Intrinsic Reward Modulates Word Learning in Both Oral and Written Contexts

Previous studies show that word learning from context can be intrinsically rewarding, even in the absence of external feedback or incentives. Intrinsic reward activates the brain's reward-memory circuit, leading to enhanced memory for words people enjoyed learning. Existing studies have tested the link between contextual word learning and reward in the written domain (i.e., through reading). However, word learning from context often occurs in the oral domain, where conversations provide a rich source for acquiring vocabulary in both first and second language learning. In this online behavioral study, we investigate whether word learning triggers enjoyment across modalities, focusing on listening, reading, and listening and reading in combination. In all the modalities, we found that when words are successfully learned from context, people report greater levels of enjoyment. We also found that words that were associated with higher enjoyment during learning were recognised more accurately than those associated with lower enjoyment 24 hours later. Our results demonstrate the relevance of intrinsic reward for language learning and suggest that the link between contextual word learning and reward operates on higher-level word representations, rather than on modality-specific ones.