Similarity of referents influences the learning of phonological word forms: Evidence from concurrent word learning

Although it is well accepted that various components of words (e.g., phonological word forms, and semantics) interact with each other during processing, it is less clear whether semantics and phonology interact with each other during word learning in the sense of affecting each other's learning. This study employed three behavioral experiments as well as computational simulations to shed light on this issue by examining whether semantic similarity, operationalized as visual referent similarity, influences the learning of phonological word forms. Experiment 1 demonstrated an effect that would typically be interpreted as an effect of similarity on phonological learning, employing the commonly used naming task. We discuss how such results are confounded by at-test competition effects that can arise directly from the explicit presentation of similar referents, or indirectly from their re-activation even without explicit presentation. Experiments 2 and 3 used a stem completion test and a recognition from mispronunciation test to control for direct effects of competition, and still found effects of similarity on performance. A neural network model of word learning simulated the behavioral results, with analysis of the model confirming a genuine effect of referent similarity on phonological learning even when controlling for both direct and indirect at-test similarity effects. Together these results provide converging evidence that phonological word form learning is affected by referent similarity, suggesting that semantics and phonology interact with each other during learning.