Transcript Encoding

Memory
 Memory
 persistence of learning over time
as a result of storing and retrieving
information
 Flashbulb Memory
 a clear memory of an emotionally
significant moment or event (Ex.
your location on 9/11
Memory
 1. Encoding
 The processing of information into the
memory system (extract meaning)
 2. Storage
 The retention of encoded information over
time
 3. Retrieval
 The process of getting information out of
memory
Connectivism
 A Modern Model of Memory
 Memories are extracted from
interconnected neural networks
 Specific memories arise from
particular activation patterns within
the networks
3 Stages of Memory
Formation
 Atkinson & Shiffrin (1968)
 1. Sensory Memory
 the immediate, initial recording of sensory
information; very fleeting
 2. Working Memory (a/k/a Short-Term)
 focuses more on the processing of briefly
stored information
 pulls from both incoming stimuli and longterm memory
3 Stages of Memory
Formation
 3. Long-Term Memory
 the relatively permanent and limitless
storehouse of the memory system
 knowledge, skills, experience
A Simplified Memory
Model
Sensory input
Attention to important
or novel information
Encoding
External
events
Sensory
memory
Short-term
memory
Encoding
Unconscious
Processing
Long-term
memory
Retrieving
Encoding: Getting
Information In
Encoding
Automatic
Effortful
Effortful
Encoding
 Automatic Processing
 unconscious encoding of incidental
information
 space
 time
 frequency
 well-learned information
 word meanings
 we can learn automatic processing
 driving, a second language
Encoding
 Effortful Processing
 requires attention and conscious
effort
 Requires rehearsal
 conscious repetition of information
 to maintain it in consciousness
 to encode it for storage
Encoding
 Hermann Ebbinghaus (1850-1909)
 Wanted to scientifically study his own
memory and forgetting
 used nonsense syllables
 TUV ZOF GEK WAV
 the more times practiced on Day 1,
the fewer repetitions to relearn on
Day 2
Encoding
Time in
minutes
taken to
relearn
list on
day 2
20
15
10
5
0
8
16
24
32
42
53
Number of repetitions of list on day 1
64
Encoding
 The more time we spend learning
novel information, the more we
retain
 Spacing Effect
 distributed practice yields better
long-term retention than massed
practice (“cramming”)
Encoding
 Serial Positioning Effect
 tendency to recall best the first
and last items in a list
Encoding: Serial
Position Effect
Percent
age of
words
recalled
RED:
immediate
recall; “recency
effect”
90
80
70
60
BLUE: later
recall;
“primacy
effect”
50
40
30
20
10
0
1
2
3
4 5 6 7 8
Position of
word in list
9
10 11 12
What Do We Encode?
 Semantic Encoding
 encoding of meaning
 including meaning of words
 Acoustic Encoding
 encoding of sound
 especially sound of words
 Visual Encoding
 appearance of the letters
Encoding
Encoding
 Self-Reference Effect
 We have especially good recall of
information that we can meaningfully
relate to ourselves
Visual Encoding
 Imagery
 mental pictures
 a powerful aid to effortful processing,
especially when combined with semantic
encoding
 Mnemonics
 memory aids
 especially those techniques that use vivid
imagery and organizational devices
Encoding: Chunking
 Chunking
 organizing items into familiar, manageable
units
 like horizontal organization--1776149218121941
 often occurs automatically
 use of acronyms
 HOMES--Huron, Ontario, Michigan, Erie, Superior
 ARITHMETIC--A Rat In Tom’s House Might Eat
Tom’s Ice Cream
Encoding: Chunking
 Organized information is more easily recalled
Encoding:
Heirarchies
 Hierarchies
 complex information broken down into broad concepts and
further subdivided into categories and subcategories
Encoding
(automatic
or effortful)
Meaning
(semantic
Encoding)
Imagery
(visual
Encoding)
Chunks
Organization
Hierarchies
Storage:
Retaining Information
 Iconic Memory
 a fleeting “photographic memory”
 lasts no more that a few tenths of a
second
 Echoic Memory
 momentary sensory memory of auditory
stimuli
 lasts 3 to 4 seconds
Storage: Working/
Short-Term Memory
Percentage
90
who recalled
consonants 80
70
60
50
40
30
20
10
0
 Short-Term
Memory
3
6
9
12
15
18
Time in seconds between presentation
of contestants and recall request
(no rehearsal allowed)
 limited in
duration and
capacity
 “magical”
number 7+/-2
Storage: Working/
Short-Term Memory
 At any given moment, we can
consciously process only a very
limited amount of information.
Storage:
Long-Term Memory
 How does long-term storage work?




Karl Lashley (1950)
rats learn maze
cut out pieces of cortex
retest memory
 Result: Rats always retained at least a
partial memory of how to navigate the maze
 Conclusion: We do not store memories in
single, specific locations.
Storage:
Long-Term Memory
 Synaptic changes
 Long-term Potentiation
 increase in synapse’s firing potential after brief,
rapid stimulation
 Strong emotions make for stronger
memories
 some stress hormones boost learning and retention
Storage:
Long-Term Memory
 Amnesia--the loss of memory
 Explicit Memory
 memory of facts and experiences that one can
consciously know and declare
 also called “declarative” memory
 hippocampus—cetner in the limbic system that
helps process explicit memories for storage
 Implicit Memory
 retention independent of conscious recollection
 also called “nondeclarative” or “procedural”
memory
Storage: Long-Term
Memory Subsystems
Types of
long-term
memories
Explicit
(declarative)
With conscious
recall
Facts-general
knowledge
(“semantic
memory”)
Personally
experienced
events
(“episodic
memory”)
Implicit
(nondeclarative)
Without conscious
recall
Skills-motor
and cognitive
Dispositionsclassical and
operant
conditioning
effects
Storage:
Long-Term Memory
 Hippocampus is critical for explicit memory
Hippocampus
Storage:
Long-Term Memory
 Cerebellum is critical for implicit memory
Retrieval: Getting
Information Out
 Recall
 measure of memory in which the
person must retrieve information
learned earlier
 as on a fill-in-the blank test
 Recognition
 Measure of memory in which the
person has only to identify items
previously learned
 as on a multiple-choice test
Retrieval
 Relearning
 quicker “relearning” also
indicates that memory
 Priming
 activation, often unconsciously,
of particular associations in
memory
 remember our unit on
subliminal cues?
Retrieval Cues:
Influence of Context
Percentage of
words recalled
Conclusion:
There is
greater recall
when learning
and testing
contexts are
the same
40
30
20
10
0
Water/
land
Land/
water
Different contexts for
hearing and recall
Water/
water
Land/
land
Same contexts for
hearing and recall
Retrieval Cues
 Deja Vu (French)--already seen
 cues from the current situation may subconsciously
trigger retrieval of an earlier similar experience
 "I've experienced this before."
 Mood-congruent Memory
 tendency to recall experiences that are consistent with
one’s current mood
 memory, emotions, or moods serve as retrieval cues
 State-dependent Memory
 what is learned in one state (while one is high, drunk, or
depressed) can more easily be remembered when in same
state
Forgetting
 Forgetting as encoding failure
 Information never enters the long-term
memory
Attention
External
events
Short- Encoding
Sensory
term
memory Encoding
memory
Encoding
failure leads
to forgetting
Longterm
memory
Forgetting
 Forgetting as
encoding failure
 Which penny is the
real thing?
Forgetting
Percentage of
list retained
when
relearning
 Ebbinghaus
forgetting
curve over
30 days-initially
rapid, then
levels off
with time
60
50
40
30
20
10
0
12345
10
15
20
25
Time in days since learning list
30
Forgetting
 The forgetting curve for Spanish learned in school
Percentage of 100%
original
90
vocabulary
80
retained
Retention
drops,
70
then levels off
60
50
40
30
20
10
0
1 3 5
9½
14½
25
35½
49½
Time in years after completion of Spanish course
Retrieval
 Forgetting can result from failure to
retrieve information from long-term
memory
Attention
External
events
Sensory
memory
Encoding
Encoding
Short-term
Long-term
memory
Retrieval memory
Retrieval failure
leads to forgetting
Forgetting as
Interference
 Learning some items may disrupt
retrieval of other information
 Proactive (forward acting) Interference
 disruptive effect of prior learning on recall
of new information
 Retroactive (backwards acting)
Interference
 disruptive effect of new learning on recall of
old information
Forgetting as
Interference
Forgetting
 Retroactive Interference
Percentage
of syllables
recalled
90%
Without interfering
events, recall is
better
80
After sleep
70
60
50
40
30
20
10
After remaining awake
0
1
2
3
4
5
6
7
Hours elapsed after learning syllables
8
Forgetting
 Forgetting can
occur at any
memory stage
 As we process
information,
we filter, alter,
or lose much
of it
ForgettingInterference
 Motivated Forgetting
 people unknowingly revise memories
 Repression
 defense mechanism that banishes from
consciousness anxiety-arousing thoughts,
feelings, and memories
Memory Construction
 We filter information and fill in
missing pieces
 Misinformation Effect
 incorporating misleading information into
one's memory of an event
 Source Amnesia
 attributing to the wrong source an event
that we experienced
Memory Construction
Depiction of actual accident
 Eyewitnesses
reconstruct
memories when
questioned
Leading question:
“About how fast were the cars
going when they smashed into
each other?”
Memory
construction
Memory Construction
 Memories of Abuse
 Repressed or Constructed?
 Child sexual abuse does occur
 Some adults do actually forget such episodes
 False Memory Syndrome
 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
Memory Construction
 Most people can agree on the following:
Injustice happens
Incest happens
Forgetting happens
Recovered memories are commonplace
Memories recovered under hypnosis or drugs
are especially unreliable
 Memories of things happening before age 3
are unreliable
 Memories, whether false or real, are upsetting
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