The relationship between lexicon and reading comprehension has been extensively studied in educational contexts. This paper presents the results of a semantic priming test, to verify the effects of age and previous studies on the semantic association of words of disciplinary lexicon. The results indicate that latencies in lexical recognition and association are superior to other related investigations and that, despite the general differences produced by the variables, it is concluded that age and previous studies have a relative impact on lexical decision-making and on the configuration of semantic networks.