Prosody, syntax and the lexicon in parsing ambiguous sentences
This thesis tests the early incorporation of prosodic information during on-line processing of ambiguous word pairs such as Packing cases. The word pair is syntactically ambiguous between a noun or verb phrase interpretation. However, the two interpretations are prosodically distinct. An on-line, cross-modal, response-time task found that subjects disambiguated the word pairs using prosodic information. Experiment 2 swapped the timing,fo and amplitude of the noun phrase versions with the verb phrase versions. If prosodic information were guiding parsing, swapping the prosody of the alternatives should change subjects' parses of the word-pairs. Subjects interpreted the cross-synthesised noun phrases as verb phrases and the crosssynthesised verb phrases as noun phrases. This provides additional evidence in favour of early prosodic processing. Experiment 3 tested whether subjects' ability to differentiate the two forms would be affected by flattening the fo of the word pairs. Subjects' ability to disambiguate the word pairs was reduced by flattening the fo of the stimuli. Again, this provides evidence in favour of fo guiding parsing. Experiment 4 investigated the perceptual salience of prosodic information in the absence of lexical information, by testing parsing of delexicalised versions of the same wordpairs. Subjects continued to disambiguate the stimuli. This indicates that prosody can guide parsing even without lexical information. The results of the four experiments provide strong evidence in favour of the early incorporation of prosodic information in parsing: prosodic information can influence on-line parsing even in the presence of contradictory syntactic and spectral preferences; and in the absence of lexical information. This thesis concludes that the results of the experiments support strong interaction models of processing.