Young children's use of prosodic cues in sentence processing

Youngon Choi & Reiko Mazuka
Duke University

yoc@duke.edu

The present study investigated how young Korean-learning children use prosodic cues in parsing ambiguous sentences.  We consider two types of ambiguities that can be resolved by using a prosodic structure, called Accentual Phrase (AP: Jun, 1993).  Both types of ambiguity derive from variable AP demarcation including prosodic and segmental cues.  First is a segmentation ambiguity where placement of the AP boundary leads to different interpretations of a sentence.  Second is a syntactic ambiguity where an AP boundary is required to resolve the attachment ambiguity of an NP (see examples below).  We also tested whether children had a command of a phonological rule that operates in the domain of AP --- lenis stops such as /p/ and /k/ are voiceless at AP initial position, while they become voiced elsewhere.

We tested 3-4 year-old children in two experiments.  Experiment 1 examined whether children could use AP structures to segment utterances and derive the meaning of potentially ambiguous sentences. Children were asked to imitate pre-recorded sentences and to match them with pictures.  In the Normal condition, sentences were presented with regular prosodic cues and proper voicing for stop consonants. In the Conflict condition, the segmental cues conflicted with the AP boundaries delimited by prosodic cues (i.e., voiced stops at the AP initial positions & voiceless stops intervocalically).  In the Segment-Only condition, prosodic cues were removed so that only segmental cues were available in finding AP boundaries.

When prosodic and segmental cues converged, children were 83% correct in determining the meaning. When these cues conflicted, children were accurate significantly better than chance (59%), but lower than the Normal condition, showing that the conflicting segmental cues disturbed children's parsing decisions.  In the Segment-Only condition, children were 62% correct, indicating that they were able to use the segmental cues when necessary.  This pattern of results closely matched those of Korean adults.

Experiment 2 tested whether children use prosodic information to resolve the syntactic ambiguity using the same methods as in Exp.1.  As shown in Example 2 below, depending upon AP boundaries, the sentence could be interpreted as a Subject-Object-Predicate or Null Subject-Object-Predicate structure.  Unlike adults, children did not appear capable of using prosodic cues properly to disambiguate the meanings.

In sum, children could use the AP boundary to segment a sentence, while they are unable to use the AP boundary to resolve attachment ambiguity.  The results will be discussed in relation to the other studies reporting similar results.

Examples

Experiment 1

Experiment 2

Reference

Jun, S-A. (1993). The Phonetics and Phonology of Korean Prosody. Dissertation, The Ohio State University.