Role of set in visual word recognition: Activation and activation blocking as nonautomatic processes

The semantic priming effect in lexical decision is widely assumed to reflect automatic processes when the prime is merely read. In contrast, semantic priming is typically eliminated when the prime is subjected to a letter search. The present experiments demonstrate that semantic priming (a) occurs following letter search given a short stimulus onset asynchrony between prime and probe and (b) is reinstated in the standard, simultaneous letter search condition when such trials are mixed with delayed probe trials. These results are discussed in terms of the role of set in the context of an interactive activation framework. Activation and activation blocking are seen as nonautomatic processes controlled by set so as to balance bottom-up and top-down influences.