the amnesia it is a disorder which affects the normal functioning of memory and makes the patient unable to store information or retrieve it properly.
However, beyond this succinct definition there are many nuances that make us talk, more of amnesia as a whole concept, of types of amnesia.
Amnesia can take different forms
Amnesia can take so many forms that studies of certain injuries and dysfunctions in different parts of the brain led to the discovery of the mechanisms behind the use of memory of the different types of amnesia that occur.
In addition, this phenomenon can be caused by injuries or by the “emotional imprint” that certain experiences have left on the brain, causing certain memories to be blocked. This means that the types of amnesia can also be established by addressing the different causes that produce them. We have thus seen that what appears to be a simple cognitive function based simply on the storage of information is in fact the result of several processes operating at the same time.
In this article we will show the different types of amnesia, their characteristics and the criteria by which they can be classified into different categories.
1. Type of amnesia according to its chronology
If we look at the criterion of the chronology in which the amnesia manifests itself, we will distinguish two types of amnesia: the retrograde and the antegrade. This classification is only used to describe the symptoms of amnesia and does not provide information on the causes of it. In addition, two types of amnesia can occur at the same time, although often one is more noticeable than the other.
1.1. retrograde amnesia
In retrograde amnesia experiences that you don’t remember happened before this disorder started to develop. It is the most well-known type of amnesia and embodied in series, movies and other works of fiction in which a character does not remember part of their past.
1.2. anterograde amnesia
In this type of amnesia there is a total or partial inability to ensure that lived experiences are frozen in memory. In other words, anterograde amnesia, by affecting what happens since the development of the disorder, means that what is experienced is not part of long-term memory and is forgotten after a few minutes or seconds.
An example of this type of amnesia can be seen in the famous movie Memento.
2. Types of amnesia according to their causes
2.1. global amnesia
This type of amnesia consists of the total memory loss, While the most important memories related to his own identity will usually be preserved. Among its most likely causes is the possibility that a traumatic event has impaired normal brain function.
2.2. Infantile amnesia
consists of inability to remember childhood events. Despite the name, this type of amnesia is not considered a disorder because it is common and part of the normal development of the nervous system as it grows.
2.3. Drug-induced amnesia
Types of amnesia produced by the administration of substances that affect the functioning of the brain, making it impossible to remember what is happening at that time. This could be a side effect of a drug or the purpose for which a substance was supplied for therapeutic purposes during, for example, surgery.
2.4. Transient global amnesia
It is not known what causes this type of amnesia, only its symptoms. The person who experiences transient global amnesia will remember most of their identity and will also be able to remember things about the immediate past, but you will have a hard time accessing the memories of what happened just a few minutes ago (Anterograde amnesia) and maybe also when it comes to remembering some things related to long term memory. This will happen to you for 24 hours or less.
2.5. dissociative amnesia
In dissociative amnesia, one is unable to recall memories of very stressful or traumatic experiences. One of the most interesting types of amnesia.
2.6. Source amnesia
In this type of amnesia there is certain data or information that we remember more or less well, Although we cannot know what their source is, how we came to know them.
2.7. Lacunar amnesia
The inability to remember what happened during a period of time when there was no significant stress peak. It is called that because it leaves an empty “void” in the memory.
2.8. Post-traumatic amnesia
Post-traumatic or traumatic amnesia is a type of amnesia produced by a blow to the head or a traumatic brain injury in general. It tends to be transient and affect memories of the immediate past. Post-traumatic amnesia should not be confused with the forms of amnesia that appear as a result of traumatic experiences.
2.9. Dissociative escape
This type of amnesia, very common in cases of dementia, the person may realize that they are in a place without remembering how they got here. In dissociative flight, moreover, it is very common that aspects of their own identity are not remembered, which causes the person to take a more or less long journey to remember who they are.
2.10. Wernicke-Korsakoff syndrome
Although not a type of amnesia per se, Wernicke-Korsakoff syndrome is a set of symptoms in which memory impairment plays a very important role. Among its most common symptoms are youn a combination of retrograde and anterograde amnesia and conspiracyThat is, the unintentional invention of stories that serve to “fill” the gaps in memory. It is usually caused by alcoholism.