BRAIN: LOCALISATION
المؤلف:
John Field
المصدر:
Psycholinguistics
الجزء والصفحة:
P48
2025-08-03
397
BRAIN: LOCALISATION
Early research suggested that there are two areas of the brain which are closely associated with language. Broca’s area (after Paul Broca, 1824–80) lies just in front of and above the left ear. Wernicke’s area (after Carl Wernicke, 1848–1904) is just above and behind the left ear. See Figure B1 under Brain. Attention was first drawn to these parts of the brain by the aphasic effects which were noted when they suffered damage. Generalising considerably, Broca’s aphasia appeared to give rise to problems of syntax while Wernicke’s aphasia resulted in problems of lexis and of comprehension. However, the effects of damage varied greatly in type and degree between patients, suggesting a more complex state of affairs. It is also, of course, dangerous to theorise about normal processing on the basis of evidence from medical cases.
Recently, brain imaging methods have added greatly to our knowledge:
Language appears to be widely distributed throughout the brain. A critical role is played by the system of massive interconnections which enables information to be transmitted rapidly from one part to another. There is evidence that the classic language areas (Broca’s and Wernicke’s) are points where various language processes overlap; their vulnerability thus lies in the fact that many processes pass through them.
Language appears to be organised hierarchically, with the central parts of the brain looking after more rapid analytic operations and the outer looking after slower, associative operations.
There appear to be distinct language processes according to the physical form of the signal (speech vs writing); the way in which the signal is to be handled (e.g. repeating words, finding vocabulary, associating meanings); and whether production or reception is involved. Low-level listening is not as closely connected to speech as some hypothesised.
There is evidence that (at least in detecting errors) there are strong links between syntax and semantics.
Activities involving the form of words (e.g. mnemonic tasks) seem to activate different parts of the brain from those involving word meaning.
Grammar appears to be widely distributed throughout the brain. Function words are stored and processed separately from lexical words. They seem to be processed rapidly, perhaps so as to provide a syntactic frame for the sentence. Regular past forms seem to be processed morphologically while irregular ones are processed as lexical items.
Comparative studies of aphasia across languages suggest that syntactic parsing draws on different areas of the brain according to whether a language is heavily dependent upon word order (like English) or on morphology (like Italian). English speakers suffer especially as a result of damage to Broca’s area; Italian as a result of damage to Wernicke’s area. Hence a view that language processes map in an opportunistic way on to whichever brain functions best support them.
See also: Aphasia, Brain imaging, Function word processing, Modularity1, Syntactic parsing
Further reading: Deacon (1997); Posner and Raichle (1994)
الاكثر قراءة في Linguistics fields
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