Noun-verb differences? A question of semantics: A response to Shapiro and Caramazza

We presented a new model using the sensory/functional theory of semantic category deficits to explain noun/verb deficits in aphasia. The predictions arising from this model were tested on a small number of patients exhibiting grammatical and/or semantic category specific deficits in picture naming. The results lent support for the theory presented. Shapiro and Caramazza (this issue) raised several objections to this theory (which they call the "extended sensory functional theory," or ESFT). In this article we address their concerns about the validity of the ESFT and conclude that it is indeed a useful model that provides a parsimonious explanation for many diverse patterns of deficits.