How auditory rhythm perception shapes speech production: The influence of neural synchronization and rhythmic patterns.

Auditory rhythm perception facilitates language processing, yet it remains unclear how neural synchronization to external rhythms contributes to speech production. The present study examined whether individual differences in neural synchronization modulate rhythmic priming effects during speech production and whether such effects depend on the rhythmic structure of the target utterance. Eighty-six native Mandarin speakers performed a speech production task involving two four-syllable rhythmic patterns as targets: the dominant [2+2] pattern (boundary after the second syllable) and the less common [1+3] pattern (boundary after the first syllable). Each target was preceded by a rhythmically congruent or incongruent pure-tone prime. Neural synchronization to the primes was quantified using cerebral-acoustic coherence (CACoh) between EEG activity and the temporal envelope of the auditory rhythms, and rhythmic priming was assessed using response latencies. K-means clustering of CACoh measures identified two participant groups characterized by relatively high and low levels of neural synchronization. Behavioral analyses revealed a significant Group × Target Type interaction. For the less common [1+3] pattern, low synchronizers exhibited reliable rhythmic priming, whereas high synchronizers showed little or no priming benefit. In contrast, priming effects for the dominant [2+2] pattern were modest and comparable across groups. Furthermore, higher theta-band CACoh was associated with smaller priming effects for [1+3] targets, indicating that stronger neural synchronization predicted reduced behavioral facilitation. These findings suggest that the influence of auditory rhythm on speech production depends jointly on individual neural synchronization capacity and the rhythmic structure of the planned utterance. The results provide new evidence that auditory-motor interactions in speech production are shaped by both listener-specific and utterance-specific factors.