Prime saliency in semantic priming with 18-month-olds.

This study investigated semantic priming in 18-month-old infants using the inter-modal priming technique, focusing on the effects of prime repetition on saliency. Our findings showed that prime repetition led to longer looking times at target referents for related primes compared to unrelated primes, supporting the existence of a structured semantic system in infants as young as 18 months. The results are consistent with both Spreading Activation and Distributed models of semantic priming. Additionally, our findings highlighted the impact of prime-target stimulus onset asynchronies (SOAs) on priming effects, revealing positive, negative, or no priming effects depending on the chosen SOA. A post-hoc explanation of this finding points to negative priming as a possible mechanism. The study also demonstrated the utility of the inter-modal priming task in studying lexical-semantic structure in younger infants with its diverse measures of infant behaviour.