Before defining this concept we must define memory. Memory
is the capacity that our Central Nervous System has to apprehend, organize and
fix events from our past and is closely linked to the function of attention. It
is capable of storing data through ultra complex mechanisms that develop in
three stages: encryption, storage and evocation. The presence
of amnesia prevents this ability from developing properly.
the amnesia is determined when it is found that someone has lost
or has weakened the memory. The person suffering from
this disorder is not able to store or retrieve information received
in advance, either for organic or functional reasons.
The organic amnesia involves some type of injury to the
brain area, which can be caused by disease, trauma or abuse of
certain drugs. On the other hand, functional amnesia appears
due to psychological factors, such as a defense mechanism (for example,
post-traumatic hysterical amnesia).
There are also cases of spontaneous amnesia, such as global
transient amnesia (TGA). This disorder is more
common in older men and usually lasts less than twenty hours.
Based on its etiologic classification, amnesia can be traumatic (caused
by head damage and usually transient), dissociative (associated
with long-term repressed memory), lacunar (caused by a specific
event), infantile (inability to recall childhood events), global (total
memory loss), post-hypnotic (when events are forgotten during
hypnosis), psychogenic (for psychological reasons) or source (some
information may be remembered but not where it was obtained).
There is also talk of Korsakoff Syndrome (a type of amnesia
caused by alcoholism), the fugitive state (also defined as
dissociative fugue, which appears due to psychological trauma and is usually
temporary) and the memory mistrust syndrome (where the person
is unable to trust his own memory).
The main causes of amnesia are aging, head injuries, Alzheimer's disease,
excessive alcohol intake, drugs, untreated epilepsy, vitamin deficiency,
malnutrition, hypo or hyperthyroid disease, and high-dose steroid abuse.
Its appearance usually occurs from the age of 30 through blank mind episodes
or repetition of automatic acts (due to stress, anxiety, anguish and
depression). Since the 60s, forgetfulness disorders associated with age have
emerged ("benign senile forgetting"), slight memory disturbances, difficulty in
learning and remembering names, among other things.
To know if a person suffers from amnesia, it is enough to analyze their
symptoms: inability to remember events that occurred recently, a few days ago or
even in distant times such as childhood. The first thing specialists do when
they meet a patient suffering from amnesia is to carry out tests to find out if
there is any type of condition in the brain, if the person has previously
consumed alcoholic beverages or medications such as anti-anxiety drugs.
The vast network of circuits that the nervous system
possesses is so complex that even in many aspects it is still an area of
absolute mystery for scientists and any damage that is caused to it can alter
its normal functioning forever. This occurs with Alzheimer's disease, there are
many people who suffer from it and for years research and search has been done
to find a way to cure it or reduce its consequences, however, it continues to
be unknown territory and full of uncertainty for specialists.
According to the Doctor in Psychiatry Joaquín Fuster, who
carried out a study on the mechanisms of memory and the disorders in its
functioning, the formation of protein plaques in the brain interferes with interneuronal communication, leading
to degeneration of neurons that blocks transmission. of impulses and causes
recent memory loss. He added that these types of disorders are developed due to
a genetic predisposition, so the advance in research on the Human Genome (allows
the identification of genes involved in the development of certain diseases)
could help future diseases such as amnesia, Alzheimer's and
the Parkinson disappear forever.
In the case of amnesias due to psychological causes, they are called dissociative
disorders. They consist of a psychological mechanism through which
memories are inhibited from knowledge if they are linked to very stressful
experiences, such as accidents or psychological trauma experienced during
There are several amnesias of this type: dissociative amnesia (localized:
events of a certain period cannot be remembered, generalized: nothing is
remembered about what happened in life, continuous: inability to remember events
before or after a precise and systematized stage: memory loss in certain aspects
of the information), dissociative leak (due to a confusion
about identity the patient runs away from home or workplace without being aware
that he is doing it; later they are not able to remember what they did in that
state) and dissociative identity disorder(individuals who
alternate two or more identities due to episodes of amnesia. Its causes are
unaffordable stress, abnormal development before a vision of the self and others
consolidate, or a lack of protection in childhood), among others.
Finally, it should be noted that amnesia is a subject very much dealt with in
works of fiction, as in the movie Memento.