Chapter 9- Memory
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Transcript of Chapter 9- Memory
Chapter 9- Memory
Memorypersistence of learning over time via the
storage and retrieval of informationAny indication learning has persisted over
timeFlashbulb Memory
a clear memory of an emotionally significant moment or event
Memory
Processes of Memory
Three Memory Processes:EncodingStorage Retrieval
Encodingthe processing of information into the memory system
(using your senses)Storage
the retention of encoded information over timeRanges from a few seconds to much longer
Retrievalprocess of getting information out of memory
Ease of retrieval depends on how efficiently it was encoded and stored.
Memory
Three Box Model of Memory
Sensory Memory• Some memory
is lost because it is not encoded
Short-Term Memory• More Memory
is lost because it is not encoded
Long-Term Memory• Some
information is lost due to retrieval failure
3 Stages of MemorySensory Memory
Short-Term Memory
Long-Term Memory
Capacity Virtually everything you see or hear at one instant
About 7 items in healthy adults
Vast; uncountable
Duration Fraction of a second
Less than 20 seconds if not rehearsed
Perhaps a lifetime
Example You see something for an instant and then someone asks you to recall one detail.
You look up a telephone number and remember it long enough to dial it.
You remember the house you lived in when you were 7 years old.
Sensory Memory Split-second holding tank, holds info less
than a second Demonstrated by George Sperling
Flashed a grid of nine letters for 1/20th of a second, participants could recall either the top, middle, or bottom rows perfectly
Tone (high, medium, or low) used as a cue as to what row to remember
Entire grid is held in memory for a split second
Q L 5
3 P X
T 7 V
Sensory Memory Iconic- visual Echoic-auditory (slightly longer- 3-4
seconds) Most of the information is never encoded-
selective attention What we are attending to or what we
consider to be important Cocktail party phenomenon
Short Term Memory (STM)activated memory that holds a few items brieflyEverything we are currently thinking aboutSometimes called working memorylook up a phone number, then quickly dial before the
information is forgottenLong Term Memory (LTM)
the relatively permanent and limitless storehouse of the memory system
Memory
Long-Term MemoryPermanent memory, unlimited capacityCan decay or fade
Episodic
• Memories of specific events
Semantic
• General knowledge of the world, stored as facts, meanings, and categories
Procedural
• Memories of skills and how to perform them; might be complicated to explain in words
Automatic Processingunconscious encoding of incidental information
spacetimefrequency
well-learned informationword meanings
we can learn automatic processingreading backwards
Encoding
Effortful Processingrequires attention and conscious effort
Rehearsalconscious repetition of information
to maintain it in consciousness to encode it for storage
Encoding
Levels of ProcessingAlternate way to think about memoryElaborately (Deeply) Processed-
will likely to be remembered later, more time spent studying
Maintenance (Shallowly) Processed- will be forgotten quickly (cramming)
Explains why we remember stories better than simple repetition
Ebbinghaus used nonsense syllables TUV ZOF GEK WAVthe more times practiced on Day 1, the
fewer repetitions to relearn on Day 2
Spacing Effectdistributed practice yields better long
term retention than massed practiceAka- cramming is not as effective!
Encoding
Also called the primary-recency effectWe tend to remember the first and the last
items on a list and forget those in the middle.
The Serial Position Effect
Encoding
Imagerymental picturesa powerful aid to effortful processing, especially when
combined with semantic encodingMnemonics
memory aidsespecially those techniques that use vivid imagery and
organizational devicesuse of acronymsHOMES- Huron, Ontario, Michigan, Erie, SuperiorPEMDAS- Please Excuse My Dear Aunt Sally
Encoding
1776149218121941
Chunkingorganizing items into familiar, manageable units
like horizontal organization- 1776149218121941often occurs automaticallyDOES NOT help with long term memory, instead increases
the amount of information in STM- “increases the magic number 7”
Encoding
Short Term Memory limited in duration and capacity“magical” number 7+/-2
Storage-Short Term Memory
Storage-Short Term Memory
0102030405060708090
3 6 9 12 15 18
Time in seconds between presentationof contestants and recall request
(no rehearsal allowed)
Percentagewho recalledconsonants
How does storage work? Karl Lashley (1950)
rats learn mazelesion cortex test memoryProved memories weren’t stored in specific places
Storage- Long Term Memory
Synaptic changesLong-term Potentiation
increase in synapse’s firing potential after brief, rapid stimulationWhen learning occurs, more neurotransmitter is released into the
synapse, neurons become more efficientAlcohol can disrupt memory formation by disrupting this process
Strong emotions make for stronger memoriessome stress hormones boost learning and retention
Storage- Long Term Memory
Amnesia- the loss of memoryExplicit Memory
memory of facts and experiences that one can consciously know and declare
Hippocampus- neural center in limbic system that helps process explicit memories for storage
AKA declarative
Storage- Long Term Memory
Implicit Memory- Cerebellumretention without conscious recollectionProcedural memoriesmotor and cognitive skillsdispositions- conditioning
Storage- Long Term Memory
Storage- Long Term Memory Subsystems
Types oflong-termmemories
Explicit(declarative)
With consciousrecall
Implicit(nondeclarative)
Without conscious recall
Facts-generalknowledge(“semanticmemory”)
Personally experienced
events(“episodic memory”)
Skills-motorand cognitive
Dispositions-classical and
operant conditioning
effects
MRI scan of hippocampus (in red)
Storage- Long Term Memory
Hippocampus
LT Stress
- It can
shrink!
Recallthe ability to retrieve info learned
earlier and not in conscious awareness-like fill in the blank test
Recognitionthe ability to identify previously
learned items-like on a multiple choice test
Retrieval- Getting Information Out
Relearningamount of time saved when relearning
previously learned informationPriming
activation, often unconsciously, of particular associations in memory
Retrieval
Reminders of information we could not otherwise recall
Guides to where to look for infoContext Effects
memory works better in the context of original learningHearing a songBeing in the same
classroom
Retrieval Cues
Mood Congruent Memorytendency to recall experiences that are consistent
with one’s current mood memory, emotions or moods serve as retrieval cuesState Dependent Memory
what is learned in one state (while one is high, drunk or depressed) can more easily be remembered when in same state
Retrieval Cues
Forgetting as encoding failure
Which penny is the real thing?
Forgetting
Ebbinghaus- forgetting curve over 30 days initially
rapid, then levels off with time
Forgetting
12345 10 15 20 25 30
10
20
30
40
50
60
0
Time in days since learning list
Percentage oflist retainedwhen relearning
The forgetting curve for Spanish learned in school
Forgetting
Retentiondrops,
then levels off
1 3 5 9½ 14½ 25 35½ 49½Time in years after completion of Spanish course
100%
90
80
70
60
50
40
30
20
10
0
Percentage oforiginal
vocabularyretained
Learning some items may disrupt retrieval of other informationProactive(forward acting) Interferencedisruptive effect of prior learning on
recall of new informationRetroactive (backwards acting) Interferencedisruptive effect of new learning on
recall of old information
Forgetting as Interference
Retroactive Interference
Forgetting
Without interferingevents, recall isbetterAfter sleep
After remaining awake
1 2 3 4 5 6 7 8Hours elapsed after learning syllables
90% 80 70 60 50 40 30 20 10 0
Percentageof syllables
recalled
ForgettingSensory memory - the senses momentarily register amazing detail
Short term memory - a few items are both noticed and encoded
Long-term storage - Some itemsare altered or lost
Retrieval from long-term memory - depending on interference, retrieval cuesmoods and motives, some things get retrieved, some don’t Information bits
Forgetting can occur at any memory stage
We filter information and fill in missing pieces
Misinformation Effectincorporating misleading information into
one's memory of an eventSource Amnesia
attributing to the wrong source an event that we experienced, heard about, read about, or imagined (misattribution)
Memory Construction
People fill in memory gaps with plausible guesses and assumptions
Imagining events can create false memories
Memory Construction
Eyewitnesses reconstruct memories when questioned
Memory ConstructionDepiction of actual accident
Leading question:“About how fast were the carsgoing when they smashed intoeach other?”
Memoryconstruction
http://www.youtube.com/watch?v=KrrNkY7G7_4