Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Argentina; Laboratorio de Neurobiología de la Memoria, CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Departamento de Fisiología y Biología Molecular y Celular, Argentina.
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Argentina; Laboratorio de Neurobiología de la Memoria, CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Departamento de Fisiología y Biología Molecular y Celular, Argentina; Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Neuropsychologia. 2018 Aug;117:472-482. doi: 10.1016/j.neuropsychologia.2018.07.001. Epub 2018 Jul 6.
Learning novel words is a challenging process for our memory systems; we must be able to recall new word forms and meanings in order to communicate. However, the dynamics of the word memory formation is still unclear. Here, we addressed the temporal profile of two key cognitive markers of memory consolidation in the domain of word learning: i) the susceptibility of recently learned novel words to memory interference; ii) their lexical integration using a semantic judgment task while recording the ERPs responses. Young adults acquired a set of novel picture-label-meaning associations. In a first experiment, we performed a temporal gradient of retroactive interference (5 min, 30 min, 4 h and 24 h) and evaluated the memory retention 48 h after learning. In a second experiment, we studied the dynamics of the integration of these novel words, by measuring their N400 modulation when preceded by semantically related words, at 30 min or 48 h after learning. Our results showed that the word-form memory was affected by the interference treatment when it was presented 5 min after learning, but not at later times. On the other hand, only 48 h after learning it was possible to observe a neurophysiological index of semantic-priming (reduced N400 response). These results point to the existence of two contrasting processes that help to build the memory for word forms and meanings. A rapid mechanism would enable word learning while mitigating forgetting, while a slow consolidation would allow the novel meanings to be integrated into previous semantic networks.
学习新单词对我们的记忆系统来说是一个具有挑战性的过程；我们必须能够回忆起新单词的形式和含义，以便进行交流。然而，单词记忆形成的动态过程尚不清楚。在这里，我们研究了单词学习领域中记忆巩固的两个关键认知标记的时间进程：i）新近学习的新单词对记忆干扰的敏感性；ii）使用语义判断任务进行词汇整合，同时记录 ERP 反应。年轻成年人学习了一组新的图片-标签-含义关联。在第一个实验中，我们进行了逆行性干扰的时间梯度（5 分钟、30 分钟、4 小时和 24 小时），并在学习后 48 小时评估记忆保留情况。在第二个实验中，我们通过测量学习后 30 分钟或 48 小时这些新单词前面的语义相关词的 N400 调制，研究了这些新单词的整合动态。我们的结果表明，当干扰处理在学习后 5 分钟呈现时，单词形式记忆会受到影响，但在以后的时间不会受到影响。另一方面，只有在学习后 48 小时才能观察到语义启动的神经生理指标（减少的 N400 反应）。这些结果表明存在两种相反的过程，有助于建立单词形式和含义的记忆。一个快速的机制将能够进行单词学习，同时减轻遗忘，而一个缓慢的巩固将允许新的含义整合到以前的语义网络中。
