ERPs show that classroom-instructed late second language learners rely on the same prosodic cues in syntactic parsing as native speakers

The loss of brain plasticity after a 'critical period' in childhood has often been argued to prevent late language learners from using the same neurocognitive mechanisms as native speakers and, therefore, from attaining a high level of second language (L2) proficiency [7], [11]. However, more recent behavioral and electrophysiological research has challenged this 'Critical Period Hypothesis', demonstrating that even late L2 learners can display native-like performance and brain activation patterns [17], especially after longer periods of immersion in an L2 environment. Here we use event-related potentials (ERPs) to show that native-like processing can also be observed in the largely under-researched domain of speech prosody - even when L2 learners are exposed to their second language almost exclusively in a classroom setting. Participants listened to spoken sentences whose prosodic boundaries would either cooperate or conflict with the syntactic structure. Previous work had shown that this paradigm is difficult for elderly native speakers, however, German L2 learners of English showed very similar ERP components for on-line prosodic phrasing as well as for prosody-syntax mismatches (garden path effects) as the control group of native speakers. These data suggest that L2 immersion is not always necessary to master complex L2 speech processing in a native-like way.