Word frequency effect on repetition priming as a function of prime duration and delay between the prime and the target.

Two experiments studied the necessary conditions for the occurrence of repetition priming and word frequency effect on priming in a lexical decision task. To examine the role of prime processing duration, the prime was presented either for 50 ms or for 700 ms, and an interfering task was introduced between the prime and the target in order to restrict the time during which the prime was effectively processed and to limit it to exactly 50 ms or 700 ms. The interstimulus interval (ISI) between the prime and the target was 1500 ms or 3000 ms in Expt 1, and 600 ms in Expt 2. With primes presented for 50 ms, repetition priming effects were not dependent on target frequency, decreased with an increase of the ISI, and were no longer significant with an ISI of 3000 ms. With primes presented for 700 ms, repetition priming was systematically larger for low-frequency words than for high-frequency words, and remained reliable even with an ISI of 3000 ms. Thus, a minimum of prime duration was required both for maintaining repetition priming effects over more than some hundreds of milliseconds and for the occurrence of frequency effect on repetition priming. Theoretical interpretations of these results are discussed.