Morphological effects on speech production: Evidence from picture naming

The influence of morphologically complex and simple words on the production of morphologically complex and simple picture names was investigated in fi ve picture-word interference studies. Two variants of picture-word interfer ence were employed to separate morphological from semantic and phonological effects. In the first variant, distractor words were presented concurrentl y with the pictures, which had to be named. Semantic distractors produced t he expected interference. Morphological and phonological distractors both r esulted in facilitation, but the size of the effect was much larger for mor phological distractors. In a second variant, distractors and pictures were separated by a lag of 7-10 intervening trials. Picture naming was again fac ilitated by morphological distractors, but no effects were found for phonol ogical and semantic distractors. Distractors from different morphological c lasses were investigated in the last experiment, again with lags between di stractors and pictures. Although these distractors shared a free morpheme w ith the picture name, they differed from the picture at the conceptual and lemma level. Equal amounts of facilitation were obtained for all distractor types, suggesting that effects originate at a level of shared morphemes.