Perception of prosodic hierarchical boundaries in Mandarin Chinese sentences.

The current study aimed at investigating the processing of prosodic hierarchical boundaries in Mandarin Chinese sentences using electroencephalography, mainly focused on the following questions: (1) whether prosodic boundaries at different levels could evoke the closure positive shift reflecting prosodic boundary perception; (2) what were the differences between them at latency, amplitude and topography; (3) whether this positive component was modified by the variations of acoustic cues (e.g. pause). Main results were: (1) As the previous studies indicated, intonational phrases elicited the closure positive shift as a marker of online speech structuring; (2) phonological phrases evoked the same positive effect with shorter onset latency and somewhat lower amplitude; (3) when the pauses in the vicinity of prosodic boundaries were entirely removed, the original latency difference between the two conditions disappeared, which clearly demonstrated the influence of pause on prosodic boundary processing; (4) prosodic word boundaries only induced amplitude variation waving around the baseline, which was more positive compared with the one elicited by syllable boundaries. The present results indicated that listeners were very sensitive to both intonational phrase boundaries and phonological phrase boundaries.