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


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


Implicit Memory- Cerebellumretention without conscious recollectionProcedural memoriesmotor and cognitive skillsdispositions- conditioning


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)


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



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Chapter 9- Memory