Contrasting dynamics of memory consolidation for novel word forms and meanings revealed by behavioral and neurophysiological markers
KACZER, LAURA; BAVASSI, LUZ; PETRONI, AGUSTÍN; FERNÁNDEZ, RODRIGO S.; LAURINO, JULIETA; DEGIORGI, SOFÍA; HOCHMAN, EITHAN; FORCATO, CECILIA; PEDREIRA, MARÍA E.
PERGAMON-ELSEVIER SCIENCE LTD
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 lexicalintegration 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 retroactiveinterference (5min, 30min, 4h and 24h) and evaluated the memory retention 48h after learning. In a second experiment, we studied the dynamics of the integration of these novel words, by measuring their N400 modulationwhen preceded by semantically related words, at 30min or 48h after learning. Our results showed that the word-form memory was affected by the interference treatment when it was presented 5min after learning,but not at later times. On the other hand, only 48h 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.