Storage Chapter 8, Lecture 3

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StorageChapter 8, Lecture 3
So, despite the brains vast storage
capacity, we do not store information as
libraries store their books, in discrete, precise
locations. - David Myers
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Storage Retaining Information
Storage is at the heart of memory. Three stores
of memory are shown below
Sensory Memory
Working Memory
Long-term Memory
Encoding
Events
Retrieval
Encoding
Retrieval
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Sensory Memory
Sensory Memory
Working Memory
Long-term Memory
Encoding
Events
Retrieval
Encoding
Retrieval
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Whole Report
Sperling (1960)
R G TF M QL Z S
Recall R T M Z (44 recall)
50 ms (1/20 second)
The exposure time for the stimulus is so
small that items cannot be rehearsed.
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Partial Report
S X TJ R SP K Y
Low Tone Medium Tone High Tone
Recall J R S (100 recall)
50 ms (1/20 second)
Sperling (1960) argued that sensory memory
capacity was larger than what was originally
thought.
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Time Delay
A D IN L VO G H
Low Tone Medium Tone High Tone
Recall N _ _ (33 recall)
Time Delay
50 ms (1/20 second)
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Sensory Memory
The longer the delay, the greater the memory loss.
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Sensory Memories
The duration of sensory memory varies for the
different senses.
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Working Memory
Sensory Memory
Working Memory
Long-term Memory
Encoding
Events
Retrieval
Encoding
Retrieval
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Working Memory

• Working memory, the new name for short-term
  memory, has a limited capacity (72) and a short
  duration (20 seconds).

Sir George Hamilton observed that he could
accurately remember up to 7 beans thrown on the
floor. If there were more beans, he guessed.
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Capacity
The Magical Number Seven, Plus or Minus Two Some
Limits on Our Capacity for Processing Information
(1956).
Ready?
M U T G I K T L R S Y P
You should be able to recall 72 letters.
George Miller
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Chunking
The capacity of the working memory may be
increased by chunking.

• F-B-I-T-W-A-C-I-A-I-B-M

FBI TWA CIA IBM 4 chunks
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Duration

• Peterson and Peterson (1959) measured the
  duration of working memory by manipulating
  rehearsal.

CHJ MKT HIJ 547
547 544 541
CH??
The duration of the working memory is about 20
sec.
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Working Memory Duration
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Long-Term Memory
Sensory Memory
Working Memory
Long-term Memory
Encoding
Events
Retrieval
Encoding
Retrieval
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Long-Term Memory

• Essentially unlimited capacity store.

R.J. Erwin/ Photo Researchers
The Clarks nutcracker can locate 6,000 caches
of buried pine seeds during winter and spring.
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Memory Feats
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Memory Stores
Feature Sensory Memory Working Memory LTM
Encoding Copy Phonemic Semantic
Capacity Unlimited 72 Chunks Very Large
Duration 0.25 sec. 20 sec. Years
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Storing Memories in the Brain

1. Loftus and Loftus (1980) reviewed previous
   research data showing, through brain stimulation,
   that memories were etched into the brain and
   found that only a handful of brain stimulated
   patients reported flashbacks.
2. Using rats, Lashley (1950) suggested that even
   after removing parts of the brain, the animals
   retain partial memory of the maze.

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Synaptic Changes

• In Aplysia, Kandel and Schwartz (1982) showed
  that serotonin release from neurons increased
  after conditioning.

Photo Scientific American
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Synaptic Changes

• Long-Term Potentiation (LTP) refers to synaptic
  enhancement after learning (Lynch, 2002). An
  increase in neurotransmitter release or receptors
  on the receiving neuron indicates strengthening
  of synapses.

Both Photos From N. Toni et al., Nature,
402, Nov. 25 1999. Courtesy of Dominique Muller
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Stress Hormones Memory

• Heightened emotions (stress-related or otherwise)
  make for stronger memories. Flashbulb memories
  are clear memories of emotionally significant
  moments or events

Scott Barbour/ Getty Images
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Beryl Benderly has described flashbulb memories
this way Its as if our nervous system takes a
multimedia snapshot of the sounds, sights,
smells, weather, emotional climate, even the body
postures we experience at certain moments.
In a sentence or two, write down your three most
vivid memories
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The percentage of Duke students who had
flashbulb recollections of each event
A car accident you were in or witnessed (85) Whe
n you first met your college roommate (82) Your
high school graduation (81) Your senior
prom (78) An early romantic
experience (77) A time you had to speak in
front of an audience (72) When you got your
admissions letter from college (65) The day
President Reagan was shot in Washington (52) Your
first flight (40) The moment you opened your
SAT scores (33) Your seventeenth
birthday (30) The last time you ate a holiday
dinner at home (23) Your first college
class (21) The first time your parents left
you alone at home (19) Your thirteenth
birthday (12)
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Storing Implicit Explicit Memories

• Explicit Memory refers to facts and experiences
  that one can consciously know and declare.
  Implicit memory involves learning an action while
  the individual does not know or declare what she
  knows.

p. 343
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Hippocampus
Hippocampus a neural center in the
limbic system that processes explicit memories.
Weidenfield Nicolson archives
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Anterograde Amnesia
After losing his hippocampus in surgery, patient
Henry M. (HM) remembered everything before the
operation but cannot make new memories. We call
this anterograde amnesia.

• Anterograde
• Amnesia
• (HM)

No New Memories
Memory Intact
Surgery
Different from retrograde amnesia, which is loss
of memory from before an event or injury.
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Implicit Memory
HM is unable to make new memories that
are declarative (explicit), but he can form
new memories that are procedural (implicit).

• HM learned the Tower of Hanoi (game) after his
  surgery. Each time he plays it, he is unable to
  remember the fact that he has already played the
  game.

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Cerebellum
Cerebellum a neural center in the hindbrain
that processes implicit memories.
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Homework
Read p.345-349
At any given moment, we can consciously process
only a very limited amount of information. -
David Myers