Department of Psychology, York University, Toronto, Canada; Center for Brain and Cognition (CBC), Universitat Pompeu Fabra, Barcelona, Spain.
Department of Psychology, York University, Toronto, Canada.
Neuropsychologia. 2017 Nov;106:245-260. doi: 10.1016/j.neuropsychologia.2017.09.017. Epub 2017 Sep 21.
The present study investigated processing differences between young adults who were English monolinguals or English-French bilinguals on a task- and language-switching paradigm. The mechanisms responsible for task switching and language switching were investigated using electrophysiological (EEG) measures. In nonverbal task switching, monolinguals and bilinguals demonstrated equivalent behavioral mixing (pure vs. repeat) and switching (repeat vs. switch) costs, but bilinguals were more accurate in the mixed blocks. Bilinguals used a more distributed neural network than monolinguals that captured the nonverbal mixing effect and showed earlier discrimination for the switching effect in the ERPs. In language switching, more distributed networks for bilinguals than monolinguals were found for the switching effect. The scalp distributions revealed more overlap between task switching and language switching for bilinguals than monolinguals. For switch costs, both groups showed P3/LPC modulations in both tasks, but bilinguals showed extended activation to central regions for both switching tasks. For mixing costs, both groups revealed modulations of the N2 but only bilinguals showed extended activation to the occipital region. Overall bilinguals revealed more overlapping processing between task- and language-switching than monolinguals, consistent with the interpretation of integration of verbal and nonverbal control networks during early visual processing for bilinguals and later executive processing for monolinguals.
本研究采用任务和语言转换范式，调查了以英语为母语的年轻人和英法双语者在处理任务时的差异。通过使用脑电图（EEG）测量，研究了负责任务转换和语言转换的机制。在非言语任务转换中，单语者和双语者在混合（纯与重复）和转换（重复与转换）成本上表现出相同的行为表现，但双语者在混合块中更准确。双语者比单语者使用更分散的神经网络，该网络捕捉到了非言语混合效应，并在 ERP 中更早地区分了转换效应。在语言转换中，双语者比单语者在转换效应中表现出更分散的网络。头皮分布显示双语者在任务转换和语言转换之间的重叠比单语者更多。对于转换成本，两组在两个任务中都显示了 P3/LPC 的调制，但双语者在两个转换任务中都显示了对中央区域的扩展激活。对于混合成本，两组都显示了 N2 的调制，但只有双语者显示了对枕叶区域的扩展激活。总的来说，双语者在任务和语言转换之间表现出更多的重叠处理，这与双语者在早期视觉处理中整合言语和非言语控制网络，以及单语者在后期执行处理中的解释一致。
