DERIVATIONAL MORPHOLOGY AND ACCESS TO THE LEXICON - THE CASES OF PREFIXED AND PSEUDO-PREFIXED VERBS

The subject of this research is the role played by the morphological s tructure in the process of access to the lexicon. Although a lot of re search has been conducted on this topic, experimental data on this rol e remains inconsistent. To appreciate the issue, the task of lexical d ecision is used with verbal material constituted by prefixed or pseudo -prefixed verbs as well as visually introduced pseudo-verbs. The natur e of the radical (verb, noun or verb and noun) constitutes a specific factor yielding three types of prefixed structure (prefix - radical ve rb, prefix - radical noun, prefix - radical potentially noun or verb). Two types of pseudo-prefixed structures are studied In function of th e nature of the pseudo-radical (existing or imaginary word). Subjects are submitted to two tests: a lexical decision test for the complete s et of verbal material; a second test (to be taken subsequently) in whi ch they are asked to check from a list the words they believe they hav e seen on the screen in the first test. Results indicate an effective morphological structure and that the processing of prefixed verbs is d one according to the nature of the radical. Verbs with radicals that c ould be verbs and nouns are processed faster than those for which the radical is a verb. The second test also tends to indicate that the mor phological structure is taken into account, and especially that the ra dical is activated at a certain point in the processing (certain radic als, if presented separately are checked as being present in the first test where only the prefixed items containing them were present). Res ults obtained with pseudo-verbs show an Important role played by the p refix in the identification of morphologically complex Items. These re sults only match partially the Taft & Forster Model (1975). Illustrati ng the role played by the nature of the radical allows, to a certain d egree, reconciling contradictory results in the literature. In fact, i t is demonstrated that the different results from various experiences can be explained if this factor is taken into account. The number of p refixed items of each type (defined by the nature of the radical) can thus explain why certain studies reflect differences between morpholog ically simple and complex words and other discard them.