Traditionally, models of speech comprehension and production do not depend on concepts and processes from the phonological short-term memory (pSTM) literature. Likewise, in working memory research, pSTM is considered to be a language-independent system that facilitates language acquisition rather than speech processing per se. We discuss couplings between pSTM, speech perception and speech production, and we propose that pSTM arises from the cycling of information between two phonological buffers, one involved in speech perception and one in speech production. We discuss the specific role of these processes in speech processing, and argue that models of speech perception and production, and our understanding of their neural bases, will benefit from incorporating them.

Languages differ depending on the set of basic sounds they use (the inventory of consonants and vowels) and on the way in which these sounds can be combined to make up words and phrases (phonological grammar). Previous research has shown that our inventory of consonants and vowels affects the way in which our brains decode foreign sounds (Goto, 1971; Näätänen et al., 1997; Kuhl, 2000). Here, we show that phonological grammar has an equally potent effect. We build on previous research, which shows that stimuli that are phonologically ungrammatical are assimilated to the closest grammatical form in the language (Dupoux et al., 1999). In a cross-linguistic design using French and Japanese participants and a fast event-related functional magnetic resonance imaging (fMRI) paradigm, we show that phonological grammar involves the left superior temporal and the left anterior supramarginal gyri, two regions previously associated with the processing of human vocal sounds.