AI 中文总结
该研究通过自动语音识别模型模拟国际被收养者经历，发现被遗忘语言的语音痕迹存于模型底层，可加快重新学习速度，表明关键期效应源于基础表征固化而非可塑性丧失。
AI 中文摘要
国际被收养者会保留他们已无法言说或理解的出生语言的语音痕迹，这种持续性通常被归因于生物时间节点的关键期。我们利用自动语音识别模型模拟国际被收养者的经历，且排除成熟度混杂因素，探究这种现象是否可反映普通学习动态。模型在一种语言上训练后，突然切换到第二种语言。我们发现，第一种语言的痕迹在第二语言训练中持续存在，但主要位于最底层的音位前层。这些痕迹具有功能：早期接触过第一种语言的模型重新学习已遗忘的第一种语言的速度比初始模型快14%；即便与从相关语言早期被收养的模型相比，该优势依然存在；当用未被收养模型的最底层替换时，该优势消失。我们认为，这些关键期效应反映的是基础表征的固化，而非可塑性的成熟度丧失，且经验在语言习得关键期中发挥核心作用。
英文摘要
International adoptees retain phonological traces of a birth language they can no longer speak or comprehend, a persistence typically attributed to a biologically-timed critical period. We asked whether it could instead reflect the ordinary dynamics of learning, using automatic speech recognition models that simulate the international adoptee experience without maturational confounds. Models were trained on one language and then abruptly switched to a second. We found that traces of the first language persisted throughout second-language training, but mainly in the lowest, pre-phonemic layers. These traces were functional, as models with early exposure re-learned their lost first language 14% faster than naive models; this advantage held even against models adopted early from a related language and disappeared when the earliest layers were substituted from a non-adopted model. We argue that these critical-period effects reflect entrenchment of foundational representations rather than a maturational loss of plasticity, and that experience plays a central role in critical periods in language acquisition.
