Download Memories - Forensic Consultation

CHAPTER 7
MEMORY
1
Defining Memory
• Memory is the persistence of learning over
time through the storage and retrieval of
information.
• Flashbulb memories are clear memories of
emotionally significant moments or events
and thus differ from other memories in their
striking clarity.
2
Atkinson-Schiffrin
• In some ways, our memory is like a computer’s
information-processing system.
• Information must be encoded, stored, and
retrieved.
• The Atkinson-Shiffrin three-stage processing
model states that we first record to-be-remembered
information as a fleeting sensory memory, from
which it is processed into a short-term memory
bin, where we encode it through rehearsal for
long-term memory and later retrieval.
3
• Contemporary memory researchers note that
we sometimes bypass the first two stages
and register some information automatically.
• They also prefer the term working memory
to short-term memory because it
emphasizes a more active role in the second
processing stage where we rehearse
information and associate new stimuli with
existing memories.
4
• The working-memory model includes
visual-spatial and auditory subsystems,
coordinated by a central executive processor
that focuses attention where needed.
5
Diagram of Three-Stage Memory
Model
6
Effortful Processing with
Automatic Processing
• Automatic processing occurs unconsciously;
• Effortful processing requires attention and effort.
• For example, our memory of a new telephone
number will disappear unless we work to maintain
it in consciousness.
• The next-in-line effect is our tendency to forget
what the person ahead of us in line has said
because we are focusing on what we will say in our
upcoming turn to speak.
7
Effortful Processing with
Automatic Processing
• The spacing effect is our tendency to retain
information more easily if we practice it
repeatedly than if we practice it in one long
session.
• The serial position effect is our tendency to
remember the last and first items in a long
list (for example, a grocery list) better than
the middle items.
8
Encoding in Remembering
Verbal Information
• When processing verbal information for
storage, we usually encode its meaning.
• For example, we associate it with what we
already know or imagine.
• Research indicates that semantic encoding
(of meaning) yields better memory of verbal
information than acoustic encoding (of
sound) or visual encoding (of an image).
9
Encoding in Remembering
Verbal Information
• This research also highlights the futility of
trying to remember words we do not
understand and the benefits of rephrasing
what we read and hear into meaningful
terms.
• The self-reference effect suggests that by
making information “relevant to me,” we
process it more deeply, and the information
will remain more easily accessible.
10
Encoding Imagery Aids
• In a variety of experiments, researchers have
documented the benefits of mental imagery.
• For example, we remember words that lend
themselves to picture images better than we
remember abstract, low-imagery words.
• We remember concrete nouns better than abstract
nouns because, for example, we can associate both
an image and a meaning with tiger but only a
meaning with process.
11
Encoding Imagery Aids
• Imagery is at the heart of many memory
aids, or mnemonics.
• For example, in the “method of loci,”
speakers remember their main points by
associating them with a familiar series of
locations such as the rooms and objects in
their house.
12
Chunking and Hierarchies in
Effortful Processing
• When we organize information into
meaningful units, we recall it more easily.
• In chunking, we cluster information into
familiar, manageable units, such as words
into sentences.
13
Chunking and Hierarchies in
Effortful Processing
• Chunking occurs so naturally that we often
take it for granted.
• When people develop expertise in an area,
they often process information in
hierarchies composed of a few broad
concepts divided and subdivided into lesser
concepts and facts.
• In this way, experts can retrieve information
efficiently.
14
Two Types of Sensory Memory
• Information first enters the memory system
through the senses.
• Iconic memory is a momentary sensory memory
of visual stimuli, a photographic or pictureimage memory lasting less than a second.
• Echoic memory is a momentary sensory
memory of auditory stimuli. Even if attention is
elsewhere, sounds and words can still be recalled
within three or four seconds.
15
Short-Term Memory
• Our short-term memory span for
information just presented is very limited—a
seconds-long retention of up to about seven
items, depending on the information and
how it is presented.
• Short-term recall is better for digits than
for letters, and better for what we hear than
what we see.
16
Long-Term Memory
• Although we know that our capacity for
storing information permanently is
essentially unlimited, we are not sure how
and where we store it.
• Research has shown that memories do not
reside in a single place and the so-called
memory trace is difficult to find.
17
Long-Term Memory
• Semantic encoding produced much better
memory than visual or acoustical encoding.
• Several reasons have been offered for the
self-reference effect. Perhaps the most
popular interpretation is that self-referencing
produces a more elaborate memory trace
than semantic encoding, the self being one
of the most highly elaborated structures in
memory.
18
Long-Term Memory
• Organization, not elaboration, explains the selfreference effect.
• That is, self-referencing instructions lead people to
organize the words on the list. Less organization is
imposed when people are simply asked whether a
word fits the meaning of a sentence.
• Self-referent and semantic encodings produce
virtually identical free-recall levels if they are first
equated for the amount of organization they
encourage.
19
Episodic, Semantic, & Procedural Memory
• Schacter was aware that laboratory evidence
pointed to three different memory systems:
– episodic memory, which allows us to recall
specific incidents from our pasts;
– semantic memory, which is the large network
of associations and concepts that underlies our
general knowledge of the world; and
– procedural memory, which enables us to learn
skills.
20
Episodic, Semantic, & Procedural Memory
• A golfer would need episodic memory to
remember where he hit the ball and how
many strokes he took.
• He would need semantic memory to know
the meaning of words like par, birdie, and
wedge, as well as the game’s strategies and
rules.
• He would need procedural memory to
remember how to drive and putt.
21
The Key-Word Method
• In the keyword method you think of a word
that sounds like all or part of the word to be
remembered.
• Then you create a scenario involving the
associated word and the definition of the
word-to-be-remembered.
• The keyword method has often been applied to foreign
vocabulary learning. In learning Spanish words, for
example, pato might first be recoded as an acoustically
similar keyword, pot. Then pot is linked to the word’s
meaning, duck, by means of an interactive mental image
involving a duck with a pot on its head.
22
Synaptic Changes Impacting Memory
Formation and Storage.
• Drugs that block LTP interfere with
learning.
• Scientists are developing drugs that boost
the production of the protein CREB or the
neurotransmitter glutamate, which seem
to build synaptic connections and enhance
long-term memory.
23
How Stress Hormones Can Affect
Memory
• The naturally stimulating hormones that
humans and animals produce when excited
or stressed make more glucose energy
available to fuel brain activity, signaling the
brain that something important has
happened.
24
How Stress Hormones Can Affect
Memory
• The amygdala, an emotion-processing
structure in the brain’s limbic system,
arouses brain areas that process emotion.
• These emotion-triggered hormonal
changes boost learning and retention.
• Emotionless events mean weaker
memories.
25
Deju Vu
• The déjà vu illusion: having a feeling of
familiarity in a situation that is objectively
unfamiliar or new.
• Share your own accounts of Deju Vu
experiences…………….
26
Deju Vu
More than 50 surveys of the phenomenon reveal that
the déjà vu experience:
• decreases with age and increases with education
and income.
• is more common in persons who travel, remember
their dreams, and have liberal political and
religious beliefs.
• is most likely to be triggered by a general physical
context, although spoken words alone sometimes
produce the illusion.
27
Deju Vu
More than 50 surveys of the phenomenon reveal that
the déjà vu experience:
• is experienced mainly when people are indoors,
engaged in leisure activities or relaxing, and in the
company of friends.
• is relatively brief—10 to 30 seconds—and is more
frequent in the evening than in the morning, and on
the weekend than on weekdays.
• is responded to more positively than negatively,
with people typically indicating they are surprised,
curious, or confused.
28
Deju Vu
• Arises from biological dysfunction,
divided perception, or implicit familiarity
in the absence of explicit recollection.
• From the biological perspective, incoming
sensory data follow several different
pathways to the higher processing centers of
the brain. A neurochemical event that
slightly alters transmission speed in one
pathway could lead to the illusion of déjà
vu.
29
Deju Vu
• That is, the slight delay in the speed of one
pathway relative to another could cause the
brain to interpret the data as independent
and separate copies of the same experience,
even though the two impressions are only
milliseconds off.
30
Deju Vu
• Déjà vu could also result from a perceptual
experience that is subjectively split into two parts.
That is, a fully processed perceptual experience
that matches a minimally processed impression
received moments earlier could produce a strong
feeling of familiarity.
• The disconnection between the two perceptual
impressions could result from a physical
distraction or even from a mental distraction such
as when we momentarily retreat into our inner
thoughts and reflections.
31
Deju Vu
• The phenomenon of inattentional blindness,
in which people miss something that is right
in front of them, demonstrates how
perceptual experience can be split into two
parts.
• A clearly visible item can be overlooked if
one’s attention is directed elsewhere. Even
though we may be oblivious to this clearly
visible stimulus, it still registers as
demonstrated by implicit memory tests.
32
The Pollyanna Principle
• The Pollyanna Principle states that
pleasant items and events are usually
processed more efficiently and accurately
than less pleasant items.
33
Implicit and Explicit Memory
• Studies of brain-damaged patients who suffer
amnesia reveal two types of memory.
• Implicit memory (procedural memory) is
retention without conscious recollection (of
skills, preferences, and dispositions).
• Explicit memory (declarative memory) is the
memory of facts and experiences that one can
consciously know and “declare.”
• This dual-memory system helps explain infantile
amnesia.
34
Implicit and Explicit Memory
• The hippocampus is a limbic system
structure that plays a vital role in the
gradual processing of our explicit
memories into long-term memory.
• When monkeys and people lose their
hippocampus to surgery or disease, they
lose most of their recall for things learned
during the preceding month.
35
Implicit and Explicit Memory
• Older memories remain intact, suggesting
that the hippocampus is not the permanent
storehouse, but a loading dock that feeds
new information to other brain circuits for
permanent storage.
• Implicit memories are processed by the
more ancient cerebellum.
36
Implicit and Explicit Memory
• Research with rabbits in which different
parts of the neural pathway were temporarily
deadened during eye-blink training
pinpointed implicit memory in the
cerebellum at the back of the head.
37
Figure 9.13 Memory subsystems
38
Myers: Psychology, Eighth Edition
Copyright © 2007 by Worth Publishers
Recall, Recognition, and Relearning
• Recall is a measure of memory in which the
person must retrieve information learned
earlier, as on a fill-in-the-blank test.
• Recognition is a measure in which a person
need only identify items previously
learned, as on a multiple-choice test.
39
Recall, Recognition, and Relearning
• Relearning is a memory measure that
assesses the amount of time saved when
relearning previously learned information.
• Tests of recognition and relearning reveal
that we remember more than we recall.
40
Retrieval Cues and Stored Memories
• We can think of a memory as held in storage by a
web of associations.
• Retrieval cues are bits of related information we
encode while encoding a target piece of
information.
• They become part of the web.
• To retrieve a specific memory, we need to identify
one of the strands that leads to it, a process called
priming.
• Activating retrieval cues within our web of
associations aids memory.
41
How Context Can Affect Retrieval
• Retrieval is sometimes aided by returning to
the original context in which we
experienced an event or encoded a thought.
• It can flood our memories with retrieval
cues that lead to the target memory.
42
How Context Can Affect Retrieval
• Sometimes, being in a context similar to
one we’ve been in before may trick us into
unconsciously retrieving the target
memory.
• The result is a feeling that we are reliving
something that we have experienced
before—a phenomenon known as déjà vu.
43
The Impact of Internal States on
Retrieval.
• State-dependent memory is the tendency to recall
information best in the same emotional or
physiological state as when the information was
learned.
• Memories are somewhat mood-congruent.
• While in a good or bad mood, we often retrieve
memories consistent with that mood.
• Moods also prime us to interpret others’ behavior
in ways consistent with our emotions.
44
A Test for Recall: Can You Write
Down the Names of Santa’s Nine
Reindeer?
45
Now Try Recognizing the Names
(Need Help? Answers Appear in
Appendix B)
•
•
•
•
•
•
•
A) Rudolph
B) Dancer
C) Cupid
D) Lancer
E) Comet
F) Vixen
G) Blitzen
•
•
•
•
•
•
•
H) Crasher
I) Donner
J) Prancer
K) Sunder
L) Thunder
M) Dasher
N) Donder
46
Forgetting
• The capacity to forget useless or out-of-date
information is helpful.
• Because of his inability to forget, the
Russian memory whiz S found it more
difficult than others to think abstractly—to
generalize, to organize, to evaluate.
• Without an ability to forget we would be
overwhelmed by out-of-date and irrelevant
information.
47
Forgetting
• Our memories fail us:
– through forgetting (absent-mindedness,
transience, and blocking),
– through distortion (misattribution,
suggestibility, and bias), and
– through intrusion (persistence of unwanted
memories).
48
The Role of Encoding Failure in
Forgetting
• One explanation for forgetting is that we fail to
encode information for entry into our memory
system.
• Without effortful processing, much of what we
sense we never notice or process.
• For example, although most people in the United
States have probably looked at thousands of
pennies, when tested on specific features they have
difficulty recognizing the real thing.
49
Figure 9.19 Test your memory
50
Myers: Psychology, Eighth Edition
Copyright © 2007 by Worth Publishers
Storage Decay& Ebbinghaus’
Forgetting Curve.
• Memories may fade after storage.
• From his research on learning and retention,
Ebbinghaus found that forgetting occurs rapidly
at first, and then levels off.
• This principle became known as the forgetting
curve.
• Storage decay may reflect a gradual fading of the
physical memory trace. Another possible
explanation is that we simply can’t retrieve the
information.
51
Proactive and Retroactive Interference
• Retrieval failure can occur if we have too
few cues to summon information from
long-term memory.
• It may also happen when old and new
information compete for retrieval.
52
Proactive and Retroactive Interference
• In proactive interference, something we
learned in the past interferes with our
ability to recall something we have
recently learned.
• In retroactive interference, something we
have recently learned interferes with
something we learned in the past.
53
Two Forms of Interference
54
Freud’s Concept of Repression
• With his concept of repression, Sigmund
Freud proposed that our memories are selfcensoring.
• To protect our self-concepts and to
minimize anxiety, we may block from
consciousness painful memories and
unacceptable impulses.
55
Freud’s Concept of Repression
• In Freud’s view, this motivated forgetting
submerges memories but leaves them
available for later retrieval under the right
conditions.
• Increasing numbers of memory researchers
think repression rarely, if ever, occurs.
• However, weak evidence for his theories.
56
Memory Retrieval Failure
• Bower argues that retrieval failure is the
largest contributor to forgetting.
• One important implication of a retrieval
view of forgetting is that some cues will fail,
whereas others will succeed in retrieving
one and the same memory trace.
• Failure to recognize this reality can readily
lead us to falsely accept a belief in
repression.
57
Memory Retrieval Failure
• Memories are like ‘responses’ waiting for
the right ‘stimulus’ to release them.”
58
Suppressed Memory
• Freud’s concept of repression raises the
broader question of whether people can
influence the content of their memories.
• There must exist a collection of executive
control functions,” with people influencing
the content of their own memories.
59
Suppressed Memory
• Anderson’s interest in memory control was sparked
by the finding that victims of childhood abuse are
more likely to inhibit memories if the perpetrator is
a trusted caregiver than if he or she is a stranger.
• Presumably, the known abuser is providing a
constant memory cue so the victim may have to
actively suppress the memory in order to go
forward with life.
• In general, memory inhibition may be adaptive. It
may be counterproductive to remember yesterday’s
parking spot or the name of last year’s lover.
60
Misinformation and Imagination can
Distort our Memory
• Memories are not stored as exact copies, and
they certainly are not retrieved as such.
• Rather, we construct our memories, using
both stored and new information.
61
Misinformation and Imagination can
Distort our Memory
• In many experiments around the world,
people have witnessed an event, received
or not received misleading information
about it, and then taken a memory test.
• The repeated result is a misinformation
effect: After exposure to subtle
misinformation, many people
misremember.
62
Misinformation and Imagination can
Distort our Memory
• Asking leading questions can plant false
memories.
• As people recount an experience, they fill
in their memory gaps with plausible
guesses.
• Other vivid retellings may also implant
false memories.
• Even repeatedly imagining and rehearsing
nonexistent events can create false
memories.
63
The Misinformation Effect:
Loftus
1. When are people susceptible to misinformation?
• People are particularly prone to misinformation
when the passage of time allows the original
memory to fade.
• This finding leads to the discrepancy detection
principle, which states that recollections are
more likely to change if a person does not
immediately detect discrepancies between
postevent information and memory for the
original event.
64
The Misinformation Effect
1. When are people susceptible to
misinformation?
• Consistent with this principle is the finding
that people are more likely to be
influenced if they are exposed to
misinformation that is subtle.
65
The Misinformation Effect
2. Who is susceptible to misinformation?
• Young children are particularly susceptible
to the misinformation effect.
• Also, those over age 65.
66
The Misinformation Effect
3. What happens to the original memory?
• Some have argued that the original memory
traces are changed by postevent information.
• For example, new information may update the
previously formed memory. Others have argued
that misinformation does not affect memory at all
but merely influences the reports of subjects who
did not encode the original event in the first
place.
67
The Misinformation Effect
•
•
Or, if they have encoded the event, they
select the misleading information because
they conclude it must be correct.
Several lines of research indicate that
misinformation does impair the ability to
remember original details.
68
The Misinformation Effect
4. Do people genuinely believe the
misinformation?
• One reason to think that subjects believe in
their misinformation memories is that they
often express these memories with great
confidence.
69
The Misinformation Effect
4. Do people genuinely believe the
misinformation?
• It seems reasonable that if subjects still
showed evidence of the misinformation
effect, then they truly believed they saw
the details suggested in the postevent
narrative at the time of the original event.
• This is in fact what the research has
found.
70
The Misinformation Effect
Loftus concludes that misleading information
can turn a lie into memory’s truth.
It can cause people to believe that they saw
things that never really existed or that they
saw things differently from the way things
actually were.
71
Source Amnesia’s & False Memories
• When we encode memories, we distribute
different aspects of them to different parts
of the brain.
• Our memory for the source of an event is
particularly frail.
• In source amnesia, we attribute to the
wrong source an event that we have
experienced, heard about, read about, or
imagined.
72
Source Amnesia’s & False Memories
• Thus, we may recognize someone but
have no idea where we have seen the
person.
• Or we imagine or dream an event and
later are uncertain whether it actually
happened.
• Source amnesia is one of the main
components of false memories.
73
True & False Memories
• Unreal memories feel like real
memories.
• Neither the sincerity nor the longevity
of a memory signifies that it is real.
• The most confident and consistent
eyewitnesses are often not the most
accurate.
74
True & False Memories
• Memories of imagined experiences are
usually limited to the gist of the
supposed event—the meanings and
feelings we associate with it.
• True memories contain more details
than imagined ones.
75
• Creating a false memory exercise
76
Children’s Reports of Abuse
• A supporting argument is that even very
young children can accurately recall events
if a neutral person talks to them in words
they can understand, asks nonleading
questions, and uses the cognitive interview
technique.
• A challenging argument is that
preschoolers are more suggestible than
older children or adults, and they can be
induced, through suggestive questioning,
77
to report false events.
Repressed Memories
• Many states enacted legislation that enabled
people previously barred from suing by
statutes of limitations to sue for injury
suffered as a result of childhood abuse at
any time within three years of the time they
remembered the abuse.
78
Repressed Memories
• Since most empirical studies of childhood
memory suggest that people’s earliest
recollections do not date back before the age
of 3, questions ought to be raised about the
accuracy of repressed memory claims that
refer to events occurring when the child was
1 year old or less.
79
Repressed Memories
• Perhaps the most important and difficult
question concerns the accuracy of the
memories. Clearly, the data suggest that
therapists believe in their clients’ memories.
• They point to symptomatology as their
evidence and are impressed with the
emotional pain that accompanies the
expression of the memories.
80
Repressed Memories
• There may be at least two ways in which false
memories, however honestly believed, could come
about.
• First, an internal drive to manufacture an abuse
memory may come about as a way to provide a
screen for less tolerable experiences of childhood.
• Manufacturing a fantasy of abuse with its clear-cut
distinction between good and evil may provide a
logical explanation for confusing experiences and
feelings.
81
Repressed Memories
• Second, external sources, including popular
writings such as The Courage to Heal and
therapists’ suggestions may feed into the
construction of false memories.
• Evidence comes from therapist accounts of what is
appropriate to do with clients (e.g., “It is crucial . .
that clinicians ask about sexual abuse during every
intake”), client accounts of what happened during
therapy (clients reporting an inability to recall
abuse that therapists say is likely to have
occurred), sworn statements of clients and
therapists during litigation, and taped interviews of
82
therapy sessions.
Repressed and Recovered Memories
of Childhood Sexual Abuse.
• Innocent people have been falsely
convicted of abuse that never happened, and
true abusers have used the controversy over
recovered memories to avoid punishment.
• Forgetting of isolated past events, both
negative and positive, is an ordinary part
of life. Cued by a remark or an experience,
we may later recover a memory.
83
Repressed and Recovered Memories
of Childhood Sexual Abuse.
• Controversy, however, focuses on
whether the unconscious mind forcibly
represses painful experiences and
whether they can be retrieved by
therapist-aided techniques.
• Memories “recovered” under
hypnosis or drugs are especially
unreliable as are memories of things
happening before age 3.
84
Repressed and Recovered Memories
of Childhood Sexual Abuse.
• Traumatic experiences are usually
vividly remembered, not banished
into an active but inaccessible
unconscious.
85
Memory & Effective Study Techniques
• The psychology of memory suggests
several effective study strategies.
• These include:
– overlearning, using spaced practice;
– active rehearsal; making new material
personally meaningful by relating it to
what is already known;
– mnemonic techniques;
86
Memory & Effective Study Techniques
• These include (Continued):
– mentally recreating the contexts and moods in which the
original learning occurred in order to activate retrieval
cues;
– recording memories before misinformation can corrupt
them;
– minimizing interference, for example, by studying just
before sleeping; and testing one’s knowledge both to
rehearse it and to determine what must still be learned.
– Specific, vs. general instructions
87
Figure 9.28 Levels of analysis for the study of
88memory
Myers: Psychology, Eighth Edition
Copyright © 2007 by Worth Publishers