Theories of Forgetting

Memory lost to the passage of time

Peterson & Peterson 1959 found that memory
held in STM was lost after approximately 18
seconds due to trace decay

Hebb 1949 - a brief and fragile memory trace is
laid down and without rehearsal that memory
is lost. Rehearsal is repeated neural activity which
allows memory to be transferred a the Long
Term Memory Stiore

Limited number of space/slots in Short Term Memory (7 +/- 2)
so old information is displaced.

Brown-Peterson technique: last few words on list displaced by counting task.

Warrington & Sahllice 1972 Study of KF found that in Short Term Memory audio letters/digits were more easily forgotten than visual stimuli. This suggests Short Term Memory has miltiple stores.

The less attention focused on information, the more likely it is to be forgotten.

Rugby Players. Long Term Memory

Natural experiment on decay and interference

Decay theory assumed that the passage of time would not affect the recollection of information

However, results were varied, therefore can conclude that intervening memories interrupted encoding in Long Term Memory and interference has greater impact on decay than the passage of time

Context-Dependant Forgetting

These studies showed that it is easier to recall information within the same context in which it was learned (e.g. students perform better on tests when they are conducted by the same teacher who taught them the material and in the same room in which that material was learnt.)

Also remembering information is made easier with retrieval cues

State-Dependant Forgetting / The effects of alcohol on recall

Found that it is more likely to remember information if you are in the same emotional or physical state when learning it

Context-Dependant Forgetting

Study involved divers and the effects of recall when learning and recall environment are the same?different

Results concluded that retrieval of information was best when learning and recall environments were the same

Alzheimer's

Dementia

Huntington's Disease

Parkinson's Disease

Schizophrenia

This decay happens due to disuse. Knowledge and skills fade.

A period of firmly making the memory stronger is necessary for recording memory into Long Term Memory

An injury to the head may prevent consolidation

This is when new information interferes with the recall of old information

Various studies from the 60's concerned a paired association technique. Results found participants were more likely to remember the associated word from the other list rather than the prompt word to begin with.

This is when old information interferes with the recall of new information

e.g. a moved cutlery drawer in a kitchen

Brain Damage

Related Studies

Brewin & Andrews, 2000
Study supports 'intentional forgetting'

Myers & Brewin, 1994
Study suggests is more likely to be a result of a troubled childhood

Psychodynamic theory

Defence Mechanism

Develops from a fixation in childhood to reduce anxiety in adulthood

Is unconscious (the ego blocks the retireval of memories)