Phonological familiarity facilitates the learning of homophones in adults: Behavioral and ERP evidence

Homophones share identical pronunciations but differ in spelling and meaning, presenting a challenge in language acquisition. This study investigated whether the phonological familiarity of novel homophones aids the learning of orthographic forms and meanings or whether a mismatch between familiar sounds and new orthography creates obstacles to acquisition. Using Russian words, we created pseudohomophones that are identical in pronunciation to familiar words but have different spellings, as well as non-homophonic pseudowords that differ from familiar words in both pronunciation and spelling. Twenty-eight participants learned pseudohomophones and pseudowords in two experiments. We assessed orthographic and semantic acquisition using behavioral tasks and evaluated neural responses before and after learning using ERPs. Pseudohomophones were learned faster and their orthographic forms acquired better than those of pseudowords. Before learning, pseudowords elicited a larger N400 than familiar words, whereas pseudohomophones did not differ significantly, suggesting that phonological similarity hindered their distinction from real words. After learning, pseudowords showed modulations in the P200, N250-P325, and P600 components, reflecting the formation of new orthographic, phonological, and semantic representations. In contrast, only the P600 was modulated for pseudohomophones, likely because their phonology was already familiar. Moreover, comparison between pseudohomophones and pseudowords revealed greater modulation in frontal regions around 300 ms for pseudowords due to the learning session, indicating the formation of phonological representations and increased attentional demands. These findings are compatible with the connectionist dual-process model, suggesting a learning advantage for pseudohomophones based on existing phonological representations.