School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou, China.
Jiangsu Collaborative Innovation Center for Language Ability, Jiangsu Normal University, Xuzhou, China.
Eur J Neurosci. 2023 Mar;57(5):840-853. doi: 10.1111/ejn.15918. Epub 2023 Feb 1.
How speaking two languages affects executive functions has been a long-standing debate and the mechanisms underlying the observed cognitive advantages of bilingualism remain unspecified. Here, using multivariate pattern classification methods, we decoded spatial patterns of neural signals associated with Flanker task performance in mono-dialectal and bi-dialectal speakers of Chinese. While univariate approach to even-related potentials (ERPs) showed no between-group difference, decoding accuracy of ERPs was reduced in bi-dialectal as compared to mono-dialectal speakers in both congruent-neutral and incongruent-neutral classifications. There was no effect of bidialectalism, however, on decoding accuracy of alpha-band oscillations, an electrophysiological index implicated in inhibition. Behavioural data analysed using the Drift Diffusion Model (DDM) showed facilitating effects of bidialectalism on non-decision times but no effect on drift rates. These findings demonstrate that using two dialects on a daily basis enhances general attentional deployment rather than affecting specific component of executive functions such as inhibitory control. Given that the two dialects of Chinese differed almost exclusively in phonology, the bidialectalism effect was most likely motivated by resolving phonological competition at lexical processing level.
双语如何影响执行功能一直是一个长期存在的争论，而双语认知优势的潜在机制仍未明确。在这里，我们使用多元模式分类方法，对单语和双语汉语使用者在 Flanker 任务表现中与神经信号相关的空间模式进行解码。虽然单变量方法对事件相关电位（ERP）没有显示出组间差异，但在一致性-中性和不一致-中性分类中，双语者的 ERP 解码准确性比单语者低。然而，双语对 alpha 波段振荡的解码准确性没有影响，alpha 波段振荡是一种与抑制有关的电生理指标。使用 Drift Diffusion Model (DDM) 分析的行为数据显示，双语对非决策时间有促进作用，但对漂移率没有影响。这些发现表明，每天使用两种方言可以增强一般注意力的分配，而不是影响执行功能的特定组成部分，如抑制控制。由于汉语的两种方言几乎只在音韵上有所不同，因此双语的影响很可能是由于在词汇处理层面解决音韵竞争所致。
