Masked orthographic priming: The effect of prime-target legibility

The occurrence of extensive orthographic form-priming may provide reasons for preferring connectionist-type models over table-lookup (algorithmic) ones. Short-term masked priming procedures, using either tachistoscopic identification or lexical decision as the response measure, have shown consistent form-priming effects. Unfortunately, different results emerge depending on the procedure used. With the identification procedure, almost any orthographic overlap between prime and target is sufficient for priming to occur, but with the lexical decision procedure, form priming effects are much more limited in scope. The experiments reported here show that accuracy in the masked identification paradigm is influenced by the legibility of the target stimulus when superimposed on an image of the prime, even though there is no orthographic overlap between the two stimuli. Yet for the lexical decision version of the masked priming procedure there is no difference in latency or error rate as a function of legibility. It is further shown that the presence or absence of the legibility effect has little to do with the nature of the task required of the subject, but is instead a function of the duration of the target--i.e. the legibility effect depends on having the prime and the target both displayed rapidly, and both masked. Failing to take legibility effects into account may lead to problems in interpreting the exact extent of form-priming effects in studies that use the identification procedure.