An articulatory basis for the labial-to-coronal effect: /pata/ seems a more stable articulatory pattern than /tapa/

This paper investigates the coordination between the jaw, the tongue tip, and the lower lip during repetition with rate increase of labial-to-coronal (L(a)C(o)) consonant-vowel-consonant-vowel disyllables (e.g., /pata/) and coronal-to-labial (C(o)L(a)) ones (e.g., /tapa/) by French speakers. For the two types of disyllables: (1) the speeding process induces a shift from two jaw cycles per disyllable to a single cycle; (2) this shift modifies the coordination between the jaw and the constrictors, and (3) comes with a progression toward either a L(a)C(o) attractor [e.g., (/pata/ or /tapa/) --> /patá/ --> /ptá/] or a C(o)L(a) one (e.g., /pata/ or /tapa/ --> /tapá/ --> /tpá/). Yet, (4) the L(a)C(o) attractor is clearly favored regardless of the initial sequencing. These results are interpreted as evidence that a L(a)C(o) CVCV disyllable could be a more stable coordinative pattern for the lip-tongue-jaw motor system than a C(o)L(a) one. They are discussed in relation with the so-called LC effect that is the preference for L(a)C(o) associations rather than C(o)L(a) ones in CV.CV disyllables in both world languages and infants' first words.