Shifting between storage and computation in lexical retrieval: evidence from pronunciation variation
Clara Cohen, Matthew T. Carlson · 2024
Traditional models of lexical retrieval distinguish between whole-word retrieval and computation-based retrieval of inflected word forms. In the former, a word form is stored and retrieved as a complete unit. In the latter, the word form must be created through the combination of individually stored components that make up the target word form’s inflectional paradigm. In this study, we propose a way of understanding these different modes of retrieval through the lens of exemplar theory. To that end, we examine how pronunciation varies as a function of three different probabilistic measures: contextual probability, a property of a word form within a sentence; paradigmatic probability, a property of the word form irrespective of context; and inflectional entropy, a property of the inflectional paradigm. Using the Buckeye corpus of conversational English, we extracted all nouns and verbs and analyzed their duration and vowel centralization in (a) bare stem forms and (b) their s-suffixed forms. The results show that when paradigmatic probability is high, verb stem duration decreases. At the same time, higher inflectional entropy conditions both longer verb stem duration and decreased vowel dispersion. Further, the effects on verb stem duration are strongest when contextual probability within the sentence is highest. In the context of exemplar- theoretic models of lexical storage, we propose that contextual probability and inflectional entropy influence how speakers navigate the stored exemplars of an inflectional paradigm. When contextual and paradigmatic probabilities are high, speakers retrieve exemplars in a way similar to whole-word retrieval, while lower contextual probability and higher inflectional entropy shift the process toward something that resembles computation. Yet, we conclude, our exemplarbased model allows us to understand both types of retrieval as instantiations of the same fundamental process.