Contrary to the common forgetting normally occurring in our daily lives, there are some diseases and injuries in the brain that produce severe loss of memory, and may also interfere with the ability to learn. This inability is called amnesia.

Factors that may cause total or partial loss of memory are:

Chronic alcoholism

Brain tumor

Concussion

Encephalitis

Brain traumas may cause loss of memory manifested in two different ways:

Retrograde amnesia. The person will remember things after the trauma, but will forget facts from that moment back to months or even years before.

Anterograde amnesia. The events before the trauma might be remembered, but facts following the trauma will not be remembered. In severe cases, the person might be incapable of learning any new skill, as is the case of a patient who every time he met his physician he would greet him as if it was the first time.

Global transitory amnesia. This is a form of amnesia that lasts a short period of time and involves the anterograde followed by the retrograde amnesia. This type of amnesia is caused by cerebral ischemia (temporary decrease of blood flow).

According to Bear & al., 1996(1), although rare, there are records of this type of amnesia being caused by:

Stress

Car accidents

Soccer

Drugs

Cold baths

Sex

Contd. Human Memory: What it is and How to Improve It
By: Silvia Helena Cardoso, PhD
In: Brain & MInd