Transcript PPT

Learning Objectives: Memory
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What is memory? Why is it so susceptible to errors?
What are source misattribution and flashbulb memories?
What are the 3 circumstances under which confabulation is
likely to take place?
What can cause errors in eyewitness testimony?
What is the difference between recognition and recall?
Implicit and explicit memory?
What is the Three-Box model of memory?
What are the 3 boxes in the “three-box model” of memory?
chapter 8
Memory
Memory is the capacity to retain and retrieve
information.
Memory is not a library, recorder, or camera
It is selective and reconstructive
• we don’t remember EVERYTHING
•we remember new information in the context of
information we already know
chapter 8
Reconstruction of Memories:
Possible Errors
Source misattribution
Fading Flashbulb
Confabulation
Power of Suggestion
chapter 8
Reconstruction of Memories:
Possible Errors
Source misattribution
The inability to distinguish what you originally
experienced from what you heard or were told later
about an event
Flashbulb Memories
Flashbulb Memories
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Some unusual, shocking, or tragic events hold a special
place in memory.
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typically hold an amazing amount of photographic detail
6 categories of information
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Location
Ongoing Events
The informant
Emotional Effects in others
Emotional Effects in self
Aftermath/Consequentiality
chapter 8
Reconstruction of Memories:
Possible Errors
The Fading Flashbulb
Even such vivid memories tend to fade over time and
become mixed with a little fiction or affected by source
misattribution
Over time even flashbulb memories will contain just as many
inconsistencies as everyday memories.
chapter 8
Reconstruction of Memories:
Possible Errors
Confabulation
Confusion of an event that happened to someone else with one that
happened to you, or. . .
A belief that you remember something when it never actually happened
Conditions of Confabulation
Confabulation is most likely when:
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You have thought or heard about the event many times.
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The image of the event contains many details.
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The event is easy to imagine
chapter 8
Reconstruction of Memories:
Possible Errors
The Power of Suggestion:
Eyewitnesses are not always reliable
Factors influencing eyewitness accuracy:
1. Cross race identification
2. Question wording (e.g., “crashed” vs “hit”)
3. Misleading information
chapter 8
Children’s testimony
Under what conditions are children more
suggestible?
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When they are very young
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When interviewers’ expectations are clear
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When other children’s memories for events are accessible
chapter 8
Explicit memory
Conscious, intentional recollection of an
event or item of information.
How to measure explicit memory:
Recall: The ability to retrieve and reproduce from
memory previously learned material
Recognition: The ability to identify previously
encountered material
chapter 8
Implicit memory
Unconscious retention in memory, as evidenced by the effect
of a previous experience or previously encountered
information on current thoughts or actions.
How to measure:
Relearning
Compares the time required to relearn material with the time used in the
initial learning of the material.
Priming
A person reads or listens to information and is later tested to see whether
the information affects performance on another type of task
- word-stem completion
Models of Memory
• Information-Processing Models
• Mind likened to a computer
• Encode, storage, retrieval
• Three-Box Model of Memory
• Sensory Registry
• Short-Term Memory
• Long-Term Memory
chapter 8
Three-box model of
memory
Last Class in Review
• Memory
• Retaining and retrieving information
• Selective and reconstructive
• Reconstructive = susceptible to errors
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Source misattribution
Fading Flashbulb (flashbulb memories)
Confabulation
Power of Suggestion (eyewitness testimony)
• Explicit Memory
– Recall
– Recognition
• Implicit Memory
– Priming
– Relearning
• Three-Box Model of Memory
Learning Objectives: Memory
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What are the 3 boxes in the three-box model of memory?
What is the sensory register?
What are the capacity limits of short-term memory? What is
chunking and how does it help overcome these capacity limits?
How is long-term memory organized? What are semantic
categories?
What are the differences in procedural, declarative, semantic, and
episodic memories?
What are the primacy and recency effects?
What are some effective strategies for encoding information in
storage for long-term memory?
How do decay, replacement, and interference each contribute to
forgetting?
What evidence is there both for and against the existence and
accuracy of repressed memories?
What are 4 explanations of childhood amnesia?
What are some techniques that can help you better retain the
information that your study?
chapter 8
Three-box model of
memory
chapter 8
Sensory Registry
• Fleeting, Brief, Holding Bin
• Large Capacity
• “Holding bin” for sensory information
• Sensory subsystems
• Extremely accurate and detailed images from senses
• Brief retention of images
• 0.5 seconds visual sensory images
• 2 seconds auditory sensations
• Prevents “double exposures”
• If it does not go into STM, it is FORGOTTEN
chapter 8
Short-term memory
(STM)
• “Scratch Pad” for new memories
OR “Working memory” on a computer
• Temporary
• 30 seconds to a few minutes
• Information actively “in use”
• Limited capacity
•Encoded sensory image
• Chunking – allows us to remember the beginning of a
sentence or a long string of numbers
 7+2
• Remember H.M.?
chapter 8
The value of chunking
X IBM CIA FBI CBS MTV
See how much easier it was to remember 6 chunks of
information vs. 16 individual letters
Chunking – allows us to remember the beginning of a
sentence or a long string of numbers, by grouping them
together into meaningful units
chapter 8
Short-term memory
(STM)
Working memory
A memory system which includes STM and mental processes
that control retrieval of information from long-term memory (LTM)
and interpret that information appropriately for a given task
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Short-term Memory
Rehearsal and Retrieval of info from LTM
Interpretation of info from LTM for task at hand
Remember H.M.?
chapter 8
Long-term memory
The memory system involved in the long-term
storage of information
• Helps us LEARN about ourselves and the environment
• No real limits
• How is information in LTM organized?
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Semantic categories
Sound and form (tip-of-the-tongue)
Familiarity
Relevance
Association with other information
chapter 8
Long-term memory
Other types of conceptual maps:
Slide Trays
Shower
APA
Store
Party
San Diego
chapter 8
Long-term memory
The memory system involved in the
long-term storage of information
• Helps us LEARN about ourselves and the
environment
• No real limits
• Semantic categories
• Organizing words (or their concepts) into groups or
clusters corresponding to semantics (meaning)
chapter 8
Conceptual grid
chapter 8
Long-term memory
Other types of conceptual maps:
Slide Trays
Shower
APA
Store
Party
San Diego
chapter 8
Types of long-term
memories
Types of Long-Term Memory
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Procedural Memories– “knowing how”
– Once learned they are implicit
– Actions or skills
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Declarative Memories – “knowing that”
– Explicit
– Facts, rules, concepts, events
1. Semantic Memories
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Internal representations of the world
– Rules, facts, concepts
2. Episodic Memories
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Internal representations of experienced events
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Your first date with your significant other
How your dog tore up the back door
What is the
definition of
Classical
Conditioning?
chapter 8
Your turn
What kind of memory is your memory for
the fact that the earth is round?
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Procedural memory
Semantic memory
Episodic memory
Flashbulb memory
chapter 8
Serial-position effect
The tendency for
recall of first and last
items on a list to
surpass recall of
items in the middle of
the list
chapter 8
Serial-position effect
The tendency for recall of first and
last items on a list to surpass recall of
items in the middle of the list
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Primacy Effect
STM empty = easier
to transfer to LTM
Hardest to
remember
STM crowded making it
difficult to make into
LTM
Recency Effect
Still in STM at
time of recall
chapter 8
Your turn
You are asked to recall the following list of letters:
Z, S, E, R, F, V, B, H, U, I, K, M, N, G, B, F, O
Which letters are you most likely to remember in longterm memory?
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Z, S, E, R
F, V, B, H
U, I, K, M
G, B, F, O
How do we remember?
STM  LTM
• Encoding helps us remember
– extracting the main points and
summarizing them
– Effortful encoding
• Select main points
• Label concepts
• Associate information with personal experience
How do we encode memories?
STM  LTM
• Rehearsal
• Mnemonics
chapter 8
Rehearsal
A technique for keeping information in STM and
helping it move along to LTM
Types of Rehearsal:
• Maintenance rehearsal: rote repetition of
material in order to maintain its availability in
memory
• Elaborative rehearsal: association of new
information with already stored knowledge and
analysis of the new information to make it
memorable
– the processing of meaning, rather than simply the physical
or sensory features of a stimulus
– Prolongs retention of information
chapter 8
Mnemonics (neh-MON-ics)
Strategies and tricks for improving memory,
such as use of a verse or a formula
STM  LTM
Helps retain and retrieve information
But may not help you understand it
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Acronyms
Rhymes and Catch Phrases
Method of Loci
chapter 8
Mnemonics - Examples
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Acronyms
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Kids
Prefer
Cheese Over Fried
Kingdom Phylum Class
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Green Spinach
Order Family Genus Species
Every Good Boy Does Fine
Notes on a treble clef
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Rhymes and Catch Phrases
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I before E, except after C
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Thirty days hath November, April, June, and September.
Of twenty-eight is but one
And all the remnant thirty-one
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A,B,C….next time won’t you sing with me
Method of Loci
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Mentally positioning things to remember in a well-known room
chapter 8
Method of Loci
Candles
Soda
Cake
Balloons
Balloons
Soda
Cake
Chips
Chips
Candles
Why can’t I remember?!?
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Decay
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Information in memory eventually disappears if it is not accessed
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Applies more to short-term than long-term memory
Replacement
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New information replaces old information
Interference
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Similar items interfere with one another.
4. Cue-Dependent Forgetting
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Inability to retrieve information stored in memory due to
insufficient recall cues
5. Amnesia
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The loss of memory for important personal information
Brain injury, disease, psychological (psychogenic amnesia)
Repression: the involuntary pushing of a threatening or
upsetting information into the unconscious
chapter 8
Interference
Retroactive interference:
recently learned material
interferes with previously
stored information
New  Old
Retroactive interference
French
Spanish
Learned first
Learned second
Proactive interference
Proactive interference:
previously stored material
interferes with
remembering recently
learned material
Old  New
Old Phone
Number
New Phone
Number
Learned first
Learned second
chapter 8
When should we question
recovered memories?
•If a person claims memories of first year or
two of life
•If over time the memories become more and
more implausible
•If therapist used suggestive techniques such
as hypnosis, dream analysis, age regression,
guided imagery, or leading questions
chapter 8
What is your earliest
memory?
Write down one of the first/earliest events you can
clearly remember in your life. Try to make sure that it
isn’t subject to source misattribution or confabulation.
How old were you?
- for most it won’t be before your 3rd or 4th birthday
Why don’t you remember something from earlier in life?
chapter 8
Childhood amnesia
The inability to remember events and
experiences that occurred during the first
two or three years of life
Cognitive explanations:
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Lack of sense of self
Impoverished encoding
A focus on the routine
Different ways of thinking about the world
What is happening in the brain?
• Stem cells and Neurogenesis
– Fred Gage, Salk Institute
– Stem cells: unspecialized (immature) cells that
retain the ability to divide and mature into specific
cell types
– Neurogenesis: The process by which new nerve
cells are generated
– In response to experience stem cells divide and
mature
• Environmental enrichment enhances neurogenesis
• Exercise – “use it or lose it”
• Long-term potentiation (LTP)
– Physical change in the structure of the neuron
– Proposed neural mechanism by which STM  LTM