Carl Wernicke created an early neurological model of language, that later was revived by Norman Geschwind

Norman Geschwind

Norman Geschwind pioneered behavioral neurology in America. He is best known for his exploration of behavioral neurology through disconnection models based on lesion analysis.- Early life :...

. The model is known as the Wernicke–Geschwind model.

1. For listening to and understanding spoken words, the sounds of the words are sent through the auditory pathways
   Auditory system
   The auditory system is the sensory system for the sense of hearing.- Outer ear :The folds of cartilage surrounding the ear canal are called the pinna...
   
    to area
   Brodmann area
   A Brodmann area is a region of the cerebral cortex defined based on its cytoarchitectonics, or structure and organization of cells.-History:...
   
    41, which is the primary auditory cortex (Heschl’s gyrus
   Transverse temporal gyrus
   The transverse temporal gyri are found in the area of primary auditory cortex in the superior temporal gyrus of the human brain, occupying Brodmann areas 41 and 42. It is the first cortical structure to process incoming auditory information...
   
   ). From there, they continue to Wernicke’s area, where the meaning of the words is extracted.
2. In order to speak, the meanings of words are sent from Wernicke’s area via the arcuate fasciculus
   Arcuate fasciculus
   The arcuate fasciculus is the neural pathway connecting the posterior part of the temporoparietal junction with the frontal cortex in the brain and is now considered as part of the superior longitudinal fasciculus..-Neuroanatomy:...
   
    to Broca’s area, where morphemes 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
   Motor cortex
   Motor cortex is a term that describes regions of the cerebral cortex involved in the planning, control, and execution of voluntary motor functions.-Anatomy of the motor cortex :The motor cortex can be divided into four main parts:...
   
   , and from there instructions are sent to facial motor neurons in the brainstem, which relay movement orders to facial muscles.
3. In order to read, information concerning the written text is sent from visual areas 17, 18, and 19 to the angular gyrus
   Angular gyrus
   The angular gyrus is a region of the brain in the parietal lobe, that lies near the superior edge of the temporal lobe, and immediately posterior to the supramarginal gyrus; it is involved in a number of processes related to language, mathematics and cognition...
   
   (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.