Memory
Chapter 6
The First Memory Research
• Herman Ebbinghaus: In 1800s, his own subject
• Nonsense Syllables: meaningless word-like
syllables (wug, gup, lix)
• Ebbinghaus: memorized lists to see how long
memory lasts
• Forgetting Curve: memory fades rapidly at first
and then levels off
• Overlearning: even if we know something,
additional study strengthens our memory of it
Information-Processing Model
A “computer-like model” describing how humans
encode, store, and retrieve information.
• encoding: getting information into memory
– type on keyboard = seeing or hearing
• storage: keeping information in memory
– save to disk = committing to memory
• retrieval: getting information out of memory
– open a file = bringing into consciousness
Sequence of Information Processing
The 3 Basic Stages of Memory
• 1. Sensory Register (store): receives
information thought the senses
• 2. Short Term Memory (STM): also
called “working memory” what we are
thinking about at the moment
• 3. Long Term Memory (LTM): stored
information
1. Sensory Register
(Sensory Store)
The Sensory Registers
• Sensory Registers: entry points for data
from the senses, (mainly visual/auditory)
• Icon: image in visual sensory store, lasts
less than a second (e.g., after you close your eyes)
• Echo: sound in auditory sensory store,
lasts several seconds (e.g., hearing a sentence)
• Attention: determines what sensory
information will be transferred to STM
Capacity of Visual Sensory Store
• Investigated by George Sperling using
his “Partial Report Procedure”
• The “icon” holds a tremendous amount
of information
• However, only a small amount can be
“attended to” and retained
• The rest fades away in a fraction of a
second
How Attention Works
• Donald Broadbent: investigated
attention in the auditory sensory store
• A different story was played to each
ear over headphones. People could
only really follow one.
• Broadbent’s Filter Theory: Broadbent
concluded attention is like a “switch”
that we turn on or off
The Cocktail Party Phenomenon
• You are at a party where people are
talking in small groups.
• From across the room you hear your
name mentioned and immediately your
“attention” shifts to that converstation
• According to Broadbent’s Filter
Theory, this should not happen
Attenuation Theory
• Anne Treissman suggests that attention is
NOT like a switch
• We turn the volume up or down on various
channels to meet our needs
• In reality, there are many channels, not just
two
• What we attend to (whether visual or auditory) is
passed along to “Short Term Memory” (STM)
2. Short Term Memory
(STM)
Capacity of STM
• 7 “bits” + or - 2 (as much information as can
be repeated in 1.5 to 2 seconds)
– a phone number is a good example.
• Chunking: grouping information into
meaningful units can increase the amount of
information held in STM.
Try to Memorize This
TRQENLPTQOINAN
What Can You Recall?
Try Memorizing This
JFKLHOLBJCIAFBI
What Can You Recall Now?
Encoding in STM
• We encode information in STM based on
its sound (phonologically) not its
meaning
• In STM recall tasks, people have a harder
time correctly recalling the word group
“mad, man, map, cap” (sound similar) than
the word group “pit, day, cow, bar” (don’t
sound similar)
Maintaining STM
• rote rehearsal: Most information is held
in STM by simply repeating it over and
over
• Like looking up a phone number and
repeating it until you dial it
• Some information may get to Long Term
Memory by rote rehearsal but it is not a
very efficient way of doing it
3. Long Term Memory
(LTM)
Encoding in LTM
• We saw that in STM information is
encoded mainly based on how it
sounds
• In LTM, information is stored based on
its “MEANING” and can be stored as a
visual image, a sound, a smell, etc.
The Serial Position Effect
• When learning a list of names our recall is
poorest for those in the middle of the list
(as opposed to those at the beginning or end of the list)
• Primacy effect: recall is good for words
early in the list because they had more of a
chance to be “rehearsed”
• Recency effect: recall is good for words at
the end of the list because they may still
be in STM
Maintaining Long Term Memory
• rote rehearsal: To hold information in STM, we
simply repeat it over and over BUT for LTM
this is not very effective (ex. Learn the musical staff)
– 1st space is F, 2nd space is A (with enough work, this
will be stored in LTM, but this is not very efficient)
• elaborative rehearsal: is the “Meaningful”
linking of new information to information
already in long-term memory
– FACE is a trick for remembering the spaces on the
musical “staff” (much more efficient).
Schemata (plural of schema)
• A “schema” is a framework that we
incorporate new memories into
• We might have schemas for driving,
attending class, etc.
• Imagine having to think about each step
needed to drive your car each time you
got in
• Schemas help us process daily experience
Priming
• Sometimes related information can
“prime” or “cue” us to remember
• You are taking a test and skipped
question 10 because you didn’t know it
• After reading question 31 you suddenly
know the answer to question 10
• Some word in question 31 “primed” your
memory for the topic of question 10
The Biology of Memory
• Memory Formation: a new memory is formed
when new synaptic connections are made
(new dendrites and axons are formed an
connected)
• Epinephrine and Cortisol: are two hormones
that stimulate the brain to form new memories
• Acetylcholine: a neurotransmitter, also plays
an important role in memory formation
• Hippocampus and Amygdala: are two brain
areas important in new memory formation
Biological Bases of Memory
Where are Memories Stored?
• Carl Lashley in the 1950s removed parts of
rats brains in a search for memory. He
could not identify any specific areas.
• Frontal and Temporal Lobes: we now know
that much of our “Semantic” and
“Episodic” memory is stored in these areas
Where are Memories Stored? (cont.)
• Cerebellum: much of our “Procedural”
memory is stored here. Recall, this area
is involved in coordination and
movement
• Amygdala: is important in formation and
storage of our “Emotional” memory
Forgetting
Loss of information from LTM
Retrograde Amnesia
• Brain trauma (e.g., being knocked out)
interrupts the transfer of information from
Short Term to Long Term memory.
• Information in STM just prior to the
trauma never gets to LTM and is
permanently lost
• This is “biological” and differs from
“psychogenic amnesia”(i.e., repressed
memories which are there but can’t be recalled)
Interference in Long Term Memory
• Retroactive interference: Newly
learned information interferes with the
retrieval of old (previously learned)
information.
• Proactive interference: Old
(previously learned) information
interferes with the retrieval of newly
learned information.
Retroactive and Proactive Interference
Situational Factors
• The situation or context in which you
remember and try to recall can make a
difference
• You regularly meet for Englidh class in
classroom A (old, dark, and musty) but your exam
is in classroom B (brand new, bright, and clean)
• You may do more poorly on your test in
classroom B because the “situational cues”
your brain has associated with the information
are not present!
State Dependent Memory
• Your physiological state may get stored
along with your memories as you study
(for example)
• Suppose you eat candy or drink coffee
as you study to “pick you up”
• You may recall better on a test if you
eat the same candy or drink coffee
Memory is “Reconstructive”
• memory is NOT like a snapshot
• we actually remember “parts” of events
and “fill in the blanks” as we recall them
• we may (unconsciously) change and
distort memories as we recall them
• many “repressed traumatic memories”
recalled in therapy never really happened!
Special Topics in Memory
• eidetic imagery: ability to reproduce unusually
sharp and detailed mental images of
something one has seen “photographic
memory”
• mnemonics: “tricks or techniques” that help
you remember (e.g., to learn the musical staff,
“face” and “every good by does fine”)
• Flashbulb Memory: “vivid” memory for a
highly emotional or important situation
Eyewitness Testimony
• Elizabeth Loftus: demontrated that
testimony can be easily distorted
• Two groups saw a film of an auto accident
• Group A was asked “How fast were the cars
going when they hit?”
• Group B was asked “How fast were the
cars going when they smashed?”
• Group B gave higher speed estimates!
Improving Your Memory
 practice
memory skills
 use elaborative vs. rote rehearsal
 make connections between new and
old information
 use mental imagery
 use mneumonics and retrieval cues