Prosody, Performance, and Cognitive Skill: Evidence from Individual Differences

Abstract

If a pause occurs in the middle of a sentence, is it attributable to prosodic structure, planning problems, or both? And if both prosodic representation and performance constraints conspire to cause a speaker to divide a sentence into two units, can the durational effects that result be parsed into those two different sources? In this chapter, we argue that prosody and performance are theoretically and empirically distinct, and that durational effects may arise from two distinct sources: from the implementation of a grammatical representation, and from performance limitations. A range of empirical evidence is presented to support this distinction. Studies investigating the effects of working memory, inhibitory control, and lexical difficulty indicate that individuals with less cognitive capacity are more likely to produce sentence-internal breaks, and these are not conditioned by characteristics of a prosodic representation. This finding suggests that performance units are not necessarily prosodic units, and that an adequate theory of sentence production must incorporate mechanisms for implementing prosodic structure as well as strategies for managing processing load during speech.