Neural mechanisms of language learning from social contexts

Humans learn languages in real-life situations by integrating multiple signals, including linguistic forms, their meanings, and the actions and intentions of speakers. However, little is known about the neural bases underlying the social learning of a second language (L2) in adults. In this study, 36 adults were asked to learn two sets of L2 spoken words through translation versus simulated social interactive videos (social learning). Brain activation during word learning was measured using fMRI. Greater activation was observed in the bilateral superior temporal sulcus, posterior middle temporal gyri, and right inferior parietal lobule during social learning as compared with translation learning. Furthermore, higher activity in the right temporal parietal junction, right hippocampus, and motor areas was observed during the initial stage of social learning, with the more successful performance being at the time of overnight testing. We argue that social learning may strengthen the link from new L2 forms to rich L2 semantic representations wherein memory properties are embodied, multimodal, and richly contextualized.