Neural coupling of native/non-native phonetic imitation in children and adults

Abstract

Second language learning is becoming more and more common nowadays, many people are non-native speakers with accents. Many previous studies have found that children perform better than adults in imitating foreign language speech, but the cognitive neural mechanisms need to be further explored, although some studies show that it is still possible to pronounce at a near native level even acquiring second language as an adult. This study focuses on the neurological mechanism of primary school students in listening and speaking English and Chinese syllables, and aims to explore patterns and characteristics of children when processing non-native languages from the perspective of cognitive and neurological function. Using functional nearinfrared spectroscopy (fNIRS) to observe neural activations during listening and speaking speech and behavioural tests to measure children’s verbal cognition. Our results show that there is significant difference between adults and children in the inter-brain synchrony of the native speaker and the corresponding participant when the native speaker is speaking while the participant is also speaking. Results of main effect of language revealed that participants had higher coherence value in their native language, Chinese, than English. Children had higher coherence with the native speakers than the adults in 8 cluster combinations, which are speaker’s left primary somatosensory cortex (PSC) and participant’s right triangular part of inferior frontal gyrus (IFG-tri); speaker’s left superior temporal gyrus (STG) and participant’s left premotor cortex; speaker’s middle temporal gyrus (MTG) and participant’s opercular part of the left inferior frontal gyrus (IFG-oper); speaker’s IFG-tri and participant’s left primary motor cortex (PMC); speaker’s IFG-tri and participant’s right supramarginal gyrus (SMG); speaker’s right superior temporal gyrus (STG) and participant’s left premotor cortex; speaker’s STG and participant’s PMC; speaker’s STG and participant’s left SMG; speaker’s STG and participant’s right SMG. In the Listen-Listen condition, the coherence values is also significant the neural coupling between the native speaker, who is listening to another one’s spoken sound recording, and the participant, who is also listening to the same sounds, the significant cluster combinations were mainly centred over the left primary somatosensory cortex (PSC), the left MTG and the right IFG-tri for the participants. Adults and children had the differential neural responses to English and Chinese tasks.