Language center
Definition
The language center in the traditional sense is not one, but two regions in the cerebral cortex, i.e. in the central nervous system.
The so-called motor language center, also called Broca area after its first description, and the sensory language center, also called Wernicke area.
Nowadays, however, it is becoming increasingly clear that not only these two regions in the brain are involved in language production and processing, but that numerous other areas also play an important role in the complex processes of language understanding and production.
However, the aim of this article is to look at the two main language centers.
Anatomy of the motor language center
Synonym: Broca area
The motor language center is in the Frontal lobes (Frontal lobe) of Brain in the area of the inferior frontal gyrus. So it borders on at the bottom Temporal lobe (Temporal lobe) at.
In relation to the Brodman areas, it is in the area of areas 44 and 45.
The language center is not present on both sides, but only on one half of the brain, namely the so-called dominant hemisphere.
For a majority of people, this is the case left hemisphere.
As a rough rule, the dominant hemisphere for right-handers is usually on the left, for left-handers it can be on the left or right.
On the Arcuate fasciculus, a strand of nerve fibers, represents Broca's area with that which is also essential for language Wernicke area in connection.
Nerve fibers run from Broca's area in the direction of the motor cerebral cortex (Motocortex), which is also located in the frontal lobe.
This requires that there are further switchings for the language important muscles be controlled, in particular those in the area of the larynx and throat and the facial muscles.
Function of the motor language center
It is believed that the Broca area is responsible for that Speech production.
Especially Sentence structure and grammar seem to be processed and processed here. The language is formed here in terms of wording and syntax.
But contrary to earlier assumptions, the motor language center not only plays a role in language formation but also in Language comprehension.
It used to be assumed that one could clearly distinguish between language production in the Broca area and language understanding in the Wernicke area. Today this assumption is questionable.
Rather, language arises centrally through the interaction of both centers and other smaller regions in the brain.
clinical understanding of the motor language center
Lesions in the area of the motor language center are called Broca's aphasia designated. Aphasia means something like speechlessness.
Broca's aphasia has characteristic symptoms that distinguish it from Wernicke aphasia (see below) make possible.
Those affected can still understand what has been spoken and read, but they can only speak clearly more difficult.
Depending on the extent of the damage, the patient can no longer form individual words or speech production fails completely.
Typical symptoms of Broca's aphasia include:
- the formation of new, not meaningful words (Neologisms)
- speaking short, broken sentences (Telegram style)
- the almost complete lack of grammatical sentence structure (Agrammatism).
Speech production is clearly slowed down, strained and articulation is often indistinct.
It should be noted that Broca's aphasia is not due to the paralysis of Muscles, which are essential for speech production, comes about. The disturbances that those affected show when speaking are similar in the Write available.
Anatomy of the sensory language center
Synonym: Wernicke area
The Wernicke Language Center is located in the upper part of the Temporal lobe.
It is called secondary auditory cortex and is located in Brodman areas 22 and 42.
It is directly adjacent to that primary auditory cortex which can be found in the area of the Heschl cross windings.
Like the Broca area, the Wernicke center only exists in the dominant hemisphere, mostly the left hemisphere.
In the non-dominant hemisphere, the secondary auditory cortex takes on other tasks.
The secondary auditory cortex is closely networked with the primary auditory cortex via nerve fibers, from which the information about what is heard from the periphery (the hearing organ, the cochlea) arrived.
Furthermore, the secondary auditory cortex is associated with the Angular gyrus connected. This has a central role in the Linking what you see with language as it is of great importance when reading and writing, for example.
Accordingly, the angular gyrus receives its information mainly from the Visual cortex, the visual cortex, whereupon these are processed and forwarded to the Wernicke center.
The Wernicke area dismisses, among other things, via the Arcuate fasciculus Fibers to Broca's area. The two language centers are therefore closely related to each other.
Function of the sensory language center
The Wernicke area plays an immense role in Language comprehension.
This means that it's not just for the interpersonal communication but also plays a role Thought processes of an individual, since these also largely run through linguistic formulations.
clinical understanding of the sensory language center
A lesion in the area of Wernicke's area with speech impairment is called sensory or Wernicke aphasia designated. Here is that Language comprehension clearly disturbed.
The patients speak - in contrast to patients with Broca's aphasia - often liquid and a lot (Logorrhea) and in normal sentence melody, but often incomprehensible words.
Sentences and grammar usually no longer make sense either. They use semantic and phonematic paraphasias.
Semantic Paraphasias describe a mix-up of words from a similar group of meanings, for example table instead of chair.
Phonematic Paraphasias are word formation (Neologisms), some of which still give an idea of the word originally intended (for example Bulme instead of Blume), but sometimes also no longer allow conclusions to be drawn about the original word.
In contrast to Broca's aphasia, the patients with Wernicke's aphasia mostly do not notice that something is wrong with their language, so they do not understand why the other person is not reacting adequately.
A lesion of the secondary auditory cortex in the area of the non-dominant hemisphere however, it does not impair speech understanding, since the Wernicke language center is only present on one side, in the dominant hemisphere of the brain.
A disorder in the non-dominant hemisphere of the brain leads to, among other things Loss of understanding and recognition of music.
Damage to the Angular gyrus, which connects the secondary auditory cortex with the visual cortex, usually has reading disorders (Alexia) and writing (Agraphy) result.
In addition, those affected are often unable to name objects that are shown to them, and they are then laboriously described in other words. For example, the pen becomes something you write with.
The language center is therefore a complex network that has its two main organs in the frontal lobe and temporal lobe and is connected to other areas of the brain via numerous nerve fibers. Certainly nowadays the origin of language is still not understood in all its complexity.
