Offline consolidation supersedes prior knowledge benefits in children's (but not adults') word learning

Prior linguistic knowledge is proposed to support the acquisition and consolidation of new words. Adults typically have larger vocabularies to support word learning than children, but the developing brain shows enhanced neural processes that are associated with offline memory consolidation. This study investigated contributions of prior knowledge to initial word acquisition and consolidation at different points in development, by teaching children and adults novel words (e.g., ballow) that varied in the number of English word-form “neighbours” (e.g., wallow, bellow). Memory for the novel word-forms was tested immediately after training, the next day, and one week later, to assess the time-course of prior knowledge contributions. Children aged 7-9 years (Experiments 1, 3) and adults (Experiment 2) recalled words with neighbours better than words without neighbours when tested immediately after training. However, a period of offline consolidation improved overall recall and reduced the influence of word-form neighbours on longer-term memory. These offline consolidation benefits were larger in children than adults, supporting theories that children have a greater propensity for consolidating more distinctive language information. Local knowledge of just a single word-form neighbour was enough to enhance learning, and this led to individual differences in word recall that were related to adults’ global vocabulary ability. The results support the proposal that the relative contributions of different learning mechanisms change across the lifespan, and highlight the importance of testing theoretical models of word learning in the context of development.

Link to published article: https://onlinelibrary.wiley.com/doi/10.1111/desc.12776

先前语言知识的提出旨在支持新词汇的习得与巩固。成年人相较于儿童，通常拥有更为丰富的词汇量以支持词汇学习，但发育中的大脑表现出与离线记忆巩固相关的增强神经过程。本研究通过教授儿童和成年人新颖词汇（例如，ballow），这些词汇在英语词形“邻近词”的数量上存在差异（例如，wallow, bellow），探究了先前知识在不同发展阶段对初始词汇习得与巩固的贡献。测试了新颖词形的记忆，分别在训练后立即、次日以及一周后进行，以评估先前知识贡献的时间进程。7-9岁儿童（实验1、3）和成年人（实验2）在训练后立即的测试中，对于具有邻近词的词汇回忆优于不具有邻近词的词汇。然而，一段离线巩固期改善了总体回忆，并减少了词形邻近词对长期记忆的影响。这些离线巩固的益处在儿童中比成年人中更为显著，支持了儿童更有可能巩固更独特语言信息的理论。仅单个词形邻近词的本地知识就足以增强学习，这导致了与成年人全局词汇能力相关的个体差异在词汇回忆上的表现。研究结果支持了不同学习机制相对贡献随生命周期变化的观点，并强调了在发展背景下测试词汇学习理论模型的重要性。