Forgetting (retention loss) refers to apparent loss of information already encoded and stored in an individual's long term memory. It is a spontaneous or gradual process in which old memories are unable to be recalled from memory storage. It is subject to delicately balanced optimization that ensures that relevant memories are recalled. Forgetting can be reduced by repetition and/or more elaborate cognitive processing of information. Reviewing information in ways that involve active retrieval seems to slow the rate of forgetting.
Forgetting functions (amount remembered as a function of time since an event was first experienced) have been extensively analyzed. The most recent evidence suggests that a power function provides the closest mathematical fit to the forgetting function. [http://psy.ucsd.edu/~jwixted/Reprints/Wickelgren%20Ebbinghaus%20(final)_formatted.pdf]
One of the first people to study the mechanisms of forgetting was the German psychologist
Hermann Ebbinghaus. Using himself as the sole subject in his experiment, he memorized lists of three letter nonsense syllable words—two consonants and one vowel in the middle. He then measured his own capacity to relearn a given list of words after a variety of given time period. He found that forgetting occurs in a systematic manner, beginning rapidly and then leveling off. Although his methods were primitive, his basic premises have held true today and have been reaffirmed by more methodologically sound methodsFact|date=March 2007.
Theories of forgetting
The four main theories of forgetting apparent in the study of psychology as follows;
Cue-dependent forgettingor retrieval failure, is the failure to recall a memorydue to missing stimuli or cues that were present at the time the memory was encoded. It is one of five cognitive psychologytheories of forgetting. It states that a memory is sometimes temporarily forgotten purely because it cannot be retrieved, but the proper cue can bring it to mind. A good metaphorfor this is searching for a book in a library without the reference number, title, author or even subject. The information still exists, but without these cues retrieval is unlikely. Furthermore, a good retrieval cue must be consistent with the original encoding of the information. If the sound of the word is emphasized during the encoding process, the cue that should be used should also put emphasis on the phoneticquality of the word.Information is available however, just not available without these cues.
Trace decay focuses on the problem of availability caused when memories decay. Hebb said that incoming information creates a pattern of neurons to create a neurological memory trace in the brain which would fade with time. Repeated firing causes a structural change in the synapses. Rehearsal of repeated firing maintains the memory in STM until a structural change is made.
Forgetting that occurs through physiological damage or dilapidation to the brain are referred to as organic causes of forgetting. These theories encompass the loss of information already retained in
long term memoryor the inability to encode new information again. Examples include Alzheimer's, Amnesia, Dementia, consolidation theory and the gradual slowing down of the central nervous system due to aging.
Interference theoryrefers to the idea that forgetting occurs because the recall of certain items interferes with the recall of other items. In nature, the interfering items are said to originate from an over stimulating environment. Interference theory exists in two branches, Retroactive and Proactive inhibition each referring in contrast to the other. Retroactive interference is when the past memory interferes with the later memory, causing it to change in a particular extent. On the other hand, proactive interference is when the later memory interferes with the older memory, causing it to change.
Decay theory states that when something new is learned, a neurochemical, physical "memory trace" is formed in the brain and over time this trace tends to disintegrate, unless it is occasionally used.
Definitions and controversy
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
amnesiacaused by an accident.
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 supposedly contradicted by the fact that one is able to ride a bike even after not having done so for decades. " Flashbulb memories" are another piece of seemingly contradicting evidence. It is believed that certain memories "trace decay" while others don'tFact|date=March 2007. Sleep is believed to play a key role in halting trace decayFact|date=March 2007, although the exact mechanism of this is unknown.
Experience curve effects
last = Wixted
first = J.
contribution = The psychology and neuroscience of forgetting.
year = 2004
title = Annual Review of Psychology
volume = 55
pages = 235-269
Wikimedia Foundation. 2010.