Communication in humans activates almost every part of the brain. Of course, the use of language predominates, but other\ncognitive functions such as attention, memory, emotion, and executive processes are also involved. However, in order to explain\nhow our brain â??understands,â? â??speaks,â? and â??writes,â? and in order to rehabilitate aphasic disorders, neuroscience has faced the\nchallenge for years to reveal the responsible neural networks. Broca and Wernicke (and Lichtheim and many others), during the\n19th century, when brain research was mainly observational and autopsy driven, offered fundamental knowledge about the\nbrain and language, so the Wernicke-Geschwind model appeared and aphasiology during the 20th century was based on it. This\nmodel is still useful for a first approach into the classical categorization of aphasic syndromes, but it is outdated, because it does\nnot adequately describe the neural networks relevant for language, and it offers a modular perspective, focusing mainly on\ncortical structures. During the last three decades, neuroscience conquered new imaging, recording, and manipulation techniques\nfor brain research, and a new model of the functional neuroanatomy of language was developed, the dual stream model,\nconsisting of two interacting networks (â??streamsâ?), one ventral, bilaterally organized, for language comprehension, and one\ndorsal, left hemisphere dominant, for production. This new model also has its limitations but helps us to understand, among\nothers, why patients with different brain lesions can have similar language impairments. Furthermore, interesting aspects arise\nfrom studying language functions in aging brains (and also in young, developing brains) and in cognitively impaired patients\nand neuromodulation effects on reorganization of brain networks subserving language. In this selective review, we discuss\nmethods for coupling new knowledge regarding the functional reorganization of the brain with sophisticated techniques capable\nof activating the available supportive networks in order to provide improved neurorehabilitation strategies for people suffering\nfrom neurogenic communication disorders.
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