Why we forget
3 experiments
5 ways to forget
objectives
• Compare and contrast Ebbinghaus, Linton’s
Memory experiments
• TRACE (LIST IN STEPS) the 5 mechanisms that
account for forgetting
chapter 8
Forgetting curve
Herman Ebbinghaus
tested his own memory
for nonsense syllables.
Forgetting was rapid at
first and then tapered off.
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
chapter 8
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.
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.
2.
3.
4.
5.
Decay
Replacement
Interference
Cue dependent
Repression
chapter 8
Decay theory
The theory that information in memory eventually
disappears if it is not accessed
Applies more to short-term than long-term memory
chapter 8
Replacement
The theory that new information entering memory can wipe
out old information
In 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.
chapter 8
Interference
Similar 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
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
chapter 8
Cue-dependent forgetting
The inability to retrieve information stored in
memory because of insufficient cues for recall
Physical state can be a memory cue
State-dependent memory: the tendency to remember something
when the rememberer is in the same physical or mental state as
during the original learning
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
chapter 8
Amnesia
The partial or complete loss of memory for
important personal information
Psychogenic 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
chapter 8
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.
Summary
• 3 experiments
• 5 forgetting factors