Aphasias: the main language disorders

Causes, symptoms and possible treatments for aphasias.

One of the reasons why neuropsychology is interesting is that it allows us to see to what extent mental processes that appear to be a single thing are actually the result of many different mechanisms acting at the same time in the human brain. Prosopagnosia, for example, is evidence that a person with the ability to see perfectly well may become unable to recognize human faces.

Although the vision of something that should be familiar and its recognition seem to go hand in hand, a lesion in certain areas of the brain can cause this illusion to vanish by overriding one of these mechanisms and causing the other to continue to function without it.

But this is not only true for basic mental processes related to perception, but also for those related to more abstract thinking. Aphasia, for example, is an example of how certain facets of language use and mastery, and not others, can be altered by certain lesions in the brain.and not others, can be altered as a result of certain lesions in the brain.

What are aphasias?

Aphasias are a group of language disorders caused by brain damage. Unlike other types of language impairment, such as alexia, for example, an aphasia affects both spoken language and speech, aphasia affects both spoken and written language..

A person with aphasia has an impaired ability to use language per se, both in understanding and producing it, even though he or she may not have any perceptual or motor problems that would prevent him or her from hearing or seeing well or moving the muscles of the mouth to speak.

What causes aphasia?

The variety of brain lesions that can trigger the onset of aphasia (or several types of aphasia at the same time) are very varied, because the network of neurons that play a role in the production or comprehension of language is widely distributed..

Aphasias are generally considered to occur when a lesion interrupts the flow of information through which images and thoughts are transformed into linguistic symbols organized according to the structure of language (similar to when we notice that we have a word "on the tip of our tongue") or when this brain damage prevents words heard or read from being transformed into images and thoughts.

However, this is still a matter of debate, as it is not clear to what extent our brain it is not clear to what extent our brain distinguishes between thoughts formulated as part of language and thoughts that exist independently of the languages that are mastered. On the other hand, the concept of "aphasia" is rather abstract. What many patients with language disorders present with are, rather, types of aphasia.

Types of aphasia

From a practical point of view, it is not as useful to talk about the causes of aphasia in general as it is to talk about the different types of aphasia, as this allows us to know what is wrong with the aphasia. this allows us to know what happens to each individual patient.. Moreover, the existence of these different kinds of aphasia allows us to see that language is really a puzzle of different mental processes that we would not normally think of considering separately.

Below you can read about these types of aphasia. you can read what are these types of aphasias.

Broca's aphasia

People with Broca's aphasia have more difficulty producing language than understanding it. They have a hard time writing and speaking, take a long time to choose the words they want to say, and also have trouble pronouncing the words. and modulate the tone of voice. The symptoms of this type of aphasia can be detected even by someone who does not understand the patient's language.

Although they have less difficulty understanding texts or spoken language compared to their ability to speak and write, people with Broca's aphasia will be unable to repeat verbatim the phrases or words they hear. will be unable to repeat verbatim the sentences or words they hear, regardless of whether they understand them or not.regardless of whether or not they understand them.

An example of a fictional character who exhibits symptoms similar to the classic picture of Broca's aphasia is Hodor, from the series Game of Thrones and the Song of Ice and Fire books: although he seems to understand what is said to him, his ability to speak is almost completely nullified.

Wernicke's aphasia

In contrast to the previous type of aphasia, in Wernicke's aphasia Speech is fluent and it is easy to speak at a normal rate or even very fast, maintaining correct pronunciation and intonation..

However, usually the sentences or words produced by a person with Wernicke's aphasia are not well constructed, since many times words are replaced by others belonging to the same semantic field (for example, replacing "oven" by "washing machine"), some phonemes are changed by others (changing "gato" by "gado") or sentences are constructed with great syntactic failures in which nothing can be understood because there is no proper structure and verbs have been replaced by adverbs, nouns by articles, etc.

Moreover, in this type of aphasia in this type of aphasia the comprehension of oral and written language is quite altered, as well as the ability to repeat words.as well as the ability to repeat words.

Conduction aphasia

If in Broca's and Wernicke's aphasia the lesion affects the areas related, respectively, to language production and the organization of language to form meaningful units, in conduction aphasia the brain damage affects the networks of neurons that connect these two nuclei of the brain.

That is why a patient with this type of aphasia will have fluent speech and his ability to understand language will be preserved in a relatively good state, but he will not be able to repeat words or phrases verbatim. will not be able to repeat literally the words or phrases he hears and sees written.In order to be able to do so, the circuits that lead from the part of the brain where the word or phrase is recognized as a meaningful whole to the part of the brain where this information is "translated" into speech or writing instructions must be intact.

In addition, in this type of aphasia, the sentences produced also tend to present improper substitutions of phonemes and words.

Global aphasia

Another type of aphasia is global aphasia. It consists of a generalized language impairment that severely affects both language production and comprehension.. Generally, people with this syndrome are also unable to repeat words or phrases, and in some cases will only be able to say one or a few syllables or words which they will repeat regardless of the context.

Transcortical aphasia

The transcortical aphasias are characterized by preserving the ability to repeat phrases and words, something that did not occur in the four previous types of aphasia.

Transcortical motor aphasia

In this syndrome there are symptoms similar to those of Broca's aphasia, with non-fluent speech and the ability to comprehend language more preserved, but adding the possibility of repeating the sentences they hear or read, no matter how long they may be.. That is, someone with motor transcortical aphasia is not able to speak spontaneously, but can repeat anything.

Transcortical sensory aphasia

This is similar to a version of Wernicke's aphasia in that you can repeat what you hear, but not what you read. In addition, sometimes all kinds of syllables or words that have been heard are repeated involuntarily.a phenomenon known as echolalia.

Transcortical mixed aphasia

This type of aphasia is similar to a mild version of global aphasia in which the ability to repeat is preserved, although it is not understood. the ability to repeat is preserved, although what is being said is not understood.. Among the typical symptoms of this type of language impairment, echolalia is also common.

Anomic aphasia

In contrast to the other types of aphasia, in the anomic aphasia both language production and comprehension may be near normal, and the main symptom is anomia. its main symptom is the anomiathat is, difficulty in finding the right words to say something. People with anomic aphasia tend to use many generic terms such as "thing", "that", etc.

Occasionally these difficulties lead them to use circumlocutions, to try to explain themselves again using alternative phrases, or to lengthen what is being said to try to build up details and clues about what is being said.

Language is more complicated than it seems

It is not always easy to identify the types of aphasia that some patients present, as the symptoms can vary greatly and be more complex. symptoms can vary greatly and be more or less severe.However, in all of them (except in the global one) it is clear that behind the use of language there are many parts of the brain more or less specialized in a task and coordinating with each other so that everything works as it should.

Therefore, certain capacities may be lost while others, closely related to the former, are preserved.