进行测量。双语程度根据两种语言中接受性词汇和表达形态学得分定义为语言平衡。在一种存在少数民族语言和多数民族语言的环境中，例如弗里斯兰语 - 荷兰语环境，对于在家说少数民族语言的儿童来说，精通两种语言的机会最大。因此，在后续分析中，我们研究了接触少数民族语言是否能预测语言平衡，以及在语言平衡的中介作用下，接触少数民族语言与执行功能之间是否存在关系。结果表明，在家接触弗里斯兰语的强度，通过语言平衡起中介作用，仅对其中一项注意力任务有影响。它预测了在时间1时该任务的表现，但在时间2和3时则不然。这部分证实了先前的证据，即双语的认知效果受双语程度的调节，并且进一步揭示了在家大量接触少数民族语言会间接影响双语儿童的认知发展，即通过与双语程度的中介作用。然而，研究结果也表明，双语对执行功能的影响是有限且不稳定的。
