Language center
With Language Center (actually: language centers, including: Broca's area , Wernicke's area ), the areas in the brain referred to which a special role in language processing and production due.
Current state of research
With new functional imaging methods such as PET and fMRI , images can be generated that show areas and their activation status in the living brain. Previously, the research was based primarily on failure symptoms in damage to the cerebral cortex . Research in the areas of language processing has thus undergone a radical turn. It is now known that a number of relatively broadly distributed areas are involved in language processing. More recent research also pays increasing attention to subcortical areas, i.e. areas located below the cerebral cortex in the core area such as putamen and caudate nucleus , as well as premotor (BA 6) regions. In general, it is currently assumed that in addition to the primary and secondary auditory processing areas, the following structures of the cerebral cortex play an essential role in language processing:
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Inferior frontal gyrus
- BA 44: Processing of sentence structure, working memory
- BA 45/47, Brodmann-Areal : Understanding sentences, working memory
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Superior temporal gyrus :
- Anterior part: Morphosyntactic processing : structure of words with prefixes and suffixes, as well as sentence structure
- Posterior part: Integration of syntactic and semantic information: Relates the sentence structure to the meaning of what is spoken
- Gyrus temporalis medius : word semantic processing, meaning of the individual words
Right-handed people mainly involve the areas of the left cerebral hemisphere , whereby bilateral activations, especially in the area of syntactic processing, are not uncommon. It is currently believed that the right hemisphere plays an important role in processing suprasegmental acoustic features such as prosody .
Most language processing areas develop in the language- dominant hemisphere in the second year of life . According to statistical findings, their position is largely independent of personal handedness: The left hemisphere is dominant in 98 percent of right -handers, and also in the majority of left-handers.
Older models
The differentiation into only two large-scale language processing areas (Broca and Wernicke areas), which was assumed for a long time before the advent of functional imaging methods, is considered to be outdated. The Broca area was first assigned a role in linguistic functions in 1861 by the French neurologist and anthropologist Paul Broca . The basis of this discovery was the research of language problems after damage in this brain region, which is located in the lower frontal lobe. Lesions of Broca's area mainly result in disorders of speech production . In contrast, damage to the Wernicke area, which is located in the upper part of the temporal lobe, mainly leads to disorders of speech reception . It is named after the German doctor Carl Wernicke , who discovered it in 1874 while researching aphasia (loss of language skills).
This narrow Broca area is still an important language center today, where syntax , grammar and sentence structure are processed.
Even in this early research it could be shown that the content-related and structural language processing takes place in different brain areas.
See also
literature
- Donald Loritz: How the Brain Evolved Language. Oxford University Press, 1999, ISBN 0-19-515124-0 .
- Angela D. Friederici : Towards a neural basis of auditory sentence processing. In: Trends in Cognitive Sciences. Volume 6, No. 2, 2002, p. 78.
- E. Kaan, TY Swaab: The brain circuitry of syntactic comprehension. In: Trends in Cognitive Sciences. Volume 6, No. 8, 2002, p. 350.
- NF Dronkers, S. Pinker, A. Damasio: Language and the Aphasias. In: ER Kandel, JH Schwartz, TM Jessel (Ed.): Principles of Neuroscience. . 4th edition. McGraw-Hill, New York 2000, pp. 1169-1187.
