Semantic and associative priming in picture naming

We report four picture-naming experiments in which the pictures were preceded by visually presented word primes. The primes could either be semantically related to the picture (e.g., "boat"--TRAIN: co-ordinate pairs) or associatively related (e.g., "nest"--BIRD: associated pairs). Performance under these conditions was always compared to performance under unrelated conditions (e.g., "flower"--CAT). In order to distinguish clearly the first two kinds of prime, we chose our materials so that (a) the words in the co-ordinate pairs were not verbally associated, and (b) the associate pairs were not co-ordinates. Results show that the two related conditions behaved in different ways depending on the stimulus-onset asynchrony (SOA) separating word and picture appearance, but not on how long the primes were presented. When presented with a brief SOA (114 ms, Experiment 1), the co-ordinate primes produced an interference effect, but the associated primes did not differ significantly from the unrelated primes. Conversely, with a longer SOA (234 ms, Experiment 2) the co-ordinate primes produced no effect, whereas a significant facilitation effect was observed for associated primes, independent of the duration of presentation of the primes. This difference is interpreted in the context of current models of speech production as an argument for the existence, at an automatic processing level, of two distinguishable kinds of meaning relatedness.