Forgetting (retention loss) is a spontaneous or gradual process in which old memories are deleted from the memory storage. It is subject to delicately balanced optimization that ensures that only the least relevant memories are deleted, as well as a security process ensuring that dangerous information will not harm us. Forgetting can be prevented by repetition and/or evaluation of the information. As we are examining this part of mind, this function of mind, we shouldn't forget that this is still not an exactly explained property of mind. 2005 : January - February - March - April - May - June - July - August - September - October - November - December- → Deaths in August August 31: Michael Sheard August 26: Lord Fitt August 24: Jack Slipper August 24: Maurice Cowling August 24: Dr. Tom Pashby August 23: Brock Peters August 22: Lord Lane August 21: Robert Moog August... Memory is the ability of the brain to store, retain, and subsequently recall information. ...

Forgetting can have very different causes than simply removal of stored content. Forgetting can mean access problems, availability problems, or can have other reasons such as amnesia caused by accident. Amnesia (or amnaesia in Commonwealth English) is a condition in which memory is disturbed. ...

In addition, information that has been stored may be permanently lost. Any information, to be able to permanently access our nervous system, needs a certain amount of time for biochemical changes to occur; if this amount of time is not given due to a disruption, the information is lost. Disruption can be caused by accidents, brain surgery, certain drugs, etc.; long-term memory is lost during the disruption. (Example: A football player involved in a major injury could remember exactly what had happened immediately after the incident, yet they could not remember it twenty minutes earlier.) The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. ... Biochemistry is the chemistry of life. ... Neurosurgery is the surgical discipline focused on treating the central and peripheral nervous system. ...

A debatable yet popular concept is "trace decay", which can occur in both short and long-term memory. This theory, applicable mostly to short-term memory, is contradicted by the fact that one is able to ride a bike even after not having done so for decades. It is believed that certain memories "trace decay" while others don't. Nevertheless, one thing is certain: sleep right after the memorization process cannot stop trace decay totally, but it can at least diminish it (explaining why it can be good to study shortly before sleep). // Overview Long-term memory (LTM) is memory that can last as little as 30 seconds or as long as decades. ... Short-term memory, sometimes referred to as primary or active memory, is that part of memory which stores a limited amount of information for a limited amount of time (roughly 15-30 seconds). ...

See also

• Amnesia
• Educational psychology