Abstract

We evaluate the computational model of lexical access proposed by Dell, Schwartz, Martin, Saffran, and Gagnon (1997). They argue that fits of their model to naming data obtained from normals and brain-damaged patients support assumptions regarding interactivity in the lexicon, global damage in aphasia, and continuity between normal and aphasic naming behavior. Our investigation reveals that the model fits the empirical data poorly and that the claims Dell et al. make on the basis of the model's performance would not follow even if the model were accurate. Although we improve the model's fit using a novel automatic regression procedure, it cannot account for five of Dell et al.'s twenty-one patients (24%), and we show that its limitations are inherent in its design. We argue that claims such as those made by Dell et al. can only be addressed by considering evidence from multiple related tasks and by comparing multiple computational models. (Caution: This is a preprint. Ple...

Citations