ABSTRACT
The structure of the argument that has been developed against the sensory/motor theory is not new: Arguments of the same structure have been articulated against the basic assumptions of the sensory/ functional theory by a number of authors. For example, some sensory/functional theorists have proposed that the specific type of visual/perceptual information required in order to recognise fruit/ vegetables consists of knowledge of their colour (e.g., Humphreys & Forde, 2001). If we interpret this claim literally and in its strongest form, the prediction is made that a deficit for knowledge of object colour must be associated with a disproportionate deficit for fruit/vegetables. Notice that any weaker interpretation of the proposal renders it unable to account for a category-specific deficit for fruit/vegetables. Evidence contrary to this proposal has been reported by Miceli, Fouch, Capasso, Shelton, Tomaiuolo, and Caramazza (2001): Patient IOC presented with intact colour perception but impaired knowledge of the colours associated with objects. IOC did not present with a disproportionate deficit for fruit/vegetables compared to other semantic categories. These data indicate that the existence of category-specific deficits for fruit/vegetables cannot be explained in terms of an impairment to knowledge of object colour. Similarly with respect to the sensory/ motor theory: Patient WC was impaired for both producing and recognising the correct movements associated with the actual use of objects, but was unimpaired for conceptual knowledge of objects across a wide range of tests. This indicates that it cannot be the case that conceptual knowledge of tools is distributed over sensorimotor representations.
