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

Area of Science:

• Linguistics
• Psycholinguistics
• Cognitive Neuroscience

Background:

• The Featurally Underspecified Lexicon (FUL) theory posits that certain phonological features are underspecified.
• Coronal consonants, like /d/, are hypothesized to have less feature information than labial consonants, like /b/.
• Event-related potentials (ERPs) offer insights into the neural processing of speech sounds.

Purpose of the Study:

• To test FUL theory predictions using ERPs.
• To investigate neural indices of phonological representation for English /b/ and /d/.
• To determine if coronal underspecification influences early neural responses.

Main Methods:

• Utilized an ERP oddball paradigm with English syllables /bɑ/ and /dɑ/.
• Presented syllables as both standard and deviant stimuli.
• Employed mean amplitude, cluster-based permutation tests, and single-trial GLM analyses.

Main Results:

• A significant mismatch negativity (MMN) was observed for the less specified /dɑ/ deviant, but not for the more specified /bɑ/ deviant.
• Standard /dɑ/ elicited larger responses than standard /bɑ/, suggesting MMN was driven by standard processing.
• Individual participant data showed variability in significant MMN responses.

Conclusions:

• The findings challenge the interpretation of MMN as solely reflecting deviant processing in this context.
• Results question the universal application of coronal underspecification based on MMN.
• Further research using alternative ERP measures is recommended to explore phonological representation.