Language Development Department, Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands.
Department of Linguistic, Literary and Aesthetic Studies, University of Bergen, Bergen, Norway.
Neuroimage. 2024 Sep;298:120786. doi: 10.1016/j.neuroimage.2024.120786. Epub 2024 Aug 13.
The present study uses electroencephalography (EEG) with an N-back task (0-, 1-, and 2-back) to investigate if and how individual bilingual experiences modulate brain activity and cognitive processes. The N-back is an especially appropriate task given recent proposals situating bilingual effects on neurocognition within the broader attentional control system (Bialystok and Craik, 2022). Beyond its working memory component, the N-Back task builds in complexity incrementally, progressively taxing the attentional system. EEG, behavioral and language/social background data were collected from 60 bilinguals. Two cognitive loads were calculated: low (1-back minus 0-back) and high (2-back minus 0-back). Behavioral performance and brain recruitment were modeled as a function of individual differences in bilingual engagement. We predicted task performance as modulated by bilingual engagement would reflect cognitive demands of increased complexity: slower reaction times and lower accuracy, and increase in theta, decrease in alpha and modulated N2/P3 amplitudes. The data show no modulation of the expected behavioral effects by degree of bilingual engagement. However, individual differences analyses reveal significant correlations between non-societal language use in Social contexts and alpha in the low cognitive load condition and age of acquisition of the L2/2L1 with theta in the high cognitive load. These findings lend some initial support to Bialystok and Craik (2022), showing how certain adaptations at the brain level take place in order to deal with the cognitive demands associated with variations in bilingual language experience and increases in attentional load. Furthermore, the present data highlight how these effects can play out differentially depending on cognitive testing/modalities - that is, effects were found at the TFR level but not behaviorally or in the ERPs, showing how the choice of analysis can be deterministic when investigating bilingual effects.
本研究使用脑电图 (EEG) 结合 N 回任务（0-、1-和 2-回）来探究个体双语经验是否以及如何调节大脑活动和认知过程。鉴于最近有研究将双语效应置于更广泛的注意控制系统（Bialystok 和 Craik，2022）内，N 回任务是一个特别合适的任务。除了工作记忆成分外，N 回任务的复杂度逐渐增加，逐渐增加注意力系统的负担。从 60 名双语者那里收集了 EEG、行为和语言/社会背景数据。计算了两个认知负荷：低（1 回减 0 回）和高（2 回减 0 回）。将行为表现和大脑募集作为个体双语参与差异的函数进行建模。我们预测，双语参与调节的任务表现将反映出复杂性增加的认知需求：反应时间变慢、准确性降低，θ 增加，α 减少，N2/P3 振幅调制。数据显示，双语参与程度没有调节预期的行为效应。然而，个体差异分析显示，社会语境下非社会语言使用与低认知负荷条件下的α以及第二语言/双语习得年龄与高认知负荷条件下的θ之间存在显著相关性。这些发现初步支持了 Bialystok 和 Craik（2022）的观点，表明大脑水平上的某些适应是如何为了应对与双语语言经验变化和注意力负荷增加相关的认知需求而发生的。此外，本研究数据突出了这些效应如何根据认知测试/模式而产生不同的影响——即，在 TFR 水平上发现了效应，但在行为或 ERP 上没有发现效应，表明在调查双语效应时，分析的选择可能具有决定性。
