Download long-term memory

How do people remember things?
A look at processing models of memory and learning from the
cognitive perspective
The brain processing loop modeled after
computer processing

Brain is like a computer

Input

Process

Store

Retrieve

Reprocess

Output
Brain able to do
PARALLEL processing:
splitting ideas and
stimuli into different
components, sifting
through and integrating
things all at the same
time!
Or, to put it in the lingo of Psych...
Encode incoming sensory information
1.
a)
Perceive and consciously process information OR
b)
Bypass conscious perception straight to level 1, subconscious
processing and storage
Storage of information
2.

Theory is that brain deconstructs elements of sensory
experience, storing bits and pieces in different parts of brain.
Retrieval of memory
3.

Brain pulls all elements of experience/learning back together
for reprocessing
Quick experiment

On loose leaf, # 1-20

I will read you a category and a number (1st, 2nd or 3rd)

You will write down the 1st, 2nd, or 3rd thing that comes to mind when
you hear the category (depending on the number I provide you.)

EXAMPLE:
DOG 2nd
You write down the second thing that comes to mind after hearing the
word “dog”
It is CRITICAL that this be done independently and QUIETLY!
Red arrow equals encoding; blue arrow equals retrieval
(1968) Atkinson and Shiffrin The classic 3-stage processing model
Step 1: Sensory memory
Step 2: Short-term
memory
Step 1: Receive and encode sensory
input. This is a fleeting moment of
conscious awareness of incoming
information—Sperling’s studies:
less than 1 second for visual
“iconic”
3-4 seconds for auditory
“echoic”
Step 2: Input
goes to shortterm memory
where it is further
encoded
Step 3: Long-term memory
Step 3: Input goes to
long-term memory
where it lingers until
retrieved or can decay
So what’s wrong with this picture?

It neglects fact that some input bypasses conscious encoding of steps 1 & 2 and goes
straight to long-term storage AUTOMATICALLY!!

spatial—where things are in a room, routes to get to places

time—how much time has passed

frequency—how often you did, saw, or heard something during the day
Alan Baddeley (circa 2000) A better 3-box processing
model (upgrading from the Chevy to the Caddi!)
External
events
Step 1:
Sensory
memory
Step 2: Working Memory
(Central Executive “lives”
here, sifting and
winnowing incoming
stimuli, directs info. to
appropriate brain regions,
pulls info from long-term
storage to help process
new)
automatic encoding
Step 3: Longterm memory
Red arrow equals encoding; blue arrow equals retrieval
Effortful encoding takes first route; automatic bypasses straight to long-term!
Red arrow equals encoding; blue arrow equals retrieval
Alan Baddeley (circa 2000) A better 3-box processing
model (upgrading from the Chevy to the Caddi!)
External
events
Step 1:
Sensory
memory
Step 2: Working Memory
automatic encoding
Step 1: Brain receives “encodes” incoming fleeting sensory stimuli –
some goes the automatic route, other needs effort/attention
Events (stimuli) are encoded as:
•visual info.
•acoustic info.
•semantic info.
Step 3: Longterm memory
Red arrow equals encoding; blue arrow equals retrieval
Alan Baddeley (circa 2000) A better 3-box processing
model (upgrading from the Chevy to the Caddi!)
External
events
Step 1:
Sensory
memory
Step 2: Working Memory
Step 3: Longterm memory
automatic encoding
Step 2: Working Memory—where the magic of learning happens!
•Conscious activity, whatever you are thinking about
•Pulls together incoming stimuli PLUS information from long-term to be processed
together
•LIMITED capacity (Miller’s 7 +/- 2 rule) and duration (3-30 seconds)
Red arrow equals encoding; blue arrow equals retrieval
Alan Baddeley (circa 2000) A better 3-box processing model
(upgrading from the Chevy to the Caddi!)
External
events
Step 1:
Sensory
memory
Step 2: Working Memory
Step 3: Longterm memory
automatic encoding
Step 3: Ideas in working memory encoded to long-term -- Anything you remember 3
minutes after you have stopped consciously thinking about it is considered long-term
memory!!
Long-term memory
1. Storage locker for images, events, facts, words, etc (these things are NOT
stored in 1 single place, but rather throughout brain’s surface area AKA cortex)
2. Unlimited capacity and duration
3. For most people, NOT permanent memory-- some things have shorter “shelf
life” than others while others get LOST in the shelves or CORRUPTED over time
4. Case studies of unusual memory encoding and retrieval abilities:
a) Luria’s case study of “S”—defied Miller’s 7 +- 2 by memorizing 70 digits!!
b) eidetic/photographic memory
c) hyperthymestic (AKA autobiographical) memories Jill Price story (9 min)
5. Rehearsal and long-term potentiation (LTP) are key to making these
memories “stick”
Kinds of memories: Schachter’s golf experiment
1.
Explicit/declarative: Things we can talk about, consciously recall.
Processed by hippocampus and amygdala (inner brain structures)
A. Episodic—events in your life, things you did, witnessed, heard
about, or things that happened to you
B. Semantic—facts, knowledge, ideas
2. Implicit/nondeclarative--Processed by cerebellum (brain region at
base of brain)
A. Procedural—physical skills, mental skills, movement required to
do a task
B. Conditioned effects (reflexes, behaviors in response to
punishment or reward)
So what’s the difference between the Atkinson
and Shiffrin model and Baddeley’s model?

Working memory rather than “short-term” – implies
work is being consciously done

Baddeley’s adds automatic route
An alternative explanation of how memory
works:

Levels of processing

How much you remember depends upon:

how shallowly or deeply you process new concepts

how much, how many different ways you try to understand

accessing prior knowledge (positive transfer)

connecting the dots between concepts...
What makes some memories last longer or more
accurately in long-term memory than others?
Rehearsal!!!
1.
a)
Ebbinghaus’ retention curve, spaced rehearsal, forgetting curve
Use of mnemonic techniques
2.
a)
chunking
b)
peg words
c)
method of loci
d)
imagery
e)
acronyms, rhymes
What makes some memories last longer or more
accurately in long-term memory than others?
3. Use of organizational techniques
a) 3-column, color-coded notes
b) hierarchies, Thinking Maps
4. Depth of processing
5. Recall/access/use information often
6. Positive transfer—old info. may make it easier to learn new that is similar
7. “Flashbulb memories” – episodes accompanied by high levels of arousal
(stressful) can be “seared” into brain due to:
•
adrenal gland’s production of hormone epinephrine (adrenalin)
•
other stress chemicals produced brain’s amygdala during stressful event
Note: Even flashbulb memories are not infallible!
Aplysia Snail study

Snails were studied to find evidence of synaptic change during learning
 Synapse is space between brain cells (neurons)
 This space changes via long-term potentiation: the more often 2 neurons communicate,
the more “connected” they become = memory

How was study conducted?

Via classical conditioning (a tenet of the behaviorist perspective!! Notice how 2 perspectives merge
here: behaviorist and neuropsychology!)
1. Scientists repeatedly give mild electric shock to snail right after squirting it with water.
2. Electric shock produces reflex of withdrawing its gills
3. After repeated pairings, snail learns to associate water squirt with electric shock and will
withdraw gills when only water is squirted
4. A look at neurons before and after conditioning (learning), observed synaptic change
AND greater release of serotonin neurotransmitter (chemical language of neurons)
Question: In which part of the human brain should we see synaptic change if this
experiment were done on humans? (just assume we have gills!)
What impacts retrieval and retrieval accuracy?
In pairs, create an example of each of the following. You may use your notes.
 State-dependent memory
 Mood-congruent memory
 Rosy retrospection
 Priming
 Context cues
So what stops us from having infallible, hyperthymestic,
permanent, or eidetic memories of everything?
1. Childhood amnesia (start at 3:15 run to
9:37)
2. Encoding failure & error
3. Retrieval failure and error
4. Storage decay
Encoding failure & error
a) Eyewitness problems: “weapons effect”, race bias – Do
worksheet
b) Selective attention—consciously selecting the stimuli we attend
to with our senses and process in the working memory area of
our brains
a) Cocktail party effect: Example of how echoic memory can draw our
attention away from what we are listening to or watching
b) Choosing to attend to my voice during lecture or the voice in your
head planning your weekend or the feeling of pain or an itch on your
body
SO what? IF you don’t attend to the information coming into the
senses, it will NOT be encoded into working or long-term memory
UNLESS it is automatically encoded!!
Retrieval failure and error
A. Minsinformation effect (Elizabeth Loftus “stop sign”
experiment)
a) Children especially vulnerable!
b) phrasing of questions can lead mind to invent memories
B. Source amnesia –
a) President Reagan vivid, emotional recount on campaign trail about
WWII event – turned out to be scene from movie he had been in!
C. Interference
a) proactive and retroactive -(mnemonic: retro means “past”—new info. impeding access to old!)
Retrieval failure and error
5. Memory reconstruction not perfect
a) people can be misled due to suggestion (listen to Paul Ingram’s story)
b) rosy retrospection
6. Hypnosis induced “recovered” memories and those induced when
person under pressure or stress to produce answer NOT reliable
Storage decay
1. Lack of rehearsal
1. Brain injuries or damage
a) HM case study—anterograde amnesia (stop at 6:10)
b) Clive Wearing case study (part 1, video 10 – 10 min)
2. Disease --Alzheimer’s (video 19 -- 10 min.)—hippocampus starts to
die and plaque builds on cortex; brain cell’s that produce memory
enhancing chemicals die (we will learn more about this in unit on brain)
Storage decay
4. Prolonged exposure to stress hormones can corrupt pathways, shrink
hippocampus, block older memories (we will learn more about this in
unit on stress)
5. Can scientists force decay of unwanted memories? Video snip start at
2:30
(continue video to part 4, 3 minutes) As you watch, take bulleted
notes of facts about memory, how it forms, how it can be
“erased”