The different types of amnesia (and their characteristics)

The amnesia is a disorder that affects the normal functioning of the memory and that makes those who suffer it unable to store information or retrieve it correctly.

However, beyond this brief definition there are many nuances that make us have to talk, more about amnesia as a global concept, of types of amnesia.

Amnesia can take many forms

Amnesia can present itself in so many forms that studies of certain injuries and dysfunctions In different parts of the brain, the mechanisms that operate behind the use of memory have been discovered from 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 in the brain, causing some memories to be blocked. This means that the types of amnesia can also be established by attending to the different causes that produce them. In this way it has been seen that what appears to be a simple cognitive function based simply on the Information storage is actually the result of several processes working at the same time.

In this article we will show the different types of amnesia, their characteristics and criteria by which they can be classified into different categories.

1. Types of amnesia according to their chronology

If we look at the criterion of the chronology in which the amnesia manifests, we will distinguish between two types of amnesia: retrograde and antegrade. This classification only serves to describe the symptoms of amnesia, and does not give information on what causes it. In addition, both types of amnesia can occur at the same time, although one is often more noticeable than the other.

1.1. Retrograde amnesia

In retrograde amnesia unremembered experiences happened before you started to develop this disorder. It is the best known type of amnesia and embodied in series, movies and other works of fiction in which a character does not remember a part of her past.

1.2. Anterograde amnesia

In this type of amnesia there is a total or partial inability to make the experiences that are lived remain fixed in the memory. That is, anterograde amnesia, by affecting what is happening since the disorder first developed, makes what is lived does not become 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, although usually the most important memories related to the own identity will be preserved. Among its most likely causes is the possibility that a traumatic event has altered the normal functioning of the brain.

2.2. Childhood amnesia

Consists in the inability to recall events experienced in childhood. Despite its name, this type of amnesia is not considered a disorder, as it is common and is part of the normal development of the nervous system as it grows older.

2.3. Drug-induced amnesia

A type of amnesia produced by the administration of substances that affect the functioning of the brain causing the events that happen at that moment to not be remembered. It can be a side effect of a drug or it can be the purpose for which a substance has been given 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 the essentials about her identity and will also be able to remember things about the immediate past, but have difficulty accessing memories about what happened just a few minutes ago (anterograde amnesia) and possibly also when it comes to remembering some things pertaining to long-term memory. This will happen to you for 24 hours or less.

2.5. Dissociative amnesia

In dissociative amnesia, you are unable to evoke memories related to highly stressful or traumatic experiences. One of the most interesting types of amnesia.

2.6. Fountain amnesia

In this type of amnesia there are certain data or pieces of information that are more or less well remembered, although one is not able to know what their source is, how it has come to be known about them.

2.7. Lacunar amnesia

The inability to remember what happened during a certain period in which there was no significant peak of stress. It is named this way because it leaves a blank "gap" in memory.

2.8. Post-traumatic amnesia

Post-traumatic or traumatic amnesia is a type of amnesia caused by a blow to the head or a general head injury. It tends to be transitory and to affect memories of the immediate past. Post-traumatic amnesia should not be confused with forms of amnesia that arise from traumatic experiences.

2.9. Dissociative fugue

This type of amnesia, very common in cases of dementia, the person may realize that he is in a place without remembering how he got there. In dissociative fugue, in addition, it is very common that aspects of one's own identity are not remembered, causing the person to undertake a more or less long journey to remember who he is.

2.10. Wernicke-Korsakoff syndrome

Although it is not a type of amnesia per se, the Wernicke-Korsakoff syndrome It is a set of symptoms in which memory disorders play a very important role. Among its most common symptoms is ora combination of retrograde and anterograde amnesia and confabulation, that is, the involuntary invention of stories that serve to "fill in" memory gaps. It is usually caused by alcoholism.