Tone language experience enhances dimension-selective attention and subcortical encoding but not cortical entrainment to pitch.

What factors determine the importance placed on different sources of evidence during speech and music perception? Attention-to-dimension theories suggest that, through prolonged exposure to their first language (L1), listeners become biased to attend to acoustic dimensions especially informative in that language. Given that selective attention can modulate cortical tracking of sounds, attention-to-dimension accounts predict that tone language speakers would show greater cortical tracking of pitch in L2 speech, even when it is not task-relevant, as well as an enhanced ability to attend to pitch in both speech and music. Here, we test these hypotheses by examining neural sound encoding, dimension-selective attention, and cue-weighting strategies in 54 native English and 60 Mandarin Chinese speakers. Our results show that Mandarin speakers, compared to native English speakers, are better at attending to pitch and worse at attending to duration in verbal and non-verbal stimuli; moreover, they place more importance on pitch and less on duration during speech and music categorization. The effects of language background were moderated by musical experience, however, with Mandarin-speaking musicians better able to attend to duration and using duration more as a cue to phrase boundary perception. There was no effect of L1 on cortical tracking of acoustic dimensions. Nevertheless, the frequency-following response to stimulus pitch was enhanced in Mandarin speakers, suggesting that speaking a tone language can boost processing of early pitch encoding. These findings suggest that tone language experience does not increase the tendency for pitch to capture attention, regardless of task; instead, tone language speakers may benefit from an enhanced ability to direct attention to pitch when it is task-relevant, without affecting pitch salience.