Converging evidence for [coronal] underspecification in English-speaking adults

- English phonemes with varying specified distinctive features were contrasted.
- The less specified/dɑ/deviant elicited a large MMN.
- The/dɑ/standard syllable elicited larger responses than did the/bɑ/standard.
- At the single-subject level, all participants had measurable differences between standard syllables.
- Neural evidence supports the notion of [coronal] consonant underspecification in English.

The goal of this study was to test the predictions of the Featurally Underspecified Lexicon (FUL) theory by examining event-related potential (ERP) indices of phonological representation. Two English consonants differing in place of articulation were selected: [labial]/b/and [coronal]/d/. It was assumed that the phonological representation of/d/contained less distinctive feature information due to its [coronal] place of articulation, as compared to/b/. English-speaking adults were presented with two syllables,/bɑ/and/dɑ/, in an ERP oddball paradigm where both syllables served as the standard and deviant stimulus in opposite stimulus sets. Three types of analyses were conducted: traditional mean amplitude measurements, cluster-based permutation tests, and single-trial general linear model (GLM) analyses of group-level and single-subject data. The less specified/dɑ/deviant elicited a large MMN while no MMN was elicited by the more specified deviant/bɑ/. Additionally, the/dɑ/standard syllable elicited larger responses than did the/bɑ/standard, while deviant syllables did not differ. This implies that the MMN was driven by responses elicited by the standards rather than the deviants. At the single-subject level, not all participants demonstrated significant MMN responses, though all had measurable differences between the standard syllables. Thus, to continue to propose that [coronal] underspecification is a language universal phenomenon, ERP indices other than the MMN should be examined.