Proto-Lexicon Size and Phonotactic Knowledge are Linked in Non-Māori Speaking New Zealand Adults

Most people in New Zealand are exposed to the Māori language on a regular basis, but do not speak it. It has recently been claimed that this exposure leads them to create a large proto-lexicon, consisting of implicit memories of words and word parts, without semantic knowledge. This yields sophisticated phonotactic knowledge (Oh et al., 2020). This claim was supported by two tasks in which Non-Māori-Speaking New Zealanders: (i) Distinguished real words from phonotactically matched non-words, suggesting lexical knowledge; (ii) Gave wellformedness ratings of non-words almost indistinguishable from those of fluent Māori speakers, demonstrating phonotactic knowledge.Oh et al. (2020) ran these tasks on separate participants. While they hypothesised that phonotactic and lexical knowledge derived from the proto-lexicon, they did not establish a direct link between them. We replicate the two tasks, with improved stimuli, on the same set of participants. We find a statistically significant link between the tasks: Participants with a larger proto-lexicon (evidenced by performance in the Word Identification Task) show greater sensitivity to phonotactics in the Wellformedness Rating Task. This extends the previously reported results, increasing the evidence that exposure to a language you do not speak can lead to large-scale implicit knowledge about that language.