Does amnesia make you forget all your past memories?

Public perception of amnesia is largely based upon Hollywood films (a common theme on this site). In a 2011 survey, 83% of respondents believed that persons suffering from amnesia “cannot recall their own name or identity.”

The first noted use of amnesia as a plot vehicle was all the way back in the silent-movie era. 1915’s “Garden of Lies” featured a new bride who forgets who she is after a car accident. This plot device has enjoyed an almost-constant presence ever since, in notable films such as “50 First Dates,” “Memento,” “Regarding Henry”, “The Long Kiss Goodnight,” “Overboard,” and the Bourne movies starring Matt Damon.

Hollywood’s version of amnesia is often triggered by an accident, such as a sharp blow to the head, or perhaps a psychological trauma. Often a character’s memories suddenly return when they view a certain image, or get a second blow to the head. Characters afflicted with amnesia frequently experience a drastic change in behavioral traits (the trained assassin is now a meek housewife), as if they forgot their personality along with their memories.

There are actually three types of Amnesia:

–        Anterograde Amnesia: Difficulty forming new memories

–        Retrograde Amnesia: Loss of past memories

–        Transient Global Amnesia: Temporary loss of all memory

Anterograde is by far the most common version of amnesia, and does not involve forgetting your past at all. Retrograde does involve the past but probably only a few months (and in some case only the past few minutes, or seconds), and it tends to improve over time. Transient Global Amnesia is uncommon and primarily affects older individuals– research suggests it results from an impaired blood supply, such as after a stroke. This form typically resolves within hours.

Any brain disease or injury, as well as psychiatric illness, can potentially cause amnesia. Head injuries resulting in a complete loss of past memories are, however, extremely rare. And loss of one’s identity – among the most durable of memories – is rarer still. The condition usually improves with medical treatment of the underlying problem, and not, as the movies suggest, by further damaging your brain with a second injury!