Alpha synchronisation of acoustic responses in active listening is indicative of native language listening experience

Objective
Examine the effect of language experience on auditory evoked and oscillatory brain responses to lexical tone in passive (ACC) and active (P300) listening conditions.

Design
Language experience was evaluated using two groups, Mandarin- vs. English-listeners (with vs. without lexical tone experience). Two Mandarin lexical tones with pitch movement (T2 rising; T3 dipping) produced on the syllable /ba/ were used as stimuli. For passive listening, each tone was presented in a block. For active listening, each tone was the standard (80%) or deviant (20%) presented in two blocks. Presentation order was counterbalanced across participants in both tasks.

Study sample
10 adult Mandarin-listeners and 13 Australian-English-listeners contributed to the data.

Results
Both global field power (GFP) and time frequency analysis (TFA) failed to detect group differences in passive listening conditions for the ACC response. In contrast, the active listening condition revealed significant group differences for T2. GFP showed a trending significance with larger GFP (less consistent responses) in English- than Mandarin-listeners. TFA showed significantly higher alpha synchronisation (more focussed attention) for Mandarin- compared to English-listeners.

Conclusions
Acoustic responses to speech is influenced by language experience but only during active listening, suggesting that focussed attention is linked to higher level language processes.