Contrasting dynamics of memory consolidation for novel word forms and meanings revealed by behavioral and neurophysiological markers

LAURA KACZER; BAVASSI, LUZ; PETRONI, AGUSTIN; RODRIGO FERNANDEZ; LAURINO, JULIETA; SOFIA DEGIORGI; EITHAN HOCHMAN; CECILIA FORCATO; MARIA EUGENIA PEDREIRA

NEUROPSYCHOLOGIA

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2018

0028-3932

Learning novel words is a challenging processfor our memory systems; we must be able to recall new word forms and meaningsin order to communicate. However, the dynamics of the word memory formation isstill unclear. Here, we addressed the temporal profileof two keycognitive markersof memory consolidation in the domain of word learning:i) the susceptibility of recentlylearned novel words to memory interference; ii)theirlexicalintegration using a semantic judgment task while recording the ERPs responses.Youngadults acquired a set of novel picture-label-meaning associations. In a firstexperiment, we performed atemporal gradient of retroactive interference (5min, 30 min, 4h and 24h) andevaluated the memory retention 48h after learning. In a second experiment, westudied the dynamics of the integration of these novel words, by measuring theirN400 modulationwhen preceded by semantically related words, at 30 min or 48 h after learning. Ourresults showed that the word-formmemory was affected by the interferencetreatment when it was presented 5 min after learning, but not at later times. On the other hand, only 48h after learning it was possibleto observe a neurophysiological index of semantic-priming (reduced N400 response). Theseresults point to the existence of two contrasting processes that help to build the memory forword forms and meanings.A rapid mechanismwould enable word learning while mitigating forgetting, while a slow consolidationwould allow the novel meanings to be integrated into previous semanticnetworks.