Language: cognitive models and functional anatomy

The first section of this chapter introduces cognitive neuropsychological models of single word processing. It compares this approach with a number of competing theoretical perspectives. The second section considers how language is represented in the brain. The classical Wernicke-Lichtheim model, although widely represented in textbooks, is inadequate. This section considers evidence from lesion studies of people with brain damage together with their limitations. Although functional imaging studies have brought substantial progress in the understanding of language representation in the brain, much is still unclear about the nature of processing taking place, how it is implemented at a neural level and the interactions between different regions during language tasks. The first section of this chapter introduces cognitive neuropsychological models of single word processing. Box and arrow models can indicate the functional architecture of the language system but provide only a first level of description; they need to be supplemented by detailed descriptions of how the modules operate. They are however very useful clinically in guiding a description of different levels of impairment, and identifying intact language abilities. This approach is then compared with a number of competing theoretical perspectives.