Repetition priming and frequency attenuation in lexical access.

Abstract

Repetition priming effects in lexical decision tasks are stronger for low-frequency words than for high-frequency words. This frequency attenuation effect creates problems for frequency-ordered search models that assume a relatively stable frequency effect. The suggestion is made that frequency attenuation is a product of the involvement of the episodic memory system in the lexical decision process. This hypothesis is supported by the demonstration of constant repetition effects for high- and low-frequency words when the priming stimulus is masked; the masking is assumed to minimize the influence of any possible episodic trace of the prime. It is further shown that long-term repetition effects are much less reliable when the subject is not required to make a lexical decision response to the prime. When a response is required, the expected frequency attenuation effect is restored. It is concluded that normal repetition effects consist of two components: a very brief lexical effect that is independent of frequency and a long-term episodic effect that is sensitive to frequency. There has been much recent interest in the fact that in a lexical decision experiment, where subjects are required to classify letter strings as words or nonwords, there is a substantial increase in both the speed and the accuracy of classificatio n for words that are presented more than once during the experiment, even though considerable time may have elapsed between successive presen