Neuroimaging of phonetic perception in bilinguals

This review addresses the cortical basis of phonetic processing in bilinguals and of phonetic learning, with a focus on functional magnetic resonance imaging studies of phonetic perception. Although results vary across studies depending on stimulus characteristics, task demands, and participants’ previous experience with the non-native/second-language sounds, taken together, the literature reveals involvement of overlapping brain regions during phonetic processing in the first and second language of bilinguals, with special involvement of regions of the dorsal audio-motor interface including frontal and posterior cortices during the processing of new, or ‘difficult’ speech sounds. These findings converge with the brain imaging literature on language processing in bilinguals more generally, during semantic and syntactic processing of words and of connected speech. More brain imaging work can serve to better elucidate the precise mechanisms underlying phonetic encoding and its interaction with articulatory processes, in particular where multiple phonetic repertoires have been or are being acquired.