The perception of Korean laryngeal contrasts by native speakers of English: Evidence from an fMRI study

1 Introduction It has long been observed that adult speakers have considerable difficulty recognizing nonnative allophones which correspond to a single phoneme or phonetic category in their own languages (as first reported by Lado 1957, followed up experimentally by Eckman et al. 2003). In support of these findings, event-related brain potential (ERP) studies exhibited different mismatch negativity between native and nonnative, hard-to-perceive categories (Winkler et al. 1999; Sharma and Dorman 2000). Also, recent fMRI (functional Magnetic Resonance Imaging) studies demonstrated a measure of reorganization in the brain regions involving specifically the learning of nonnative Hindi dental-retroflex contrasts (Golestani & Zatorre 2004) and Mandarin lexical tone distinctions (Wang et al. 2003). However, the former revealed that after learning the nonnative sounds, the second-language speakers produced no significant difference in the brain activation regions from the native-language speakers when both groups performed a perception task. Recently, Callan et al. (2004) compared brain activation directly involving perception of the English /r/-/l/ contrast between English native speakers and Japanese native speakers who had learned to perceive the contrast over a period of one month. Unlike the result of Golestani and Zatorre (2004), Callan et al. found a result which seems to support the Internal Model they proposed. The Internal Model is a mechanism that simulates how various mappings between different brain regions are used for identifying difficult second-language phonetic contrasts. The model stipulates that the second language learners, in processing learned sounds that are difficult for them, will use articulatory-auditory mappings more,