Perceptual and response interactions in semantic priming.

In two experiments, subjects made pairs of lexical decisions verbally. In Experiment 1, masked stimuli appeared concurrently to the left and right of fixation; in Experiment 2, nonmasked stimuli appeared sequentially at fixation. The left-hand letter strings were judged more accurately in in Experiment 1, and the second letter strings were judged more accurately in Experiment 2. Each string in the pair could be either a word (e.g., fork) or a nonword anagram (e.g., frok). Consequently, the two strings in the pair could be related (e.g., fork-spoon, frok-spoon, etc.) or unrelated (e.g., fork-door, frok-door, etc.), independently of whether neither, either, or both strings were words. Semantically related stimuli induced consistent biases to respond "word," as noted in other studies. These biases were typically stronger for the event reported second. Minimal evidence was found for perceptual priming effects. The asymmetrical effects were consistent with spreading-activation-type mechanisms, but other considerations support a multiple-process view.