Hypermnesia is a syndrome characterized by exceptional memory. Autobiographical hypermnesia or hyperthymesis, rare, engenders the ability to remember very precisely and effortlessly each day of his life from a specific moment in his childhood. The causes of hypermnesia remain uncertain, but recent research shows the presence of abnormally strengthened connections in certain regions of the brain of people with this syndrome.

Definition of hypermnesia

Hypermnesia is a syndrome characterized by exceptional memory, due to intense activity in certain areas of the brain.

Types of hypermnesias

There are different types of hypermnesia:

• Autobiographical hypermnesia or hyperthymesis – from Greek thymesis, remember: this type of hypermnesia engenders the exceptional ability to remember very precisely and effortlessly each day of one’s life from a specific moment in one’s childhood;
• Late paroxysmal emotional hypermnesia or post-traumatic stress disorder: a traumatic scene in a patient’s life resurfaces and is relived as if it were happening live in front of them;
• A particular hypermnesia also affects some people with an autism spectrum disorder who can memorize very precisely almost an entire book or a scene in great detail.

Causes of hypermnesia

The causes of hypermnesia remain uncertain. Recent research shows, however, that it probably results from abnormally reinforced connections in certain regions of the brain such as the amygdala and the hippocampus. But researchers are still wondering about the origin of these neuro-functional differences which could as well be the consequence of hypermnesia and not its cause.

Diagnosis of hypermnesia

Magnetic resonance imaging makes it possible to observe the different brain structures and their possible overdevelopments.

People affected by hypermnesia

Only a few dozen people around the world are diagnosed with hyperthymesis today.

Factors promoting hypermnesia

A traumatic scene experienced can lead to late paroxysmal emotional hypermnesia.

Autobiographical memory

Hyperthymia engenders the ability to remember very precisely and effortlessly each day of one’s life from a specific point in one’s childhood. Listening to a date, the hyperthymésic remembers perfectly the D-day and all the personal events which marked out this day. This highly superior autobiographical memory turns out to be a real burden on the brain.

Obsession with memories

People with hyperthymesis often have symptoms of obsessive-compulsive disorder (OCD) in parallel: like the compulsive hoarding of objects, they accumulate memories. They also have an irrepressible need to organize their environment.

Neurosis

Symptoms of late paroxysmal emotional hypermnesia or post-traumatic stress disorder are affective and emotional. Many former deportees from Nazi camps suffer from this syndrome.

Other symptoms

• Aggressiveness;
• Anguish ;
• Paranoia;
• Frigidity;
• Recurring nightmares.

Apart from psychological support, there is currently no treatment for hypermnesia.

There is no way to prevent hypermnesia.