Word-internal segmental repetitions in lexical learning

My project aims to answer some fundamental questions on word learning. What makes a lexicon (the set of words in language) easier to learn? How does learning whole lexicons relate to learning individual words? How is lexical learning affected by the repetition of similar/identical sounds within words?

My interest in these questions stems from a discrepancy revealed in recent studies between how word-internal repetition works in natural languages and what humans find easier to learn in experimental settings. Although word-internal consonant similarities are generally avoided by the languages of the world, in lab experiments words with repeated consonants are better learned than those with no repetitions. By contrast, it is cross-linguistically common for vowels within words to be similar, but repeated vowels do not confer a word learning advantage in the lab. Why would natural languages end up with repetition patterns that make words harder to learn?

While previous research has typically focused on the effect of sound repetitions on individual word learning, I propose to investigate what happens when whole lexicons are considered. I hypothesise that words sharing similar consonants are more easily confused with each other than those sharing similar vowels. This would make lexicons with word-internal consonant repetitions/similarities harder to learn and contribute to explain the paradoxical mismatch between natural language design and word learning advantage. To test this idea and identify potential differences in the perception, memory storage, and processing of consonant- and vowel-matched words, I will carry out similarity judgement, recognition, and recall tasks using auditory stimuli from artificial lexicons.