Levels of Representation in Number Processing
暂无分享,去创建一个
Numbers can be manipulated mentally in several formats such as Arabic notation, spelled-out numerals, and an abstract quantity representation. Neuropsychological models of number processing have attempted to specify the architecture in which mental representations of numbers are interconnected. McCloskey and his colleagues initially proposed a simple model with a single central abstract quantity representation interfaced by notation-specific input and output modules. Although this model sucessfully accounts for several of the peripheral deficits of number processing, difficulties arise with the hypothesis of an obligatory step of semantic interpretation of numbers. Several problematic cases suggest that there must be direct asemantic processing routes parallel to the semantic processing of numerical quantities. An alternative model, Dehaene and Cohen’s triple-code model, describes both the functional architecture and the neural substrates of number processing. It successfully accounts for many types of numerical deficits, including the peculiar dissociations found in pure alexia, in callosotomy cases, in Gerstmann’s syndrome, and in subcortical acalculias.