Beyond spreading activation: an influence of relatedness proportion on masked semantic priming

Semantic priming in the lexical decision task has been shown to increase when the proportion of related-prime trials is increased. This finding typically is taken as evidence for a conscious, strategic use of primes. Three experiments are reported in which masked semantic primes displayed for only 45 msec were tested in high- versus low-relatedness proportion conditions. Relatedness proportion was increased either by using a high proportion of semantically related primes or a large set of repetition-primed filler trials. Semantic priming was consistently enhanced relative to a low-relatedness proportion condition. These relatedness proportion effects were not due to conscious, strategic use of primes: Exclusion of prime-aware subjects did not attenuate the effects, and better performance in a prime classification task was not associated with larger semantic priming effects. These results are interpreted within a retrospective account of semantic priming in which recruitment of a prime event is modulated by prime validity.