Semantic priming and retrieval from lexical memory: Roles of inhibitionless spreading activation and limited-capacity attention

Prior to each target letter string presented visually to 120 university students in a speeded word-nonword classification task, either {bird, body, building,} or {xxx} appeared as a priming event. Five types of word-prime/word-target trials were used: bird-robin, bird-arm, body-door, body-sparrow, and body-heart. The stimulus onset asynchrony (SOA) between prime and target letter string varied between 250 and 2,000 msec. At 2,000-msec SOA, reaction times (RTs) on bird-robin type trials were faster than on xxx-prime trials (facilitation), whereas RTs on bird-arm type trials were slower than on xxx-prime (inhibition). As SOA decreased, the facilitation effect on bird-robin trials remained constant, but the inhibition effect on bird-arm decreased until, at 250-msec SOA, there was no inhibition. For Shift conditions at 2,000-msec SOA, facilitation was obtained on body-door type trials and inhibition was obtained on body-sparrow type. These effects decreased as SOA decreased until there was no facilitation or inhibition. On body-heart type trials, there was an inhibition effect at 2,000 msec SOA, which decreased as SOA decreased until, at 250-msec SOA, it became a facilitation effect. Results support the theory of M. I. Posner and S. R. Snyder (1975) that postulated 2 distinct components of attention: a fast automatic inhibitionless spreading-activation process and a slow limited-capacity conscious-attention mechanism. (27 ref)