The paper reports the on-going research for applying psycholinguistic resources to building and extending semantic networks. We survey different kinds of information that can be extracted from a Word Association Thesaurus (WAT), a resource representing the results of a large-scaled free association test. In addition, we give a comparison of WAT and other language resources (e.g. text corpora, explanatory dictionaries) from the viewpoint of the quality and quantity of semantic information they provide.