Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Institute of Cognitive Psychology, Leiden University, Leiden, Netherlands.
Eur J Neurosci. 2024 Sep;60(5):4813-4829. doi: 10.1111/ejn.16466. Epub 2024 Jul 23.
Language control in bilingual speakers is thought to be implicated in effectively switching between languages, inhibiting the non-intended language, and continuously monitoring what to say and what has been said. It has been a matter of controversy concerning whether language control operates in a comparable manner to cognitive control processes in non-linguistic domains (domain-general) or if it is exclusive to language processing (domain-specific). As midfrontal theta oscillations have been considered as an index of cognitive control, examining whether a midfrontal theta effect is evident in tasks requiring bilingual control could bring new insights to the ongoing debate. To this end, we reanalysed the EEG data from two previous bilingual production studies where Dutch-English bilinguals named pictures based on colour cues. Specifically, we focused on three fundamental control processes in bilingual production: switching between languages, inhibition of the nontarget language, and monitoring of speech errors. Theta power increase was observed in switch trials compared to repeat trials, with a midfrontal scalp distribution. However, no theta power difference was observed in switch trials following a shorter sequence of same-language trials compared to a longer sequence, suggesting a missing modulation of inhibitory control. Similarly, increased midfrontal theta power was observed when participants failed to switch to the intended language compared to correct responses. Altogether, these findings tentatively support the involvement of domain-general cognitive control mechanisms in bilingual switching.
双语者的语言控制被认为涉及有效地在语言之间切换、抑制非目标语言以及持续监控要说什么和已经说了什么。语言控制是类似于非语言领域（领域一般性）的认知控制过程还是专门针对语言处理（领域特殊性）的，这一直是争议的问题。由于中前额θ振荡被认为是认知控制的一个指标，因此检查双语控制任务中是否存在中前额θ效应可能会为正在进行的争论带来新的见解。为此，我们重新分析了来自两项先前的双语产生研究的 EEG 数据，在这些研究中，荷兰语-英语双语者根据颜色提示命名图片。具体来说，我们专注于双语产生中的三个基本控制过程：在语言之间切换、抑制非目标语言和监控言语错误。与重复试验相比，在切换试验中观察到θ功率增加，且头皮分布在中前额。然而，与较长的同语言序列相比，在较短的同语言序列之后的切换试验中没有观察到θ功率差异，这表明抑制控制的调节缺失。同样，与正确反应相比，当参与者未能切换到目标语言时，中前额θ功率增加。总的来说，这些发现初步支持领域一般性认知控制机制在双语切换中的参与。
