Author's School

Graduate School of Arts & Sciences

Author's Department/Program



English (en)

Date of Award

January 2010

Degree Type


Degree Name

Doctor of Philosophy (PhD)

Chair and Committee

Mitchell Sommers


A central question in research on spoken word recognition is whether spoken words are recognized relationally, in the context of other words in the mental lexicon: McClelland & Elman, 1986; Norris, 1994; Luce & Pisoni, 1998). The current research evaluated metrics for measuring the influence of the mental lexicon on spoken word recognition in auditory-only: A-only), visual-only: V-only) and audiovisual: AV) conditions, and assessed the extent to which lexical properties influence recognition similarly across modality of input. Lexical competition: the extent to which perceptually similar words influence recognition of a stimulus word) was quantified using metrics that are well-established in the literature, as well as a novel statistical method for calculating perceptual confusability, based on the Phi-square statistic. The Phi-square statistic proved an effective measure for assessing lexical competition and explained significant variance in A-only and V-only spoken word identification beyond that accounted for by traditional metrics. Because these values include the influence of all words in the lexicon: rather than only perceptually very similar words), it suggests that even perceptually distant words may receive some activation, and therefore provide competition, during spoken word recognition. Spoken word recognition in A-only, V-only, and AV was sensitive to modality-specific lexical competition and stimulus frequency. These findings extend the scope of activation-competition models of spoken word recognition and suggest that the perceptual and lexical properties underlying spoken word recognition are not unique to the A-only domain.


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