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Memory
Studying Memory
Building Memories: Encoding
Memory Storage
Retrieval: Getting Information Out
Forgetting
Memory Construction Errors
Improving Memory
Studying Memory
An information-processing model
Studying Memory
Memory
Persistence of learning over time through the
encoding, storage, and retrieval of information
Information-processing models
Used to help us think about how the brain forms and
retrieves memories
Encoding
Process of getting information into the memory
system
Storage
Process of retaining encoded information over time
Retrieval
Process of getting information out of memory storage
An Information-Processing Model
Atkinson and Shiffrin (1968): Three stages
1. We first record to-be-remembered information as a
fleeting sensory memory.
2. From there, we process information into short-term
memory, where we encode it through rehearsal.
3. Finally, information moves into long-term memory for
later retrieval.
Atkinson and Shiffrin’s classic three-step model helps us to think about how
memories are processed, but today’s researchers recognize other ways longterm memories form. For example, some information slips into
long-term memory via a “back door,” without our consciously attending to it
(automatic processing). And so much active processing occurs in the shortterm memory stage that many now prefer to call that stage working memory.
A MODIFIED THREE-STAGE
INFORMATION-PROCESSING MODEL OF MEMORY
Information-Processing
• Working memory
• Processes important, focused information
• Makes sense of new input
• Links with long-term memory
• Uses a central executive (Baddeley)
WORKING MEMORY
Alan Baddeley’s (2002) model of working memory, simplified here,
includes visual and auditory rehearsal of new information. Part of the
brain functions like a manager, a central executive focusing attention
and pulling information from long-term memory to help make sense
of new information.
What two new concepts update the classic
Atkinson-Shiffrin three-stage information
processing model?
What are two basic functions of working memory?
Building Memories: Encoding
Our two-track memory system
Automatic processing and implicit memories
Effortful processing and explicit memories
Building Memories: Encoding
Our two-track memory system
Explicit memories (declarative memories) of
conscious facts and experiences encoded through
conscious, effortful processing
Implicit memories (nondeclarative memories)that
form through automatic processes and bypass the
conscious encoding track
Building Memories: Encoding
Automatic processing and implicit memories
Implicit memories include automatic skills and
classically conditioned associations
Information is automatically processed about
Space
Time
Frequency
Effortful processing and explicit memories
With experience and practice, explicit memories
become automatic
Sensory memory
What is sensory
memory?
• First stage in forming
explicit memories
• Immediate, very brief
recording of sensory
information in the
memory system
• Iconic memory: Pictureimage memory
• Echoic memory: Sound
memory
TOTAL RECALL—BRIEFLY When
George Sperling (1960) flashed a
group of letters similar to this for onetwentieth of a second, people could
recall only about half the letters. But
when signaled to recall any one row
immediately after the letters had
disappeared, they could do so with
near-perfect accuracy.
Capacity of Short-Term and Working
Memory
Short-term memory
Activated memory that holds a few items briefly (such
as the seven digits of a phone number while dialing)
before the information is stored or forgotten
Working memory
Newer understanding of short-term memory that
stresses conscious, active processing of incoming
auditory and visual-spatial information, and of
information retrieved from long-term memory
Capacity of Short-Term and Working
Memory
Short-term memory
George Miller (1956)
Magical Number Seven: People can store about seven bits of
information (give or take two)
Baddeley and colleagues ( 1975)
Without distraction, about seven digits or about six letters or
five words
Working memory
Capacity varies by age and distractions at the time of
memory tasks
SHORT-TERM
MEMORY DECAY
Unless rehearsed,
verbal information
may be quickly
forgotten (From
Peterson &
Peterson, 1959; see
also Brown, 1958.)
Building Memories:
Encoding
Effortful processing
strategies
Chunking: Organizing
items into familiar,
manageable units; often
occurs automatically
Mnemonics: Memory
(From Hintzman, 1978.)
aids, especially techniques
that use vivid imagery and
organizational devices
Peg-word system
Building Memories: Encoding
Spaced study and self-assessment
Spacing effect: Encoding is more effective when it is
spread over time
Distributed practice: Produces better long-term recall
Massive practice: Produces speedy short term learning and
feelings of confidence
Repeated self-testing (testing effect) effect: Encoding
is very effective
Building Memories: Encoding
Making new information meaningful
Spaced practice is most effective when new
information is meaningful
Ebbinghaus
Estimated that, compared with learning nonsense
material, learning meaningful material required onetenth the effort
Which strategies are better for long term retention:
cramming and rereading material, or spreading out
learning over time and repeatedly testing yourself?
Memory Storage
Retaining information in the brain
Synaptic changes
Memory Storage: Retaining Information in the
Brain
Past research
Whole past is contained in memory—waiting to be
relived
Newer findings
Flashbacks during surgery are new creations of a
stressed brain
Information is not stored in a single, specific spot
Perception, language, emotions and more require
brain networks
Explicit- Memory
System: Hippocampus
and Frontal Lobes
Roger Harris / Science Source
The brain registers and
temporarily stores event
aspects in the
hippocampus
THE HIPPOCAMPUS Explicit
memories for facts and episodes are
processed in the hippocampus and fed
to other brain regions for storage.
Memories then migrate for
storage in memory
consolidation process
Right and left frontal lobes
store different information
The hippocampus and the
brain cortex display
rhythmic patterns of
activity during sleep
Retaining Information in the Brain
Implicit memory system: Cerebellum and basal
ganglia
The cerebellum plays an important role in forming and storing
memories created by classical conditioning
Memories of physical skills are also implicit memories
Basal ganglia help form memories for these skills
Infantile amnesia
Conscious memory of the first three years is blank
Command of language and a well-developed hippocampus are
needed
Review Key Memory Structures in the Brain
Frontal lobes and hippocampus: explicit memory formation
Cerebellum and basal ganglia: implicit memory formation
Amygdala: emotion-related memory formation
Which parts of the brain are important for implicit
memory processing, and which parts play a key
role in explicit memory processing?
Your friend has experienced brain damage in an
accident. He can’t remember anything told to him
during a conversation. What’s going on here?
Retaining Information in the Brain
Excitement or stress trigger hormone production
and provoke the amygdala to engage memory
Emotions often persist with or without conscious
awareness
Flashback memories occur via emotiontriggered hormonal changes and rehearsal
Synaptic Changes
Long-term potentiation (LTP)
Increase in a synapse’s firing potential
After LTP, the brain will not erase memories
Believed to be a neural basis for learning and
memory
Kandel and Schwartz (1982)
Pinpointed changes in sea slugs’ neural connections
With learning more serotonin is released and cell
efficiency increased—number of synapses increase
Our Two Memory Systems
Which brain area responds to stress hormones by
helping to create stronger memories?
The neural basis for learning and memory, found
at the synapses in the brain’s memory
connections, results from brief, rapid stimulation. It
is called ________.
Retrieval: Getting Information Out
Measuring retention
Retrieval cues
Retrieval: Getting Information Out
Three types of evidence indicate memory
retention
Recall
Recognition
Relearning
EBBINGHAUS’
RETENTION CURVE
The more times
Ebbinghaus practiced a
list of nonsense
syllables on day 1, the
less practice he needed
to relearn it on day 2
Speed of relearning is
one way to measure
whether something was
learned and retained
(From Baddeley, 1982.)
Multiple-choice questions test our
a.
recall.
c. relearning.
b.
recognition.
d. sensory memory.
Fill-in-the blank questions test our ________.
If you want to be sure to remember what you’re learning for
an upcoming test, would it be better to use recall or
recognition to check your memory? Why?
Retrieval: Getting Information Out
Memory retrieval
Memories are held in storage by a web of
associations
Retrieval cues serve as anchor points for pathways to
memories suspended in this web
Priming
Activation, often unconsciously, of particular
associations in memory
Retrieval Cues
PRIMING—AWAKENING
ASSOCIATIONS
After seeing or hearing
rabbit, we are later more
likely to spell the spoken
word as h-a-r-e
Associations unconsciously
activate related associations
This process is called
priming (Adapted from
Bower, 1986.)
Retrieval Cues
Context effects
Priming memory is often helped by returning to the
context of the experience
State-dependent memory
There is a tendency to recall events consistent with
current good or bad mood (mood-congruent memory)
Serial position effect
There is a tendency to recall best the last and first
items in a list
Alexis Rosenfeld / Science Source
The Effects of Context on Memory
Words heard underwater were best recalled underwater; words
heard on land were best recalled on land. (Adapted from Godden
& Baddeley, 1975.)
What is priming?
When we are tested immediately after viewing a
list of words, we tend to recall the first and last
items best, which is known as the ________ effect.
Forgetting
Forgetting and the two-track mind
Encoding failure
Storage decay
Retrieval failure
Forgetting and the
Two-track Mind
John Gibbins/ZUMApress/Newscom
Humans have two distinct
memory systems, controlled
by different parts of the brain
STUDYING A FAMOUS BRAIN Jacopo
Annese and of California are preserving
Henry Molaison’s brain for the benefit of
future generations. Their careful work will
result in a freely available online
brain atlas.
Forgetting has several
causes
Encoding failure
Storage decay
Retrieval failure
Interference
Motivated forgetting
Let’s look more closely at these
causes.
Forgetting: Encoding and Storage Decay
Encoding failure
Age: Encoding lag is linked to age-related memory
decline
Attention: Failure to notice or encode contributes to
memory failure
Storage decay
Course of forgetting is initially rapid, and then levels
off with time
Physical change in the brain occur as memory forms
(memory trace)
We cannot remember what we have not encoded.
FORGETTING AS ENCODING FAILURE
Bill Aron / Photo Edit
The Forgetting Curve For Spanish Learned
In School
Compared with others just completing a Spanish language-learning course,
people 3 years out of the course remember much less. Compared with the 3year group, however, those who studied Spanish even longer ago did not forget
much more. (Adapted from Bahrick, 1984.)
Forgetting: Retrieval Failure
Reason for failure
Events and memories are not available because they
were never acquired
Memories have been discarded due to stored
memory decay
Insufficient information to access memories make
these out of reach
Reason for failure
• Events and memories are not available because they
were never acquired
• Memories have been discarded due to stored memory
decay
• Insufficient information to access memories make
these out of reach
RETRIEVAL FAILURE
Forgetting
Interference
Proactive: Occurs when older memory makes it more
difficult to remember new information
Retroactive: Occurs when new learning disrupts memory
for older information
Motivated forgetting
Freud: Repressed memories protect self-concept and
minimize anxiety
Today: Attempts to forget are more likely when information
is neutral, not emotional
RETROACTIVE
INTERFERENCE
People forgot more when they
stayed awake and experienced
other new material. (From
Jenkins & Dallenbach, 1924.)
WHEN DO WE FORGET?
• Forgetting can occur at any
memory stage
• As we process information,
we filter, alter, or lose
much of it
What are three ways we forget, and how does
each of these happen?
Memory Construction Errors
Misinformation and imagination effects
Source amnesia
Recognizing false memories
Children’s eyewitness recall
Repressed or constructed memories of abuse?
Memory Construction Errors
Memory is not exact
Proactive interference: Disruptive effect of
prior learning on the recall of new information
Retroactive interference: Disruptive effect of
new learning on the recall of old information
7-17 How do misinformation, imagination, and source amnesia influence our
memory construction? How do we decide whether a memory is real or false?
Memory Construction Errors
Misinformation and imagination effects
Misinformation effect occurs when a memory has
been corrupted by misleading information
Imagination effect occurs when repeatedly imaging
fake actions and events can create false memories
MEMORY CONSTRUCTION
In this experiment, people viewed a film of a car accident
(left). Those who later were asked a leading question recalled a
more serious accident than they had witnessed. (From Loftus, 1979.)
Memory Construction Errors
Source amnesia
Involves faulty memory for how, when, or where
information was learned or imagined
Déjà vu
Sense that “I’ve experienced this before.”
Suggests cues from the current situation may
unconsciously trigger retrieval of an earlier
experience
Recognizing False Memories
Children’s eyewitness recall
Ceci and Bruck
Researchers studied the effect of suggestive interviewing
techniques
58 percent of preschoolers produced false stories about one
or more unexperienced events
Children often accurately recall events and actors
Neutral person
Nonleading questions soon after event containing words
children can understand
Repressed or Constructed Memories of
Abuse?
Challenges related to adult recognition of
childhood abuse:
People do not believe abuse survivors
Innocent people are falsely accused
Repressed or Constructed Memories of
Abuse?
Those committed to protecting abused children and
those committed to protecting wrongly accused
adults have agreed on the following:
Sexual abuse happens
Injustice happens
Forgetting happens
Recovered memories are commonplace
Memories of things happening before age 3 are unreliable
Memories “recovered” under hypnosis are especially
unreliable
Memories, whether real or false, can be emotionally
upsetting
Improving Memory
What do you do to improve your memory
and increase your success in this course?