The facilitatory role of rhyme during implicit and explicit word learning

Purpose: Rhyme increases the phonological similarity of phrases individuals hear and enhances recall from working memory. The present study explores whether rhyme aids word learning and examines the underlying neural mechanisms through which rhyme facilitates word learning. Method: Fifty-seven adults completed a word learning task where they were exposed to 15 nonwords (NWs), four times each, in the sentence-final position as their EEG was recorded. Participants were randomly assigned to either a Rhyme or No-Rhyme group, where the NWs rhymed or did not rhyme with a prime real word in the sentence, respectively, during the exposure phase. Subjects were then tested on their recognition of the NWs. Results: Behavioral accuracy on the NW recognition task did not differ between the Rhyme and No Rhyme groups; however, the Rhyme group showed an enhanced bilateral P2 in the early exposure phase, which has been linked to increased attention to the phonological and semantic features of speech. By contrast, the No-Rhyme group showed an attenuated N400 amplitude at left centro-parietal sites in the later exposure phase, related to semantic retrieval of NWs. Conclusions: These findings indicate that rhyme may facilitate encoding of word meaning via attention to both phonology and semantic information; however, the absence of rhyme does not hinder adults’ ability to map meaning to novel words.