In recent years, studies in the cognitive neuropsychology of language have helped in understanding the functional architecture of linguistic processes. It has been shown that recognizing, comprehending and producing a word entails the activation of a complex set of mechanisms, each of which can be selectively impaired as a consequence of brain damage. Investigations of aphasic subjects have demonstrated that the meaning, the pronunciation and the spelling of a word are represented independently, that category information plays a critical role in semantic organization, and that the mental vocabulary represents word class and morphological structure. These distinctions in the architecture of the lexical-semantic system, in turn, have provided the basis for PET and fMRI studies of the neural correlates of single-word processing. These experiments, in agreement with recent neurophysiological investigations, suggest that cognitive/linguistic functions are likely to be represented in distributed neural networks often encompassing more than one lobe, rather than in individual, sharply demarcated neural structures.
- Anatomo-clinical correlates of aphasia
- Lexical-semantic disorders
- Theoretical models of language