Forgetting and Remembering

Remembering
and
Forgetting
Mary Queen T. Bernardo

OUTLINE
 Organization of Memories
 Forgetting Curves
 Reasons for Forgetting
 Biological Bases of Memory
 Mnemonics: Memorizations Methods
 Cultural Diversity: Aborigines Versus White Australians
 Research Focus; False Memories
 Application: Eyewitness Testimony

ORGANIZATION OF MEMORIES
 Network Theory
 We store related ideas in separate categories or files called
nodes.
 As we make associations among information, we create links
among thousands of nodes
 Cognitive map (Donald Norman)
 Personal associations that are followed in order to remember
something

FORGETTING CURVES
 The earliest that people in different cultures can recall
personal memories averages 3 ½ years old (Q. Wang,
2003).
 Researchers did find that children as young as 13 months
can recall visual event, such as a sequence of moving toys.
 Cognitive map (Donald Norman)
 Personal associations that are followed in order to remember
something

 Forgetting
Curve/Law-
Ebbinghaus
forgetting curve
over 30 days--
initially rapid,
then levels off
with time
12345 10 15 20 25 30
10
20
30
40
50
60
0
Time in days since learning list
Percentage of
list retained
when
relearning

Forgetting Curve
<<rem Ebbinghaus gave us this>>
 The forgetting curve for Spanish learned in school
Retention
drops,
then levels off
1 3 5 9½ 14½ 25 35½ 49½
Time in years after completion of Spanish course
100%
90
80
70
60
50
40
30
20
10
0
Percentage of
original
vocabulary
retained

Why we rarely
remember
personal
events before
age 3 ½?
1. Children have little or
no language skills
(Sicock & Hayne,
2002)
2. Children have not yet
developed a complete
memory circuit in the
brain (Bauer, 2002).

Remembering
 Network Hierarchy
 Arrangement of nodes in a certain order
 Top- Abstract information
 Animal
 Middle- More specific information
 Bird or fish
 Bottom- concrete information
 Blue jay, rooster, shark or guppy

REASONS FOR FORGETTING
 Repression
 Poor Retrieval Cues/Retrieval Failure
 Amnesia
 Interference

Info enters the sensory
memory where we have to
pay attention to it or it is
lost
It moves into STM/working
memory where there is
limited capacity and
duration. To increase
capacity we can chunk info.
To increase duration we can
rehearse info
We must then move
this info into LTM by
connecting it to stuff we
already know,
encoding.

Forgetting from Short-Term Memory:
Decay or Displacement?
ST
M
LT
M
After information enters STM, a copy may or may not be sent to
LTM.
Soon, however, that information will disappear from STM.
Two processes could cause information to disappear from STM:
decay and displacement.

ST
M
LT
M
Decay: information that is not rehearsed disappears as time passes.
Displacement: information being held in STM is pushed out by newly
arriving information.
Displacement is most likely to occur when the capacity limit of STM
has been reached (about 7 units of information).

ST
M
LT
M
Displacement is most likely to occur when the capacity limit of STM
has been reached (about 7 units of information).
R D Q L T H JB

Decay Theory of Forgetting
100%
Rehearsal
Day 1 Day 2 Day 7 Day 30
• Example: reviewing notes after class
Amountofinformation
• Memory fades away with time
• unless there is rehearsal

Poor Retrieval Cues/Poor Encoding
 Retrieval cues are mental reminders that we create by
forming vivid mental images or creating associations
between new information and information we already know.

Motivated Forgetting
One explanation is REPRESSION:
 in psychoanalytic theory, the basic
defense mechanism that banishes
anxiety-arousing thoughts, feelings and
memories from consciousness.
Emotional process that automatically
hides emotionally threatening or
anxiety-producing information in the
unconscious
Sexual abuse

Retrieval Failure
 The memory was encoded and stored, but
sometimes you just cannot access the memory.

Retrieval Failure
 Forgetting can result from failure to retrieve information from long-term memory
External
events
Attention
Encoding
Encoding
Retrieval failure
leads to forgetting
Retrieval
Sensory
memory
Short-term
memory
Long-term
memory
 The memory was encoded and stored, but sometimes you just cannot access the
memory.

DECAY THEORY
Memories fade away or decay gradually if unused
Research, however, has demonstrated that even
memories which have not been rehearsed or
remembered are remarkably stable in long-term
memory.

Factors Influencing Retrieval
 Serial position effect
 The tendency to remember the beginning and ending
items of a sequence or list better than the middle items
 Primacy effect
 The tendency to recall the first items on a list more
readily than the middle items
 Recency effect
 The tendency to recall the last items on a list more
readily than the middle items

Factors Influencing Retrieval
 Environmental context and memory
 any elements of the physical setting in which a person
learns information are encoded along with the information
and become part of the memory trace
 Memories are better recalled in the environment they
were learned

Encoding Failure
 Information may never be encoded into LTM
EncodingX Long-term
memory
Encoding failure
leads to forgetting
Short-term
memory

 Information never enters the long-term memory
 Age effects: As age inc, encoding dec – Brain less responsive w/ age
External
events
Sensory
memory
Short-
term
memory
Long-
term
memory
Attention
Encoding
Encoding
Encoding
failure leads
to forgetting
Encoding Failure

Examples of Encoding Failure
What letters accompany the number 5
on your mobile phone?
Where is the key “y” in a computer
keyboard?

Amnesia
 Organic Amnesia
 Physical trauma to brain
structure.
 Anterograde: Can’t recall event
after injury
 Retrograde: Can’t recall events
that occurred before
Loss of memory that may occur after a blow or damage to the brain, or after
disease, general anesthesia, certain drugs, or severe psychological trauma
 Functional Amnesia
 Due to psychological trauma
 Psychogenic amnesia
 Dissociative Fugue: Forget
“selves” for a time…identity,
life, etc

 Infantile Amnesia
 Remember very little
about 1st
years of life
 Why?
 Structure
 Language
 Memories:
 3/4th
birthday
 Narrative 7yrs

 Proactive: Old info interferes
with new learning
 Retroactive: New info makes
people forget old info
INTERFERENCE
 People forget info because other learned info interferes.

Interference
Retroactive: New info
makes people
forget old info
Proactive: Old info
interferes with new
learning

Proactive Interference
EXAMPLES:
If you call your new girlfriend your old
girlfriend’s name.
Memories of where you have seen a friend last week
interfere your ability to remember where you saw him
today.

Example: When new phone number
interferes with ability to remember old
phone number
Retroactive Interference
.

Forgetting
 Distortion
 Caused by bias or suggestibility

 Amnesia
 Loss of memory that may occur after a blow or damage to the
brain, or after disease, general anesthesia, certain drugs, or
severe psychological trauma
 Distortion
 Caused by bias or suggestibility

Random Retrieval Phenomena
 Tip of the Tongue
 Try to retrieve familiar
piece of info but can’t
quite do it
 Blocking Theory
 Partial Activation

Random Retrieval Phenomenon
 “I Froze”
 Stress hormones inhibit
hippocampus
 Cognitive function and
LTM retrieval fail

 Priming-
 Preparing networks to remember...
 Hte plpae si edr
 Grandma is buying an apple.
 Hte plpae si edr.
 The apple is red

 Déjà vu
 “Seen before”
 Current event provokes similar
retrieval cues, but you haven’t
done it.
 Jamais Vu
 “Never before”
 Event doesn’t match earlier
encoded clues, but know
you’ve done it

MNEMONICS (new-MON-ick)
 are ways to improve encoding and create better
retrieval cues by forming vivid associations or
images which improve recall
Two Common Methods
1. Method of Loci (LOW-sigh)
- an encoding technique that creates visual
associations between already memorized places and
new items to be meorized.

2. Peg Method
 - an encoding technique that creates associations
between number-word rhymes and items to be
memorized.
Example: One is a bun
Two is a shoe

CULTURAL DIVERSITY
 Survival in the aboriginal culture depends on
encoding and remembering visual information, while
surviving in an industrial culture depends on encoding
and remembering verbal (written0 information.
 This cultural difference predicts that people would
perform differently on tests, depending on whether
the test s emphasized visual or verbal retrieval clues.

FALSE MEMORIES
 condition in which a person’s identity and relationships center around
a false but strongly believed memory of traumatic experience
 sometimes induced by well-meaning therapists

False Memories
 Lest you be overconfident:
“In a 1992 op-ed piece for the New York Times, Garry Trudeau recollected some of his
experiences related to the draft for the Vietnam War. Trudeau remembered receiving calls of
concern from friends and family on the night of the draft lottery, after they had heard about his low
number. He then recalled a series of events involving his attempts to gain a draft deferment:
requesting a national security deferment from the draft board for his work with a magazine;
deciding not to apply for conscientious objector status because he could imagine circumstances in
which he would take another’s life; preparing for his interview with the draft board by receiving a
“memorable haircut”; and finally, gaining a medical deferment from the board after sending them,
upon his physician father’s advice, X-rays revealing a past ulcer. This recollection, he reported,
remained unchanged for 20 years.
However, after talking to others and examining the records of his draft correspondence,
Trudeau uncovered some notable discrepancies between his recollection and what actually
happened. No family member or friend remembers making a call of concern. Trudeau now
believes he imagined their concerns, because the act ov examining this recollection led him to
remember that he was in fact out having a few beers that night. He discovered that he actually
applied for an occupational deferment and, upon reflection, wonders how he could have believed
that working for a “glorified travel magazine” was justification for a national security deferment. He
also neer received a “memorable haircut”, not did he apply for conscientious objector status in part
because of the prohibitive paperwork” (Dodson & Schacter)

ST
M
LT
M
The original version of the Atkinson-Shiffrin model emphasized decay
as the main cause of forgetting in STM. Their later version
emphasized displacement. Here is a study that compared decay to
displacement and showed a much greater effect of displacement.
B R D Q L T H
J

ST
M
LT
M
The Probe-Digit Procedure
You are read a list of 16 digits:
(Waugh & Norman, 1965)
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8
After the last digit, you hear a tone...
TONE

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8The tone is a signal to recall one of the digits. The last digit before the
tone (8) occurs only once at an earlier point in the list.
TONE
This is called the “probe”.
Probe

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8
Which is more important in causing forgetting, time or the additional
digits?
TONE
Probe
4
Recall
The decay principle implies time; the displacement principle implies
digits.

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8
Time and digits are correlated (confounded). To separate them,
Waugh & Norman used two rates of presentation: slow (1 digit per
second) and fast (4 digits per second).
TONE
Probe
4
Recall
+1+ 1 +1 +1 + 1 +1+ 1+ 1+ 1+ 1 +1 +1 = 12
Slow Presentation (Seconds)

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8More time passes between the digit and the tone with slow presentation (12
seconds) than with fast presentation (3 seconds). According to the decay
principle, the chances of recalling the digit should be lower with slow than with
fast presentation.
TONE
Probe
4
Fast Presentation (Seconds)
1 + 1 + 1 = 3

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8According to the displacement principle, the chances of recalling the digit
should be the same with fast and slow presentation because the number of
digits before the tone is the same in both conditions.
TONE
Probe
4
1 + 1 + 1 = 3

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8Waugh & Norman made this comparison with the probe digit in each of the
following positions: 3 (shown here), 5, 7, 9, 10, 12, 13, or 14.
TONE
Probe
4
1 + 1 + 1 = 3
Both decay and displacement predict an increase in recall as the probe gets
closer to the tone.

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8
There was slightly (but not significantly) higher recall with fast than with slow
presentation when the probe was near the beginning of the list. Recall
dropped sharply as the probe was moved from the end toward the beginning.
TONE
Probe
4
1 + 1 + 1 = 3
Results

ST
M
LT
M
7 0 8 4 1 6 0 9 5 5 3 7 2 4
7 8
As time passes, what mainly causes forgetting from short-term
memory is exposure to additional information, not the passage of
time.
TONE
Probe
4
1 + 1 + 1 = 3
Conclusion

Forgetting and Remembering

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