In the study of

language processing Language processing refers to the way humans use words to communicate ideas and feelings, and how such communications are processed and understood. Language processing is considered to be a uniquely human ability that is not produced with the sa ...

Carl Wernicke Carl (or Karl) Wernicke (; ; 15 May 1848 – 15 June 1905) was a German physician, anatomist, psychiatrist and neuropathologist. He is known for his influential research into the pathological effects of specific forms of encephalopathy and also ...

created an early neurological model of language, that later was revived by

Norman Geschwind Norman Geschwind (January 8, 1926 – November 4, 1984) was a pioneering American behavioral neurologist, best known for his exploration of behavioral neurology through disconnection models based on lesion analysis. Early life Norman Geschwi ...

. The model is known as the Wernicke–Geschwind model. # For listening to and understanding spoken words, the sounds of the words are sent through the auditory pathways to

area Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while '' surface area'' refers to the area of an ope ...

41, which is the primary

auditory cortex The auditory cortex is the part of the temporal lobe that processes auditory information in humans and many other vertebrates. It is a part of the auditory system, performing basic and higher functions in hearing, such as possible relations to ...

(

Heschl's gyrus The transverse temporal gyri, also called Heschl's gyri () or Heschl's convolutions, are gyri found in the area of primary auditory cortex buried within the lateral sulcus of the human brain, occupying Brodmann areas 41 and 42. Transverse tempo ...

). From there, they continue to

Wernicke's area Wernicke's area (; ), also called Wernicke's speech area, is one of the two parts of the cerebral cortex that are linked to speech, the other being Broca's area. It is involved in the comprehension of written and spoken language, in contrast to B ...

, where the meaning of the words is extracted. # In order to speak, the meanings of words are sent from Wernicke's area via the

arcuate fasciculus The arcuate fasciculus (AF) is a bundle of axons that generally connects the Broca's area and the Wernicke's area in the brain. It is an association fiber tract connecting caudal temporal cortex and inferior frontal lobe. ''Fasciculus arcuatus'' i ...

Broca's area Broca's area, or the Broca area (, also , ), is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production. Language processing has been linked to Broca's area since Pierr ...

, where

morphemes A morpheme is the smallest meaningful constituent of a linguistic expression. The field of linguistic study dedicated to morphemes is called morphology. In English, morphemes are often but not necessarily words. Morphemes that stand alone a ...

are assembled. The model proposes that Broca's area holds a representation for articulating words. Instructions for speech are sent from Broca's area to the facial area of the

motor cortex The motor cortex is the region of the cerebral cortex believed to be involved in the planning, control, and execution of voluntary movements. The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately ...

, and from there instructions are sent to facial motor neurons in the brainstem, which relay movement orders to

facial muscles The facial muscles are a group of striated skeletal muscles supplied by the facial nerve (cranial nerve VII) that, among other things, control facial expression. These muscles are also called mimetic muscles. They are only found in mammals, al ...

. # In order to

read Read Read may refer to: * Reading, human cognitive process of decoding symbols in order to construct or derive meaning * Read (automobile), an American car manufactured from 1913 to 1915 * Read (biology), an inferred sequence of base pairs of ...

, information concerning the written text is sent from visual areas 17, 18, and 19 to the

angular gyrus The angular gyrus is a region of the brain lying mainly in the posteroinferior region of the parietal lobe, occupying the posterior part of the inferior parietal lobule. It represents the Brodmann area 39. Its significance is in transferring vis ...

(area 39) and from there to Wernicke's area, for silent reading or, together with Broca's area, for reading out loud. This model is now obsolete. Nevertheless, it has been very useful in directing research and organizing research results, because it is based on the idea that language consists of two basic functions: comprehension, which is a sensory/perceptual function, and speaking, which is a motor function.
However, the neural organization of language is more complex than the Wernicke–Geschwind model of language suggests. The localization of speech in Broca's area is one of the weakest points of this model.Kolb & Whishaw: ''Fundamentals of Human Neuropsychology'', 2003

References

External links

* http://www.umich.edu/~psycours/345/lecture11/sld025.htm {{DEFAULTSORT:Wernicke-Geschwind model Psychoacoustics Neurolinguistics