Neuropsychological evidence for a convergent route model for action.

We present a detailed analysis of the relations between acting, naming, and recognising objects from vision, touch, and verbal labels, in a series of three cases. We demonstrate that: (1) there can be better "use" than gesturing of objects even in a patient with impaired semantic information for the objects; (2) this is contingent on direct proprioceptive feedback in action; and (3) there are impaired gestures to "non-action" parts of objects even when the patients can gesture to names and can identify the objects. These results are consistent with a "convergent route" model of action, which holds that direct, modality-specific associations between objects and actions constrain the retrieval of actions from semantic representations.