Alpha and beta desynchronization during consolidation of newly learned words

While a growing body of literature exists on initial word-to-meaning mapping and retrieval of fully lexicalized words, our understanding on the learning of semantic knowledge that occurs between these two stages remains limited. The current study investigated the neural correlates of retrieving newly learned word meanings using oscillatory brain dynamics. Participants learned to associate new words with unknown objects and performed overt and covert naming tasks during the first and last days of a five-day training period. Behavioral results showed improved overt naming on Day 5 compared to Day 1. Selecting only words that were successfully produced in the overt naming task, we examined alpha (8-12 Hz) and beta (13-25 Hz) band oscillatory activity associated with lexical-semantic retrieval while participants produced new words covertly, both pre-(Day 1) and post (Day 5) lexicalization. The results showed a robust alpha and lower beta power decrease during covert naming after learning. We hypothesize that this alpha-beta power decrease indexes successful word retrieval following lexical-semantic integration and consolidation.