Neural correlates of second language acquisition of tone-grammar associations

Native speakers of Swedish use tones on stems to predict which suffix is to follow. This is seen behaviorally in reduced response times for matching tone-suffix pairs. Neurophysiologically, online prediction is reflected in the event-related potential (ERP) component pre-activation negativity (PrAN) occurring for tones with a higher predictive value. Invalid suffixes relative to the tone produce a left anterior negativity (LAN), or a broadly distributed negativity, and a P600. When native speakers make decisions about the inflection of words, response times are also longer for invalid tone-suffix combinations. In this study, low to intermediate level second language learners with non-tonal native languages trained tone-suffix associations for two weeks. Before and after training, they participated in a perception test where they listened to nouns with valid and invalid tone-suffix combinations and performed a singular/plural judgment task. During the test, electroencephalography (EEG) and response times were measured. After training, the PrAN effect increased, and a LAN emerged for invalid stimuli, indicating that the participants had acquired the tone-suffix association, using the tones as predictors more extensively post-training. However, neither a P600 nor longer response times for invalidity were found, suggesting potential differences in native and second language processing of the tone-suffix association