Scanning the bilingual brain Guillaume Thierry Group 1 Group1 collaborators: Marilyn Vihman, Yan Jing Wu, Jan-Rouke Kuipers, Benjamin Dering

Overview Two streams, Two methods, One paradigm Child Event-Related Potentials Adult Behavioural Measures P P Priming Measure of ERP amplitude, key indices the P300 and N400 waves Measure of head turns or reaction times and error rates

1- Developmental bilingualism Mapping concepts onto words cat dog phone cat dog phone cat picture word Time (ms) picture Match Item mismatch Category match Mismatch dog phone Semantic networking at 16 months English monolinguals Semantic networking at 14 months? Differences between Welsh-English bilingual and monolingual children?

1- Developmental bilingualism Input code-switching in 2 – 4 year olds Do 2 – 4 year olds detect code changes? Does code-switching affect semantic processing in 2 – 4 year olds? In adults, the oddball paradigm elicits a ‘P300’ peak which indexes working memory updating / attention shifting Semantic priming can be tested within and between languages using the ‘N400’ index

2 – Adult bilingualism Unconscious access to the native language Thierry and Wu, Proc. Nat. Acad. Sci. USA, 2007 Semantic Relatedness RelatedUnrelated Repeated Character Repetition The effect of Chinese character repetition in bilinguals reading only English words demonstrates unconscious translation Not repeated Phonology or orthography? Is this effect found when both languages are based on the roman alphabet (e.g., French and English)? What is the impact of word concreteness / imageability?

2 - Adult bilingualism Automatic semantic access in bilinguals Ignore English words and count letters in Welsh words sebonagoriadrhyfelcoedenjudgechairdeilensoaphosanwarleaftreebubbleeirallygreddffatritreeleafcoeden deilen – coeden deilen – sebon deilen – tree deilen – soap leaf – coeden leaf – sebon leaf – tree leaf – soap Prime EnglishWelsh English Welsh Target Comparing neural adaptation in brain regions activated by reading Is semantic access automatic in the ‘deactivated’ language?

Diolch! Thank you! Guillaume Thierry Group 1