On idle idols and ugly icons: Investigating lexical selection in typing through homophones

Homophone errors (e.g., there/their) are not uncommon in typing, but it is debated whether they simply reveal poor spelling knowledge or signal competition in the production system. We tested the idea that competition underlies the greater difficulty associated with producing homophone, compared to non-homophone, targets. Using computational simulations, we showed that competition alone is sufficient to produce interference during homophone production, and that such interference is exacerbated by increasing lexical competition. These predictions were confirmed in two experiments, a typing-to-dictation task (Experiment 1) and a question-answering task (Experiment 2). We further showed the homophone effect was insensitive to the syntactic category: we found a robust homophone interference effect of a comparable magnitude for same-category (e.g., flower-flour) and different-category (e.g., idol-idle) homophones. Collectively, these results show that lexical selection in typing is similar to speaking in terms of the processes arising from representational overlap, but distinct from it in terms of the influence of syntax.