Bilinguals have different hemispheric lateralization in visual word processing from monolinguals

Abstract

Previous studies showed reduced hemispheric asymmetry (HA) in visual tasks like face perception in bilinguals compared with monolinguals, suggesting experience in reading one or two languages could be a modulating factor. We examined whether HA differences in visual tasks can also be observed in bilinguals with different language backgrounds. We compared the behavior of three groups in a tachistoscopic English word sequential matching task: English monolinguals (alphabetic monolinguals, A-Ms), bilinguals with an alphabetic-L1 and English-L2 (alphabetic-alphabetic bilinguals, AA-Bs), and bilinguals with Chinese-L1 and English-L2 (logographic-alphabetic bilinguals, LA-Bs). The results showed AA-Bs had a stronger left hemispheric lateralization than A-Ms and LA-Bs, suggesting different language learning experiences can influence visual words processing. Our computational model could explain this effect, based on a perceptual HA theory; the modeling data suggested this difference may be due to the differences in both participants’ vocabulary size and word-to-sound mapping between alphabetic and logographic languages.