Why we forget

3 experiments5 ways to forget

objectives

• Compare and contrast Ebbinghaus, Linton’s Memory experiments

• TRACE (LIST IN STEPS) the 5 mechanisms that account for forgetting

Forgetting curveHerman Ebbinghaus tested his own memory for nonsense syllables.

Forgetting was rapid at first and then tapered off.

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Study of Memory

• Memories weaken over time• Hermann Ebbinghaus- Experiment with

memory• Learned nonsense syllables (POV,KEB)• Then tested his recall over time• Found that there is a rapid initial loss of

memory, followed by a declining rate of loss

Linton’s forgetting curve

In contrast to Ebbinghaus, Linton’s memory for personal events was retained over a period of several years and then decreased rapidly.

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Marigold Linton

• Like ebbinghaus used self as subject • Used years not days• Every day for 12 years, recoded on 4x6 cards at least 2

things that happened that day• I had diner at the red lobster had delicious cheese

biscuits• I land in Paris, France • Once a month she took random sampling of the cards

and tested memory of events and dates• Not as rapid as ebbinghaus why?

5 concepts to forgetting….

1. Decay 2. Replacement3. Interference4. Cue dependent 5. Repression

Decay theoryThe theory that information in memory eventually disappears if it is not accessed

Applies more to short-term than long-term memory

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ReplacementThe theory that new information entering memory can wipe out old informationIn one study, researchers showed subjects slides of a traffic accident.The experimental group was misled into thinking there was a stop sign instead of a yield sign.

Even after being debriefed on the purpose of the study, subjects insisted that they really saw the stop sign.

The new information which came from the researchers replaced what the subjects saw.

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InterferenceSimilar items interfere with one another.Retroactive interference: forgetting that occurs when recently learned material interferes with the ability to remember similar material stored previously

Proactive interference: forgetting that occurs when previously stored material interferes with the ability to remember similar, more recently learned material

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Interference- #3 mechanism- Forgetting

• Occurs when learning 2 conflicting things in succession

• Example: French class followed by Spanish class.

• Info has encountered interference.• Interference theory 2 main categories

2 forms of interference or Blocking

• Proactive Interference- Old memory disrupts learning of New information

• PREVIOUS INFORMATION• For example: Move into a new home, then look for

items in old places• Retroactive Interference- Opposite of P.I. New info gets

in the way of old info• RECENT INFORMATION• For Example- Drive auto. Car, then forget to shift when

you drive manual car

Cue-dependent forgetting

The inability to retrieve information stored in memory because of insufficient cues for recall

Physical state can be a memory cueState-dependent memory: the tendency to remember something when the rememberer is in the same physical or mental state as during the original learning

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C.D.F.- 4

• Retrieval cue- item that can help find specific information

• Looking for last name of actor?• Find first name or recent movie they were in• If lack then maybe last in minds library• Willem Wagenaar- (1986)-Like Linton, Ebb.• Recorded events, 1 yr later forgot 20%, 5 yr 60%• BUT when gathered cues from witnesses, from 10 events

he FORGOT; he was able to recall something about all 10

Environment important in remembering

• Cues present when you learned new fact so could help be R.C. later

• Remembering easier when in same physical environment• Cues from the present match those from the past=overlap helps us

remember But also Explains déjà vu • Déjà vu- The false sense we have all had of being in the exact same

situation before as we are in right now• Means already seen in French• Some element in present situation , familiar from some other

context you can’t identify; even a novel, dream or movie, may make entire situation seem so familiar that it feels like it happened before

Mental state matters as well (bio)

• State dependent memory- tendency to remember something when the rememberer is in the same physical or mental state as during the original learning experience

• Police talk to victims of violent crimes soon• longer time= different emotions, Emotional state• Better retrieve memories when in same state= happy

memories when happy, or depressed {trap} • Key is think happy thoughts, break out of depression $$

$

Repression Controversy #5

• Amnesia- the partial or complete loss of memory for important personal information

Clues from the Tragic case of H.M.

• H.M. lost ability to form Declarative memories because of botched brain surgery

• Can remember events prior to surgery BUT New experiences slip away

• Anterograde amnesia- Transfer from STM to LTM severely impaired

• H.M. never been able to recognize people who take care of him, moon landing, computer age

Memories bio- Neurons, Synapses

• Long term memories form synapses transfer chemically into permanent synaptic changes

• Explains why blow to head or electric shock can cause loss of recent memories

• Retrograde Amnesia- loss of prior memory traces

AmnesiaThe partial or complete loss of memory for important personal informationPsychogenic amnesia: the causes of forgetting are psychological, such as the need to escape feelings of embarrassment, guilt, shame, disappointment

Traumatic amnesia: the forgetting of specific traumatic events, sometimes for many years

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The repression controversy

Repression: in psychoanalytic theory, the selective, involuntary pushing of threatening or upsetting information into the unconscious

Individuals are more likely to struggle with forgetting traumatic events.

It is hard to distinguish repression from other forms of forgetting.

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Summary

• 3 experiments• 5 forgetting factors