Electrophysiological correlates of prosodic boundaries at different levels in Brazilian Portuguese

Abstract

In tasks involving spoken language comprehension, prosodic cues serve as a guide to adequate linguistic processing. In a statement, for instance, a clear-cut set of prosodic cues (i.e., pre-final syllable lengthening, pitch range, pause) is used to segment and organize speech into prosodic constituents, namely intonational phrases (IP) and phonological utterances (U). Though these two highest prosodic constituents are delimited by this same set of acoustic cues, their respective boundaries coincide with different syntactic boundaries. No study has compared neural responses to these cues at boundaries of these two distinct prosodic constituents so far. The present thesis investigated phonetic differences between boundaries associated with these constituents and aimed to provide evidence of detection of these differences by way of an experiment examining an ERP component known as Closure- Positive-Shifts (CPS) evoked in response to processing of acoustic cues signaling prosodic boundaries. The results revealed phonetic strength differences between IP and U boundaries as reflected in acoustic parameters. The preliminary analysis of the behavioral experiment revealed an ERP component elicited in response to processing of these boundaries. These results suggest that, in speech comprehension, listeners are sensitive to prosodic cues associated with syntactic information of different levels.