Biomedical subjects

James F Melhorn

Publications and source records attributed to James F Melhorn.

3 recordsLinked to original sources

PubMed2005

Integration of multiple speech segmentation cues: a hierarchical framework.

A central question in psycholinguistic research is how listeners isolate words from connected speech despite the paucity of clear word-boundary cues in the signal. A large body of empirical evidence indicates that word segmentation is promoted by both lexical (knowledge-derived) and sublexical (signal-derived) cues. However, an account of how these cues operate in combination or in conflict is lacking. The present study fills this gap by assessing speech segmentation when cues are systematically pitted against each other. The results demonstrate that listeners do not assign the same power to all segmentation cues; rather, cues are hierarchically integrated, with descending weights allocated to lexical, segmental, and prosodic cues. Lower level cues drive segmentation when the interpretive conditions are altered by a lack of contextual and lexical information or by white noise. Taken together, the results call for an integrated, hierarchical, and signal-contingent approach to speech segmentation.

Cues↗

PubMed2005

Detecting silent pauses in speech: a new tool for measuring on-line lexical and semantic processing.

In this study, we introduce pause detection (PD) as a new tool for studying the on-line integration of lexical and semantic information during speech comprehension. When listeners were asked to detect 200-ms pauses inserted into the last words of spoken sentences, their detection latencies were influenced by the lexical-semantic information provided by the sentences. Listeners took longer to detect a pause when it was inserted within a word that had multiple potential endings, rather than a unique ending, in the context of the sentence. An event-related potential (ERP) variant of the PD procedure revealed brain correlates of pauses as early as 101 to 125 ms following pause onset and patterns of lexical-semantic integration that mirrored those obtained with PD within 160 ms of pause onset. Thus, both the behavioral and the electrophysiological responses to pauses suggest that lexical and semantic processes are highly interactive and that their integration occurs rapidly during speech comprehension.

Humans↗

PubMed2005

How do syllables contribute to the perception of spoken English? insight from the migration paradigm.

The involvement of syllables in the perception of spoken English has traditionally been regarded as minimal because of ambiguous syllable boundaries and overriding rhythmic segmentation cues. The present experiments test the perceptual separability of syllables and vowels in spoken English using the migration paradigm. Experiments 1 and 2 show that syllables migrate considerably more than full and reduced vowels, and this effect is not influenced by the lexicality of the stimuli, their stress pattern, or the syllables' position relative to the edge of the stimuli. Experiment 3 confirms the predominance of syllable migration against a pseudosyllable baseline, and provides some evidence that syllable migration depends on whether syllable boundaries are clear or ambiguous. Consistent with this hypothesis, Experiment 4 demonstrates that CVC syllables migrate more in stimuli with a clear CVC-initial structure than in ambisyllabic stimuli. Together, the data suggest that syllables have a greater contribution to the perception of spoken English than previously assumed.

Analysis of Variance↗