[Progresses in the understanding of bilingual switching mechanisms based on neuroimaging techniques].

In the field of bilingualism research, a key scientific question is how bilinguals process two language systems, particularly the effective switch from one language to another, namely bilingual code switching. With the rapid development of neuroimaging techniques, important progresses have been made in bilingual processing studies, especially in code switching. However, consensus has not been achieved regarding the mechanisms of bilingual code switching. Bilingual switching studies using neuropsychological and neuroimaging techniques have gained insights into the temporal and spatial features of the language switching process and the neurological mechanism, which provide direct evidence for the generation mechanism of bilingual code switching.

Do Emotional Faces Affect Inhibition of Return? An ERP Study.

Inhibition of Return (IOR) refers to an individual's slowed localization or discrimination performance for targets that appear in previously cued versus uncued location after a relatively long delay after cue (∼300-500 ms). The current study adopted a cue-target paradigm and used behavioral and event-related potential (ERP) measures to investigate whether IOR would be modulated by emotional faces during an emotion recognition task. For reaction time measure, we found IOR effect and the magnitude of IOR effect were comparable for fearful face target and neutral face target. For ERP measures, valid cues were associated with smaller P1 and larger N1 waveform than that for invalid cues. Fearful faces were associated with a larger N170 than neutral faces. The onset latency of the stimulus-locked lateralised readiness potential (LRP) in the valid cue condition was longer than that in the invalid cue condition, while there was no significant difference on the onset latency of the response-locked LRP between the valid cue and invalid cue condition. These results support the notion that, regardless the emotion component of the stimulus, the inhibitory bias of attention to previous visited location before response contributes to the IOR.

Bilingual cognitive control in language switching: an fMRI study of English-Chinese late bilinguals.

The present study explored the bilingual cognitive control mechanism by comparing Chinese-English bilinguals' language switching in a blocked picture naming paradigm against three baseline conditions, namely the control condition (a fixation cross, low-level baseline), single L1 production (Chinese naming, high-level baseline), and single L2 production (English naming, high-level baseline). Different activation patterns were observed for language switching against different baseline conditions. These results indicate that different script bilingual language control involves a fronto-parietal-subcortical network that extends to the precentral gyrus, the Supplementary Motor Area, the Supra Marginal Gyrus, and the fusiform. The different neural correlates identified across different comparisons supported that bilingual language switching involves high-level cognitive processes that are not specific to language processing. Future studies adopting a network approach are crucial in identifying the functional connectivity among regions subserving language control.