I meccanismi di accesso lessicale e il paradigma di interferenza figura-figura

With the picture-word interference paradigm, four different effects have been observed in bare noun production. Beside the well-known semantic categorical interference and phonological facilitation effect, recently also the frequency of the distracter word (Miozzo & Caramazza, 2003) and the congruity of grammatical gender (Cubelli et al., 2005) have been reported to affect naming times. The aim of this study is to verify whether this effects occur also with the picture-picture paradigm. In three experiments semantic relatedness, gender congruency, phonological similarity, and distracter frequency were manipulated. Participants were asked to name the picture cued by an arrow (appearing on the screen 40 ms. before the picture pairs). In contrast with studies using the picture-word paradigm, results showed only a significant phonological facilitation. This effect suggests that, although irrelevant to accomplish the task, the phonological form of the distracter's name is activated, thus supporting the cascade model of lexical access (Morsella & Miozzo, 2002; Navarrete & Costa, 2005). In contrast, the lack of semantic, grammatical and frequency effects suggests that these effects depend on the format of the distracter and that when the distracter stimulus is a picture no competition occurs at the lexical level. At variance with the picture-word task, where the distracter is processed faster than the target picture, thus leading the corresponding lemma to reach a higher level of activation and to compete for selection, in the picture-picture task the processing of the distracter stimulus is not advantaged and does not interfere with the naming process.