Cognitive neuropsychology. Resolving enigmas about Wernicke's aphasia and other higher cortical disorders.

Cognitive neuropsychology is a young branch of neuroscience whose ancestral influences include a rich pool of experimental (eg, cognitive, psychology), theoretical (eg, epistemology), and clinical (eg, neurology, neuropsychology) disciplines. An essential principle of cognitive neuropsychology is that disorders of higher cortical functions can be understood in terms of breakdowns of one or more information-processing modules. Each module is the most basic element of intelligence that can be defined based on current knowledge. This approach is a refinement of-not a fundamental departure from-the 19th-century "localizationist" view of language disorders. Wernicke's aphasia, for example, classical attributed to a single cognitive deficit (loss of word sounds), is shown in this review to require damage to multiple distinct information-processing modules. Cognitive neuropsychology provides the tools for the type of fine-grained analyses of behavior that are needed to capitalize on recent advances in neuroimaging techniques, including the development of more sophisticated models of brain-behavior relationships.