While the localizationist view that attributes the understanding of language to the Wernicke region, a region located in the temporal lobe, has prevailed since the end of the 19th century, in recent years the scientific community has shown that the nervous complexity of this uniquely human function is much larger. than previously thought.
In this article we will describe the anatomical structure and functions of the Wernicke region. We will also talk about the most distinctive symptoms of the language disorder associated with lesions in this region of the brain: Wernicke’s aphasia, also called “sensory” or “receptive”.
Anatomy and structure of the Wernicke region
Wernicke’s region is a region of the brain that it is located behind the superior temporal gyrus of the dominant hemisphereUsually the left, with a large number of exceptions among the leftists. The superior temporal gyrus is located near the primary auditory cortex, as well as the outermost parts of this sensory system.
This area of the brain is bordered by the angular rotation of the parietal lobe, involved in language, reasoning and memory. The blood supply to the Wernicke region depends on the middle cerebral artery, which is essential for the transport of nutrients to the cortex as a whole.
There is some disagreement on the exact demarcation of the Wernicke region. While many experts consider you to identify with the anterior part of the Brodmann zone 22 of the temporal lobe (Involved in the recognition of auditory verbal stimuli according to neurofunctional studies), others place it in the multimodal cortex of the parietal gland.
Functions of this brain region
This cortical structure was first described by German neurologist and psychiatrist Carl Wernicke in 1874. This author proposed the existence of a link between the region of the brain to which his name would be given and the production and imitation of oral language. His hypothesis was based on the analysis of lesions of the superior temporal gyrus and its associated signs.
From this milestone in the field of neuroanatomy, the vision of localization that attributes receptive language (i.e. auditory understanding of speech) to the Wernicke region began to consolidate. From this point of view, the region is considered to be the brain center for language comprehension, Or at least a very relevant structure in this function.
Among the cognitive functions associated with the Wernicke region during the 19th and 20th centuries are the semantic processing of linguistic information (both auditory and written), language recognition and its interpretation.
Recent research on language
It is important to mention the relationship between the Wernicke region and the Broca region, Located in the forebrain and traditionally associated with the production of language. It was long believed that the two regions were connected by a set of nerve fibers called the “arched fascicle”.
However, we now know that the arched fascicle actually connects the Wernicke region with the premotor and motor cortex in general, and not just with the Broca region; in any case it would be the uncinado fascicle of the person in charge of this interaction. The findings surrounding the functions of these two regions are even more relevant.
Although language comprehension is traditionally attributed to the Wernicke region, recent neuroimaging studies suggest that this region could be more involved in speech production. Paradoxically, it is also believed today that the Broca region can be mainly linked to the understanding of the language and not to its production.
In any case, it is important to note that brain functions are generally not located in a single brain structure. Likewise, language is a very complex function in which large regions and networks play important roles that primarily, but not exclusively, involve the frontal and temporal lobes.
Symptoms of Wernicke’s aphasia
This often results in injury to the temporal lobe of the dominant hemisphere of the brain a language disorder called “Wernicke’s aphasia” because of its relationship to the area in question. This alteration has also been called “sensory aphasia”, “receptive”, “comprehension” and “fluid” according to its defining characteristics.
People with Wernicke’s aphasia find it difficult to understand the speech of others. In addition, despite being fluid and well articulated, his speech is usually meaningless and full of paraphrases, Or substitutions of phonemes for similar ones. These alterations also occur in written language, which shares a brain base with spoken language.
The similarity of the symptoms of Wernicke’s aphasia to the language alterations that occur in the context of schizophrenia is striking. Thus, in both disorders, we find phenomena such as neologisms (words with no shared meaning) and the lack of consistency of sentences. (Schizophrenia, paragrammatism or word salad).