BOUCHON, C. & TORO, J. M.
Language and Comparative Cognition Group, Center for Brain and Cognition, University Pompeu Fabra, Barcelona, Spain
The Consonant bias, evidenced by a greater reliance on consonants over vowels in lexical tasks (Nespor et al, 2003), shows the ability to assign specific functions to different speech-sounds. In adulthood this is attested in written and oral modalities, many tasks and languages (Cutler et al. 2000). Moreover, different cortical networks underlie consonant and vowel lexical processing (Sharp et al., 2005). Studies with French and Italian infants show they switch from an acoustically-driven reliance on vowels for word identification at 5 months (Bouchon et al., 2014) to a consonant bias at 8 months (Nishibayashi & Nazzi, 2016; Hochmann et al., 2011), suggesting that it could play an essential role in their early quest for words. In the present set of experiments we tackled two questions: which factors favor an early emergence of this bias? Is it a human-specific mechanism or could non-human animals exhibit it? Study 1 demonstrates that Spanish infants switch from a vowel to a consonant bias between 5 and 12 months of age. Study 2 shows that non-human animals (in this case, rats) rely more heavily on vowels to identify word-forms. Together these experiments suggest that the consonant bias emerges from human-specific mechanisms of language processing.