AllData.xlsx

This study investigated how talker variability, training density, and working memory capacity interact to modulate the acquisition of Japanese vowel length contrasts by advanced Mandarin-speaking learners. Twenty native Mandarin speakers who had achieved JLPT N1 proficiency participated in a perceptual training experiment. In this experiment, two variables, namely talker variability (high vs. low) and training density (high vs. low), were manipulated. Pre-training and post-training tests were conducted to evaluate participants’ discrimination accuracy and reaction times. Additionally, working memory capacity was measured using digit span and reading span tests. While accuracy improved significantly post-training across conditions, the patterns of reaction time (RT) uncovered nuanced interactions between the training parameters and working memory. The RT results indicated that individual differences in working memory played a crucial role in modulating the learning efficacy. Learners with high working memory capacity reaped greater benefits from the cognitively challenging high variability/high density condition. In contrast, learners with low working memory capacity thrived under the less challenging, high variability/low density condition that effectively alleviated cognitive overload. These findings contribute significantly to refining theoretical models of second language phonological acquisition. They demonstrate that the quality of input interacts dynamically with cognitive capacity, ultimately determining the process of perceptual restructuring. Even for learners at an advanced proficiency level, it may be imperative to design targeted training programs tailored to individual cognitive profiles to persistent phonological plateaus. The results of this study hold important implications for optimizing phonetic training approaches, especially when catering to learners with diverse cognitive capacities.