Across two experiments, we examine the relationship between individual differences in working memory (WM) and the acquisition of non-native speech categories in adulthood. While WM is associated with individual differences in a variety of learning tasks, successful acquisition of speech categories is argued to be contingent on WM-independent procedural-learning mechanisms. Thus, the role of WM in speech category learning is unclear. In Experiment 1, we show that individuals with higher WM acquire non-native speech categories faster and to a greater extent than those with lower WM. In Experiment 2, we replicate these results and show that individuals with higher WM use more optimal, procedural-based learning strategies and demonstrate more distinct speech-evoked pupillary responses for correct relative to incorrect trials. We propose that higher WM may allow for greater stimulus-related attention, resulting in more robust representations and optimal learning strategies. We discuss implications for neurobiological models of speech category learning.

在两个实验中，我们检查了工作记忆 (WM) 的个体差异与成年期非母语语音类别的获得之间的关系。虽然 WM 与各种学习任务中的个体差异有关，但成功获得语音类别被认为取决于 WM 独立的程序学习机制。因此，WM 在语音类别学习中的作用尚不清楚。在实验 1 中，我们表明 WM 较高的个体比 WM 较低的个体更快、更大程度地获得非母语语音类别。在实验 2 中，我们复制了这些结果，并表明 WM 较高的个体使用更优化的、基于程序的学习策略，并展示了更明显的语音诱发瞳孔反应，以获得正确的相对于不正确的试验。我们建议更高的 WM 可能允许更大的刺激相关注意力，从而产生更强大的表征和最佳学习策略。我们讨论了对语音类别学习的神经生物学模型的影响。