Transcript Forgetting slide show

FORGETTING
???
FORGETTING

Forgetting refers to the inability to retrieve
previously stored information.

When you forget something it means that it is
unavailable to you at the time you are trying to
remember it.

The information may be stored in your memory, but
for some reason you are unable to retrieve it.

Although forgetting results in the loss of information
and many skills, if you did not forget, your mind
would be cluttered with so much information that you
would have great difficulty retrieving and selecting
the information that you needed.

Like remembering forgetting has an adaptive
purpose and contributes to our survival and our
sanity.
THE FORGETTING CURVE

Hermann Ebbinghaus was a German psychologist
who was the first to scientifically study forgetting in
the late 1800’s.

To measure the amount of information retained and
the rate at which information is forgotten,
Ebbinghaus conducted an experiment using himself
as the only participant.

The experiment involved him learning a series of
lists of nonsense syllables, until he could recite them
without error on two separate occasions.

Ebbinghaus tested his recall for each list after a
specific period of time had elapsed from the initial
learning.

He first learned one list, then tested his recall after a
specific delay period. Then he learned another list,
tested his recall after another delay period, and so
on.

The delay ranged from 20 minutes to 31 days.

Ebbinghaus was then able to measure the amount
and rate of forgetting.

-
FINDINGS:
20 minutes after initial learning he could remember
58% of nonsense syllables.
One hour after learning his retention was 44%.
A day later he could recall 34%.
A week later his recall had fallen to around 21%.

This data, once plotted on a graph became known
as the forgetting curve.

The forgetting curve shows the pattern of
forgetting that occurs over time.



Generally the graph shows that forgetting is rapid
soon after the original learning, then the rate of
memory loss gradually declines, followed by stability
in the memories that remain.
More than half of the memory loss occurs in the first
hour of learning.
Virtually all the information that will be forgotten is
lost in the first eight hours.

This pattern of forgetting tends to occur for a range
of materials under many conditions.

The more meaningful the material, the slower the
rate of forgetting.

The amount and rate are also influenced by how
well the information was initially encoded- the better
the initial learning, the longer the material is likely to
be retained.
MEASURES OF RETENTION

What methods do we use to test what has been
retained in memory?

Teachers generally use tests or exams. But is
your performance on a test or exam a reliable
measure of how much information you have
retained in memory?

There are different types of questions teachers
ask, including multiple-choice questions,
true/false questions, fill-in-the-blanks, short
answer, and essay questions.

Research shows that the amount of information
that will be retrieved from memory is, at least
partly, dependent on the type of question asked.

There are three main kinds of measures that are
used to determine how much information has
been retained: recall, recognition and relearning.
RECALL

What are the names of the 7 dwarfs?

In order to answer this question, you would have
searched through your long-term memory, tried to
locate the information required, and either have
produced or not produced the correct information.
RECALL
 This
approach to measuring the amount of
information retained in memory is a test of
recall.
 Recall
involves being asked to reproduce
information with the fewest possible cues
to assist retrieval.

In an experiment used to measure recall as a
measure of retention, participants might be
required to learn a list of randomly selected
words. Then, after a period of time, they may be
required to write, in any order, as many of the
words off the list as they can.

This method is called free recall.

Free recall is involved when participants are only
asked to remember as much information as
possible, in no particular order.

If participants were asked to recall a list of words
in the order in which they were presented,
researchers would be asking for serial recall.

Sometimes the general cue we are provided
with to search information in our long-term
memory is too general and the list of possible
matches is too long.

Cued recall makes use of specific cues to aid
retrieval. For example; being given the first letter
of each of the 7 dwarfs names.
RECOGNITION
 Which
of the following are the names of
the 7 dwarfs?
-Bashful
-Happy
-Grumpy
-Pop
-Sleepy
-Goofy
-Dopey
-Sneezy
-Doc
-Grouchy
RECOGNITION

Recognition involves identifying the correct
information from among alternatives, such as in the
previous question.

Generally we can retrieve more information when
tested by the recognition method than we can with
the recall method because the recognition method
provides more cues that assist in the location and
retrieval of information from long-term memory.
 In
an exam situation, students typically
prefer M/C questions or true/false
questions to an essay or short answer
questions.
 M/C
and true/false questions involve
recognising the correct response from
among a small number of alternatives,
whereas essay question require recall,
where there are very few cues.
 The
-
-
difference between recall and
recognition is this:
In recall we ask What is the item?
In recognition we ask Is this the item?
RELEARNING

Most people have times when they are unable to
recall or to recognise information that has been
stored in long-term memory.

Even though they are unable to retrieve this
information, it does not necessarily mean that it
has been forgotten.

Relearning or the method of savings, involves
learning information again that has been
previously learned and stored in long-term
memory.
 Typically
relearning something takes less
time than it did to learn it originally.
 If information is learned more quickly the
second time it is assumed that there must
be some information retained from the first
learning experience, whether we realise it
or not.
HERMANN EBBINGHAUS

Ebbinghaus did an experiment using nonsense syllables
(eg. Jux, kuv). Nonsense syllables are often used in
memory research instead of words so that retention is
not affected by the words having some sort of meaning
or association with words already stored in memory.
When Ebbinghaus measured his memory for what he
had learned, he found that even if he could not
remember a single item from the original list, he could
relearn the list much quicker a second time than he had
been able to with the original list. This indicated that
some information had been retained from the initial
learning.
 This
is also called the method of savings
because it can be calculated using the
following formula.

Savings = (no. of trials for original learning) – (no. of trials for relearning) x 100
(no. of trials for original learning)
1
10 – 5 x 100 = 50%
10
1
Eg.
A
savings score can also be calculated on the
basis of the time taken to relearn information.
Savings = (time taken for original learning) – (time for relearning) x 100
(time for original learning)
1
RELATIVE SENSITIVITY OF
MEASURES OF RETENTION
 Recall,
recognition and relearning differ in
their relative sensitivity as measures of
retention. The sensitivity of a measure of
retention refers to its ability to assess the
amount of information that has been
stored in memory.
 Recall
tends to be the least sensitive
measure of retention, relearning tends to
be the most sensitive measure of
retention, and recognition tends to be less
sensitive than relearning but more
sensitive than recall.

In a study by Nelson (1978) on the three measures of
retention, 24 university students were used as
participants.
 The experiment consisted of three stages- the initial
learning stage, a stage in which recall and recognition
of the initial learning were tested and finally a
relearning stage.
 In the first stage, participants were given a series of
number-word pairs to learn, such as 49-party and 95horse.
 The second stage of the experiment required the
participants to participate in the testing and relearning
stages of the experiment.

In the testing stage, participants were required to
complete two different types of tests. The first was a test
of recall where the participants were given the original
number as a cue and were asked to provide the
association word that went with it. The second test was
similar but required the participants to name the
associated words from a list of 20-10 of which were the
original words and 10 of which were new, unrelated
words. The third stage of the experiment involved
relearning the words from the previous list which had
been incorrectly recalled and 10 new word pairs. They
were then given a recall test on both the new information
and the old information.
 The
results showed that a mean score of
48% of the target words were correctly
recalled, and 69% were correctly
recognised in the testing. Furthermore the
percentage of target words correctly
recalled during the relearning stage was
significantly higher for the old items (88%)
than for new items.
 These
results were found to be significant
at the p<0.001.
 What
does this mean?
v
THEORIES OF
FORGETTING
Psychologists have developed a number of
theories to explain why we forget.
Forgetting may occur because:
1. The right retrieval cue is not used
2. There is interference from competing
material
3. Memory fades through disuse over time
RETRIEVAL FAILURE THEORY

If you have ever experienced a ‘mental blank’ in an
exam or in a job interview, only to recall the exact
information at a later point in time, you have
experienced retrieval failure.

Most of the time we can retrieve information from
LTM with relative ease.

This is because most of the time you are able to
retrieve information from the various storage
systems in your LTM using a retrieval cue to locate
the relevant information.

A retrieval cue is any stimulus that assists the
process of locating and recovering information
stored in memory.

It is a prompt or cue to guide the search and
recovery process within memory.

According to retrieval failure theory we sometimes
forget because we lack or fail to use the right cues
to retrieve information stored in memory.

This explanation of forgetting suggests that
memories stored in LTM are not actually forgotten,
but are temporarily inaccessible.
Tip-of-the-tongue phenomenon
 One
of the most frequent experiences of
retrieval failure is the tip-of-the-tongue
phenomenon (TOT).
 Tip-of-the-tongue
is the feeling of being
aware of knowing something, being
confident that you will remember it at any
moment, but not being able to retrieve the
information at that point in time.
 When
we experience this it seems that
even though we can’t say the word, we do
have specific information about it eg. What
it starts with, how many syllables it has or
what it rhymes with.
 This suggests that the TOT phenomenon
involves partial retrieval in which bits of
information can act as retrieval cues.
 Brown
and McNeill (1966) demonstrated
the TOT phenomenon by asking
participants to memorise a list of words
that are generally not in everyone’s
vocabulary; for example sampan which is
a wooden Chinese fishing boat. The words
that participants came up with when trying
to recall the correct word sometimes
resembled the word in meaning
(‘junkboat’) but most often resembled it in
sound (‘sarong’).
 As
a result they believed that a word is
stored in a specific location that contains
information about its sound and its
meaning. Therefore we can retrieve words
according to either characteristic. These
words are also linked to other similar
words through memory pathways which is
often why we are able to retrieve similar
words in place of the one we really want.
 They concluded that phonetic and
semantic features are needed in the
retrieval of a word.
INTERFERENCE THEORY




Recall can become difficult when we are trying to
remember a lot of similar information. This is partly
because similar memories interfere with the retrieval
of one another.
This highlights a second reason for forgetting- that
memories can interfere with one another.
Interference theory proposes that forgetting in LTM
occurs because other memories interfere with the
retrieval of what we are trying to recall, particularly if
the other memories are similar.
If learning of similar material occurs close in time,
interference is more likely.

There are two types of interference:
1.
Retroactive interference
2.
Proactive interference
RETROACTIVE INTERFERENCE

When new information interferes with the ability to
remember old information, psychologists refer to the
interference as retroactive interference.

Eg. You are at a party and you are introduced to a
guy named John. Not long after you are introduced
to Jim. After a while you bump into John again but
accidentally call him Jim.

With retroactive interference, new learning interferes
with the retrieval of previously learned material.
PROACTIVE INTERFERENCE

Interference also works in the opposite direction.

Information learned previously can interfere with our
ability to remember new information. This effect is
called proactive interference.

According to interference theory, interference
primarily comes from memories of similar
information.
MOTIVATED FORGETTING




Motivated forgetting refers to the inability to
retrieve information because the individual derives
some benefit from not remembering.
Sigmund Freud was one of the first to consider the
idea of motivated forgetting, which he called
repression.
Repression involves unconsciously blocking a
memory of an event or experience from entering
conscious awareness.
He claimed that it was an unconscious, unintentional
process through which the individual may avoid
feelings of anxiety about traumatic events.
An important feature of repressed memories is that
although they may not be readily accessible to
conscious recollection, they may still be retained.
Eg. Hypnosis


Memories that are retrieved from the unconscious
are called recovered memories.
 Not
all motivated forgetting is
unconscious- an individual may quite
intentionally and consciously want to
forget something.
 This is called suppression.
 Suppression involves being motivated to
forget an event or experience by making a
deliberate conscious effort to keep it out of
conscious awareness.
 The person knows that the memory is
there, however they choose not to think
about it.
 Brain
imaging techniques show that when
a person is trying to suppress a memory
the left and right frontal lobes are more
active and there is less activity is the
hippocampus where information is usually
recalled.
 Many psychologists accept that memory
can be affected by an individual’s
conscious or unconscious needs, fears,
anxieties, and desires.
DECAY THEORY

Some psychologists suggest that forgetting is a
process of decay.

Memories that are formed and not used begin to
fade, become weaker with time, and eventually
decay to the point where they can no longer be
recollected- that is, they are forgotten.

This theory, known as decay theory, was first
proposed by Edward Thorndike in 1914.

Decay theory explains forgetting based on the
assumption that when something new is learned, a
memory trace or neural imprint of the experience
that contains the stored information is formed in the
brain; the trace gradually fades over time through
disuse unless it is reactivated by being used.

Decay theory suggests that memories that are not
retrieved or rehearsed dissipate over time as the
synaptic connections between neurons that
constitute the memory trace begin to degrade.
 Forgetting
seems to be a combination of
the fading of memory traces, interference,
or the use of an inappropriate retrieval
cue.
Manipulation and
improvement of memory
 Research
findings indicate that much of
what we recall from long term memory is
not an accurate representation of what
actually happened previously.
 Instead, it is a logical account of what
might have happened, shaped by our
thoughts, attitudes and beliefs and by who
we are as individuals.
 The details of human memory can change
over time.
 Confidence in memory is no guarantee
that it happened.
 How
do distortions creep into our
memories?
 A new memory is not a recording, it is
actively reconstructed.
 To form a new memory you actively
organise and encode different types of
information: visual, auditory, tactile etc.
 When you later try to retrieve this memory
you have to reconstruct the details of the
memory.
 In this process various factors can create
errors.
Manipulation of memory
 Frederick
Bartlett’s (1932) study on the
reconstructive nature of memory pg 393.
 Elizabeth Loftus also studied this in
regards to eye witness testimony.
 She found that eyewitnesses
reconstructed their testimony and
therefore it was not always accurate.
 Most
of her studies typically involved
showing participants a short film, video or
slides of a car accident.
 Participants were then asked specific
questions about the scene they
‘witnessed’.
 Sometimes, information that was not
present in the actual scene or which
contradicts the scene is introduced.
 At other times leading questions are
asked.
 Loftus’
research makes it clear that
leading questions can be used to
manipulate memory.
 A leading question is a question that has
content or is phrased in such a way as to
suggest what answer is desired or to lead
to the desired answer.
 These kinds of questions can implant
memories into a witnesses memory and
falsely produce the things that they think
they recall.
Studies by Elizabeth Loftus
 Flow
chart on the two experiments pg 394.
Studies by Elizabeth Loftus
 Although
eyewitnesses may think, feel and
behave differently when observing a crime
in the laboratory as compared with realworld settings, eyewitness testimony
cannot be regarded as faultless, even
when the witness is trying to be truthful.
 Loftus suggests that whenever we retrieve
a memory it does not actually represent
the original memory but a reconstruction of
what we actually stored.
IMPROVEMENT OF MEMORY

We can rely on specific mental strategies if we want
to improve our memory.

Sometimes we are able to remember information
simply because it stands out or is unusual.

Other information requires conscious effort in order
for it to be remembered.

To ensure that information goes beyond sensory
memory we must pay attention to it. It must also be
organised and integrated into LTM with information
already in LTM.
CONTEXT- AND STATEDEPENDENT CUES

Another effective way of enhancing retrieval from
LTM is to re-create the conditions under which the
required information was originally learned.

This approach is based on the encoding specificity
principle.

This principle involves a general ‘rule’ that the more
closely the retrieval cues match the original learning
conditions, the more likely it is that the information
will be recalled.
CONTEXT-DEPENDENT CUES

Why is it that police investigating a crime may take
an eyewitness back to the crime scene, particularly
if the witness is having some trouble recalling some
of the details of what they saw which are critical to
the investigation?

The answer is based on research findings that cues
in the environment may be important in helping to
locate and retrieve related memories.

Context-dependent cues are environmental cues
in the specific context (setting) where a memory was
formed, which act as retrieval cues to help access
the memories formed in that context.

These cues may include the sights, sounds and
smells within the specific situation.

The context dependency of certain memories helps
explain why an eyewitness may recall apparently
forgotten information about a crime when they return
to the scene of the crime.
STATE-DEPENDENT CUES

State-dependent cues are associated with an
individual’s internal physiological and/or psychological
state at the time the memory was formed, which act as
retrieval cues to help access those memories.

It seems that taking a drug can produce an internal state
with unique psychological and physiological
characteristics, aspects of which may become encoded
with new memories.

At a later point, the same internal state can provide
additional retrieval cues that assist recovery of
information from memory.

Your mood also provides state-dependent cues.

We seem to associate good or bad events with their
accompanying emotional state.

This means that our emotional state becomes a
retrieval cue when we feel good or bad again, and
they trigger memories that are consistent with the
mood.

However, when we are happy, happy events are
recalled; but when we feel down, our minds can
become flooded with sad or negative events of the
past which in turn darken our interpretations of
current events.
MNEMONIC DEVICES

Techniques for enhancing or improving memory are
known as mnemonic devices.

A mnemonic device is any internal strategy or
method that makes it easier to encode, store or
retrieve information.

Mnemonic devices may be visual or verbal, and they
generally impose some sort of organisation on the
material to be remembered.






Mnemonic strategies are always entirely internal.
Memory aids such as writing a shopping list are not
mnemonic strategies because they rely on external
items (in this case a pen and paper).
Acronyms
Acrostics
Peg word method
Narrative chaining
Method of loci
Acronyms
 Acronyms
involve using the first letter of
each word to be remembered to create a
pronounceable word or name. E.g.
Sudden Infant Death Syndrome has
become the acronym SIDS.
 The letters of the abbreviation act as a
retrieval cue. They are essentially a type
of chunking.
 The abbreviation must be pronounceable.
Acrostics
 Acrostics
involve constructing a phrase or
sentence from words that begin with the
first letter of each word of the information
to be recalled.
 E.g. E, G, B, D, F are the names of the
notes on the lines of the staff otherwise
known as ‘Every Good Boy Deserves
Fruit’.
 Acrostics can be useful when trying to
remember information in a sequence.
Peg-word method
 The
peg-word method uses an easily
remembered rhyme to visually associate
items to be remembered.
 E.g. pg 405.
 When recalling the information you recite
the rhyme and the words that are
associated with each line can be recalled.
 This method is more effective when the
rhyming word and the item to be
remembered can be linked.
 This
is generally a two step process:
1. Memorise key words that can be
associated with numbers (one-bun)
2. Create an image of the items you need to
remember with key words.
E.g.
Your shopping list
One – bun
must include:
-Toothpaste
Two – shoe
-Oranges
Three – tree
-Ham
-Yoghurt
Four – saw
-Eggs
Five – hive
NARRATIVE CHAINING
Narrative chaining links unrelated items to create a
story-like sequence of events.
 Construct a story that involves the following
items in the order in which they appear here:
Sunscreen, cereal, soup, chocolate, butter, English
muffins.
 For example in a study using this method
participants showed that on average those who
used narrative chaining remembered 93% of words
learnt and those who used no method remembered
only 13%.

METHOD OF LOCI

The method of loci is a mnemonic that relies on the
use of a well-learned pathway with distinct locations
that can be associated with the items to be
remembered.

To use the method of loci, you need to recall a
sequence of distinct locations and associate them
with each word to be remembered.

Imagine yourself walking through a house and
associate each word on a list with an item in each
room.

When you need to recall a list of words, imagine
yourself revisiting the house and walking through
the same rooms-this will probably cause you to
remember the word you associated with each
location.

Experimental investigation of the method of loci has
found that participants more than doubled the
number of words they were able to recall when
using the method of loci, compared to when relying
on free recall.