Phonological priming reflects lexical competition.

A phonological relationship between a prime and a target produces facilitation when one or two initial phonemes are shared (low-similarity facilitation) but produces interference when more phonemes are shared (high-similarity interference; Slowiaczek & Hamburger, 1992). Although low-similarity facilitation appears to be a strategic effect (Goldinger, Luce, Pisoni, & Marcario, 1992), this result cannot generalize to high-similarity interference because the two effects are dissociated (Slowiaczek & Hamburger, 1992). In the present study, strategic processing in high-similarity interference was investigated. The phonological relatedness proportion (PRP) and the prime-target interstimulus interval (ISI) were varied in a shadowing experiment. Low-similarity facilitation was found only with a high PRP and long ISI, but high-similarity interference was found regardless of PRP and ISI. These results suggest that strategies influence low-similarity facilitation, but high-similarity interference reflects automatic processing.