Lexical representation in semantic memory and phonological priming effects]

The structure of lexical representations in semantic memory and their processes were investigated through phonological priming effects in lexical decision task. The SOA condition between prime stimuli and target stimuli was varied in three experiments. In each experiment, subjects were 16 graduate or undergraduate students, and 24 three-letter-words (phonologically related/unrelated) or plus signs (neutral) were used as prime, followed by target composed of 12 three-letter-words and 12 three-letter-nonwords. The priming effects occurred in all the experiments, particularly when prime and target shared adjacent two letters. The effects at SOA 400 ms were not stable enough. At SOA 700 ms, only facilitation effects were obtained, but at SOA 1,000 ms, the effects of both facilitation and inhibition were obtained. These results suggested that in lexical representations phonologically similar words were closely related to each other in their structure, and that especially the phonological similarity between the sets of adjacent two letters was important regarding three-letter-words. The results also suggested that it might take longer time to spread activation in lexical representation than in conceptual representation.