Development of bidirectional phono-semantic activation in toddlers

A mediated priming effect refers to the activation of a target via a mediator previously activated by a prime. This effect has been found at 24months of age for phono-semantic links: a prime (cup) activates a target (dog) via a mediator (cat), providing evidence of activation in a forward direction (phonological to semantic). Interactive models, however, propose that activation propagates in both forward and backward directions between processing levels. This study investigated the development of bidirectional co-activation of phonological and semantic levels of processing in Spanish-speaking toddlers. In a primed preferential looking task, participants were exposed to an unlabelled prime image, followed by the presentation of two images, a target and a distractor. In Experiment 1, when images with a semantic-phonological relationship were presented, both 24- and 30-month-olds preferred to look at the named target with a relationship to the prime image (dog-cat-cup). However, when an unrelated target image was named, 24-month-olds preferred to look at the target, but 30-month-olds did not. In Experiment 2, both 24- and 30-month-olds preferred to look at a target with a phono-semantic relationship to the prime (cup-cat-dog) over an unrelated target. These results provide strong evidence of differences in the development of forward and backward interactions between semantic and phonological processing levels.