The Dynamic Role of Subphonemic Cues in Speech Perception: Investigating Coarticulatory Processing Across Sound Classes

Abstract

<p>Neural responses to anticipatory coarticulatory cues were investigated across systematically varying phonological conditions. Congruent or incongruent subphonemic information was placed between an initial consonant and a vowel in a consonant-vowel- consonant (CVC) spoken word (Archibald & Joanisse, 2011). Due to physical and temporal differences across sound classes, the objective was to investigate whether coarticulatory information would be processed differently across controlled manipulations of onset (fricative vs. stop) and vowel type (height vs. backness). Event- related potentials (ERPs) were recorded during a printed-word/spoken-word matching paradigm, in which participants indicated whether a visual prime stimulus and a spoken word matched/mismatched. The “Phonological Mapping Negativity” (PMN) component provides strong evidence that the use of coarticulatory information in speech recognition varies in strength and timing as a function of onset type (fricative vs. stop) and vowel height (high vs. low). Coarticulatory cues were more readily perceived in spoken word beginning with fricatives than with stops. Similarly, subphonemic variations were more easily detected in low vowels than in high vowels. Observed perceptual and temporal differences are interpreted to reflect variations in subphonemic and phonological processing.</p>