Do contrastive accents modulate the effect of intonational phrase boundaries in parsing?

Two experiments examined the effect of intonational phrase boundaries (Experiment 1) and interactions between intonational phrase boundaries and contrastive accents (Experiment 2) in parsing, using a sentence continuation judgment task. Across experiments, we found that intonational phrase boundaries were consistently interpreted as signaling syntactic structure as long as there were no alternative reasons for them to be present. Experiment 2 showed that different prosodic cues interact in syntactic processing. The effect of intonational phrase boundaries was modulated by contrastive accents through weaker intermediate phrase boundaries that followed contrastive accents, suggesting that the effects of pitch accents are indirect in syntactic processing.