Amnesia is one of the most well-known memory disorders, it is a clinical problem that results in significant deficits when it comes to encoding, storing or retrieving information from experiments, so the basic psychological process of memory is complex and multifactorial. Amnesia is, in many cases, a very complicated symptom of explaining accurately.
In this sense, patients with amnesia have been a source of incalculable value when it comes to understanding a little better the functioning of our memory, studying the different deficits that we may encounter helps us to better understand the structure and functionality of memory. The subject has so far been performed on amnesic syndrome, a syndrome in which episodic memory is altered.
- But what is episodic memory? It is the memory of the facts.
- Of everything that has already happened or we know that happened at some point.
- When we study amnesia in this type of memory.
- We do it based on a temporary organization of harm.
- We can organize it into two types: (A) retrograde amnesia.
- Where the loss of memories of everything that happened before the disease or accident.
- And (B) an anograde amnesia?where the loss of the ability to form new memories occurs after an illness or accident We will explain these categories more broadly below.
Retrograde amnesia is characterized by the inability to access memories before the memory injury occurred. The affected time period can be very variable, leading to the forgetting of a few days or a life. It is important to consider the syndromes, disorders and injuries that because this type of amnesia does not affect the ability to create new memories. Are there other types of memory also intact, such as implicit memory?automatic processes such as changing the car’s gear and procedure?a motor memory, like cycling.
The origin and cause of this disorder is usually organic, i. e. it is the result of an injury to brain tissue, specifically in the brain, can be caused by damage to the hippocampus, central gray nucleus or diencephalus. It means, however, that retrograde amnesia cannot occur without any injury. When this happens, it is called psychogenic or functional amnesia.
One of the most studied patients with a case of amnesiac syndrome was Clive Wearing, who did not remember any data prior to an accident he suffered in 1985, which caused him to destroy his hippocampus and severe damage to the temporal lobes. In addition to retrograde amnesia, Clive also suffered from an antegrade amnesia, which did not allow him to create new memories, this patient’s life was supposed to live in a continuous and eternal gift from which he could not escape.
Unlike retrograde disorder, anestrograde amnesia involves the inability to create new memories after injury, so any information stored before the injury remains stored in memory, which remains intact with normal memory phenomena. In cases, the situation is the result of an organic injury, in which hypothalamic and temporal structures are damaged.
A curious feature of this disorder is that only explicit memory coding is damaged, which means that this subject, despite his inability to create new memories, can acquire new procedural or implicit skills, for example, if a patient with anusgrade amnesia plays the piano every day. day, will get better over time, but he won’t consciously remember playing the piano at any time, because for him every day would be the first day.
One of the best-known cases of anusgrade amnesia was HD, an acronym for patient Henry Molaison, one of the first to study the location in the brain of the structures responsible for memory, which had to be operated on to end his severe epileptic seizures. During this surgery, his epileptic home was extracted, only large parts of the hypothalamic structures. In fact, the surgery ended his history of seizures, but it also caused serious memory damage.
HM could not remember anything new after the operation, but his management and procedural skills were intact. When it came to engaging in a conversation with him, it was consistent and at first glance he didn’t seem to have any problems. conversation and came back, I didn’t remember anything.
As we mentioned earlier that all types of amnesia are independent: one can appear without the other appearing, it should be noted in this regard in particular that the reality of amnesia syndrome is much more complex, the most normal is that the lesions affect several areas of the brain, which eventually triggers mixed amnesia. However, studies in these patients with “pure” amnesia are very interesting to learn more about how our memory works.