Listening Fast and Slow: The Role of Declarative and Procedural Memory in Learning Through L2 Aural Input

For many people, learning a second language as an adult is a challenging endeavor. Much interest in the study of adult second language learning has concerned the type of input that learners receive in their second language, with findings suggesting that second language learners are often exposed to a register of speech called ‘foreigner talk’ that is slower, more clearly articulated, and grammatically simpler than speech to fluent speakers. In this dissertation, I focus on rate of speech, which has been independently predicted by a neurocognitive model of second language learning to modulate how a second language is learned. Specifically, drawing on recent theoretical work in second language learning, I predicted that slower speech characteristic of foreigner talk should engage a type of learning and memory called declarative memory, whereas faster speech characteristic of nativelike speech should engage the procedural memory system. To test these predictions, I exposed participants to a relatively brief artificial language learning task and measured their declarative and procedural memory. Results suggested that speech resembling foreigner talk engaged the declarative memory system as predicted, specifically a type of declarative memory involving conscious awareness of patterns in the artificial language. In contrast, I did not find evidence of a role for procedural memory in faster speech resembling nativelike conversation. This work constitutes, to my knowledge, the first examination of how neurocognitive memory systems may support learning from speech resembling foreigner talk. In time, these findings, together with future investigations, may warrant evidence-based recommendations for how teachers should speak to adult learners of second languages in order to best serve their language learning goals.