Locus of semantic priming effects in speeded naming

The locus of semantic priming effects was examined by measuring onset and r ime durations as well as response latencies of words with consistent and in consistent pronunciations, using the postvocalic naming task. We found that the effect of a semantic prime on naming duration was localized rather tha n spread across the entire word; onset durations were shorter in the relate d condition than in the unrelated condition, but rime durations were equal in the two prime conditions. Moreover, the priming effect on onset duration s was larger for words with inconsistent than for those with consistent pro nunciations. These duration results cannot be accounted for by previous pro posals, but they can be accounted for by models in which phonemes are activ ated in parallel rather than serially from left to right and in which motor programs are based on phonemes rather than syllables. Contrary to previous reports of an interaction of prime and regularity (a factor closely relate d to consistency) on naming Iatency, we found no interaction of prime and c onsistency on response latency. We argue that this conflict is only apparen t and arises because naming latency conflates response latency and initial phoneme duration for some targets.