A SPREADING-ACTIVATION THEORY OF LEMMA RETRIEVAL IN SPEAKING

This paper presents a spreading-activation theory of conceptually driv en lemma retrieval - the first stage of lexical access in speaking. wh ere lexical items specified with respect to meaning and syntactic prop erties are activated and selected. The mental lexicon is conceived of as a network consisting of concept, lemma, and word-form nodes and lab elled links, with each lexical concept represented as an independent n ode. A lemma is retrieved by enhancing the activation level of the nod e representing the to-be-verbalized concept. This activation then spre ads towards the lemma level, and the highest activated lemma node is s elected. The theory resolves questions such as the hypernym problem (L evelt. 1989.). Furthermore, a computer model that implements the theor y is shown to be able to account for many basic findings on the time c ourse of object naming, object categorization, and word categorization in the picture-word interference paradigm. In addition, non-trivial p redictions regarding the time course of semantic facilitation for hype rnyms, hyponyms, and cohyponyms are experimentally tested, and shown t o be valid.