MEMORY
Chapter 7, 19 (Bernstein), pages 237-277, 770-773
THE NATURE OF MEMORY
Basic Memory Processes
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The process of putting information into memory is called ENCODING.
Sensory info is put into memory codes (mental representations of physical
stimuli).
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ACOUSTIC ENCODING information as sequences of sounds
VISUAL ENCODING information in the form of a picture
SEMANTIC ENCODING the general meaning of information
Holding information in memory over time is called STORAGE.
RETRIEVAL pulling info out of memory and into consciousness after it’s been
stored
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Recall retrieving info without any cues to help
Recognition retrieving info with the aid of cues
THE NATURE OF MEMORY
Types of Memory
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At least 3 types of memory exist, each named for the type of information it
handles.
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EPISODIC MEMORY any memory of a specific event that happened while
you were present
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SEMANTIC MEMORY memory which contains generalized knowledge of
the world that does not involve memory of a specific event
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e.g., your 13th birthday party, when you found out a close relative died,
your first day of school at South Warren HS
e.g., George W. Bush, the relative location of Canada, things to do in
New York City
PROCEDURAL MEMORY memory of how to do things, of how to perform
physical tasks (often difficult to explain in words; easier to demonstrate)
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e.g., tying shoes, working an algebraic equation, performing surgery
THE NATURE OF MEMORY
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Explicit and Implicit Memory
EXPLICIT MEMORY used when you
consciously and deliberately try to
remember something
• e.g., answering test questions, game
shows, conversation
• IMPLICIT MEMORY
the unintentional
recognition and influence of prior
experiences
• e.g., sports skills, reading, eating
THE NATURE OF MEMORY
Models of Memory
•There are currently five models that attempt to explain
memory.
1. INFORMATION PROCESSING MODEL
2. LEVELS-OF-PROCESSING MODEL
3. TRANSFER-APPROPRIATE PROCESSING
MODEL
4. PARALLEL DISTRIBUTED PROCESSING
MODELS
5. MULTIPLE MEMORY SYSTEMS
THE NATURE OF MEMORY
Models of Memory
•INFORMATION PROCESSING MODEL
•there are three stages of mental processing required
before information can be firmly embedded in memory
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SENSORY MEMORY
SHORT-TERM MEMORY
LONG-TERM MEMORY
THE NATURE OF MEMORY
Models of Memory
•LEVELS-OF-PROCESSING MODEL
•states that WHAT and HOW well we remember are a
function of how deeply information is processed or
encoded when first experienced
•MAINTENANCE REHEARSAL
repeating and item
over and over
•ELABORATIVE REHEARSAL
building associations
or linkages between new and old information; requires
deeper level processing and results in stronger
memories
THE NATURE OF MEMORY
Models of Memory
•TRANSFER-APPROPRIATE PROCESSING MODEL
•suggests the most important memory determinant is
how well the processes involved during RETRIEVAL
match the way the information was originally encoded
THE NATURE OF MEMORY
Models of Memory
•PARALLEL DISTRIBUTED PROCESSING MODELS
•suggests new facts are integrated with existing knowledge
or memories
•changes our overall knowledge base and alters our
understanding of the world and how it operates
•each unit of knowledge connected to every other unit of
knowledge
•allows us to quickly and efficiently draw inferences and
generalizations about new and old info
THE NATURE OF MEMORY
Models of Memory
•MULTIPLE MEMORY SYSTEMS
•suggests the brain contains several separate memory
systems
•each system resides in a different area of the brain
•each area serves different purposes
STORING NEW
MEMORIES
Sensory Memory
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SENSORY MEMORY holds information from all the senses.
This information is held in SENSORY REGISTERS for a fraction of a
second--just long enough for it to be processed further, if desired.
Sensory memory allows us to experience a constant flow of information.
SELECTIVE ATTENTION focuses mental processing on only part of the
stimulus field, controlling what information is processed further.
e.g., (of sensory information)
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STORING NEW
Short-Term MEMORIES
Memory and Working Memory
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SHORT-TERM MEMORY (STM) stores limited amounts of information for
a limited amount of time (around 18 seconds unless rehearsed according
to the Brown-Peterson procedure).
STM is a component or WORKING MEMORY--that part of our memory
which allows us to work with or manipulate the information in the STM.
Working memory has at least two components:
1. MAINTENANCE (holding information in STM)
2. MANIPULATION (working on that information)
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e.g., (of using working
memory)__________________________________________________
STORING NEW
Short-Term MEMORIES
Memory and Working Memory
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Encoding in Short-Term Memory
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Acoustic encoding (by sound) is the dominant form.
Visual codes tend to decay faster than acoustic codes.
Evidence exists to suggest there is also kinesthetic encoding
(encoding by physical movement)
e.g., (of each type of encoding)
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STORING NEW
Short-Term MEMORIES
Memory and Working Memory
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Storage Capacity of Short-Term Memory
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IMMEDIATE MEMORY SPAN is the number of imtes you can recall
perfectly after one presentation of a stimulus. This “magic number” is
usually seven +/- two (five to nine) items or groupings of information.
Groupings of information are called CHUNKS.
STM can be noticeably improved by chunking--creating bigger and
bigger chunks, or groups, of information.
e.g., (of “practical” chunking)
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STORING NEW
MEMORIES
Long-Term
Memory
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Long-Term Memory (LTM) has the encoding and storage capabilities to
produce memories that last a lifetime.
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ENCODING
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Some information is encoded in LTM without conscious effort.
Most encoding is the result of elaborate, conscious processing
and usually involves semantic encoding (which can result in
problems if recall of specifics is important).
Visual codes are also used to encode long-term memories.
Dual coding theory states information is remembered better if
both semantic and visual codes are used.
e.g., (of both types of
encoding)_____________________________________________
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STORING NEW
MEMORIES
Long-Term
Memory
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Long-Term Memory (LTM) has the encoding and storage capabilities to
produce memories that last a lifetime.
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STORAGE CAPACITY OF LTM
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Most theorists believe there’s no limit to the amount of info that
can be stored in long-term memory.
Most theorists also realize our memories can be quite distorted.
Distortion can even occur in flashbulb memories--vivid
recollections of personally significant events.
e.g., (of flashbulb memories)
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STORING NEW
MEMORIES
Distinguishing
Between STM and LTM
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IS THERE A DIFFERENCE BETWEEN SHORT-TERM AND LONG-TERM
MEMORY?
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Psychologists disagree about the differences between STM and LTM.
Some believe they are the same; that what is referred to as short-term
memory is part of long-term memory that is being used at a particular
moment in time.
Other psychologists claim STM and LTM obey different laws.
EXPERIMENTS ON RECALL
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Serial position curves show a tendency to recall both the first and last
parts of a list--primacy and recency effects, respectively--when
memory is immediately tested.
It has been proposed that primacy effects reflect LTM and recency
effects are due to STM.
RETRIEVING MEMORIES
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Retrieval is the ability to bring a memory into consciousness.
RETRIEVAL CUES AND ENCODING SPECIFICITY
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RETRIEVAL CUES--stimuli that help people retrieve information
from LTM.
According to the encoding specificity principle, these cues are
more efficient when they are related to the meaning of the
originally encoded information.
e.g., (of efficient retrieval cues)
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RETRIEVING MEMORIES
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CONTEXT AND STATE DEPENDENCE
CONTEXT DEPENDENT MEMORY--when memory is helped or
hindered by an environment that is the same or similar to the one where
the material was originally learned
e.g., (of context dependent memory)
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STATE DEPENDENT MEMORY--when a person’s internal state can aid
or hamper retrieval
e.g., (of state dependent memory)
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In the mood congruency effect, recall is facilitated if a person’s
emotional state is similar in tone to the information being recalled.
People tend to remember more positive events when they are in a
positive mood.
e.g., (of mood congruency effect)
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RETRIEVING MEMORIES
RETRIEVAL FROM SEMANTIC MEMORY
Semantic network theory
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suggests semantic memories represented in a dense network of
association
info retrieved through a spreading activation process (e.g., Thinking
about concept X spreads neural activity to all other features,
attributes,and concepts associated with concept X.)
stronger association more quickly retrieved
result of this network organization--we both retrieve facts we have
learned AND also make conclusions about other facts
e.g., (of spreading
activation)________________________________________________
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RETRIEVING MEMORIES
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RETRIEVAL FROM SEMANTIC MEMORY
Retrieving Incomplete Knowledge
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when we retrieve some features and attributes of a concept but cannot
access the entire concept
Tip-of-the-tongue phenomenon when people cannot recall a
particular word but can recall many features of it--its first letter, number
of syllables, etc.
Feeling-of-knowing experience when people cannot recall an answer
but can retrieve enough info to determine whether the answer is
actually stored in their memory and able to be correctly recognized
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RETRIEVING MEMORIES
CONSTRUCTING MEMORIES
People construct memories by using their existing knowledge to organize new
information and to fill in gaps in information that is being encoded or retrieved.
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Relating Semantic and Episodic Memories (Parallel Distributed
Processing Models): PDP models offer one explanation for how
semantic and episodic info become integrated in constructive memories
because they represent knowledge as LINKS in a network of
associations.
PDP networks can produce spontaneous generalizations,
unsubstantiated assumptions that are based on limited or biased
information.
SCHEMAS are representations of categories of objects, events, and
people.
According to PDP models, the generalized knowledge contained in
schemas provides the basis for making inferences about incoming
information during the encoding stage.
RETRIEVING MEMORIES
inkages: Memory, Perception, and Eyewitness Testimon
• Factors influencing eyewitnesses’ ability to recall information during courtroom
testimony
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1) They can only remember what they perceive and perceive only what
they pay attention to.
2) The semantic encoding typical of LTM can cause the loss of certain
important details.
3) New info in questions AND how questions are asked can alter a
witness’s memory.
4) Objects or events not witnessed but mentioned after the fact many be
incorporated into
memories (“misinformation effect”) and can
occur for a number of reasons:
New info may make it harder to retrieve the original memory.
New info may be integrated into the original memory making it impossible to
distinguish the new info from the original memory.
If a respected person says an object was there or an event occurred, witnesses
might believe this must be true.
RETRIEVING MEMORIES
inkages: Memory, Perception, and Eyewitness Testimon
part 2
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Jurors tend to judge a witness as believable based on how the witness presents
evidence, not just on what the witness says.
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1) Jurors are more likely to believe witnesses who give very detailed accounts,
even if those accounts are inaccurate.
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2) Jurors are more likely to believe witnesses who are very confident,
but research suggests that, on average, more confident witnesses are
not more accurate. (Inflated confidence may stem from repeated
exposure and recall of misinformation.)
Eyewitness ID of criminals is more accurate when mug shots are viewed one at
a time OR when witnesses are told the alleged perpetrator might not be included in
the lineup.
FORGETTING
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HOW DO WE FORGET?
METHOD OF SAVING Hermann Ebbinghaus’s method which involves
computing the difference between the number of trials needed to learn
something and the number of trials needed to relearn it again after some time
has passed.
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This difference is called savings.
Savings decline and forgetting increases as time passes.
The most dramatic drop in what is retained in LTM occurs during the
first nine hours, especially the first two.
The shape of the forgetting curve (depicting how much and when
people forget) stays relatively constant regardless of the type of info
learned. After the intial strong drop in memory, the decrease moderates
over time.
Savings in LTM can be very long-lasting, retained often for decades.
FORGETTING
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WHY DO WE FORGET?
DECAY the gradual disappearance of the mental representation of a stimulus.
Decay is prominent in forgetting in STM.
INTERFERENCE a process through which the stoage or retrieval of information
is impaired by the presence of other information.
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It may occur because one piece of information displaces other info or
because one piece of info makes storing or recalling other info more difficult.
It occurs in both STM and LTM but is more directly tied to forgetting in LTM.
Retroactive interference learning new info interferes w/ recalling old info
Proactive interference older info interferes w/ learning or recalling new info
Some suggest all forgetting from LTM is due to some form of retrieval failure
(interference) rather than decay. However, no one knows for sure why we forget.
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BIOLOGICAL BASES OF
MEMORY
The Biochemistry of Memory
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Brain cells change as memories are formed and stored.
One early theory (Donald Hebb, 1949) suggested that each memory is
represented by a group of interconnected neurons called a cell assembly. This is
the basis for the expanded, modern understanding of the biochemistry of memory.
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The formation and storage of new memories are associated with changes in
synapses:
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When new synapses are formed, communication at existing synapses is altered.
Repeated signals across a synapse increase the number of spines on the
receiving dendrite, which appears to enhance memory capabilities.
long-term potentiation synapses become “sensitized” to be more responsive to
future stimulation (due to increased frequency of use)
long-term depression synaptic connections become weakened (lack of use)
The neurotransmitters glutamate and acetylcholine play important roles in
memory.
BIOLOGICAL BASES OF
MEMORY
Brain Structures and Memory
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Memory involves both
specialized regions for
various types of memory
formation and widespread
areas for storage.
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The hippocampus,
nearby parts of the
cortex, and the
thalamus are important
in the formation of new
memories.
Other aspects of
memory (such as
sights and sounds
associated with certain
events) are stored if
different parts of the
cerebral cortex.
A little more info on memory and brain structures...
The hippocampus deals with directions and the long term memory .
The amygdala incorporates memories and emotions. The cerebral
cortex (also known as the outer layer of the brain) stores the long
term memory in many brain regions depending on the information
types, namely the language, sensory input, problem solving,
decision making, etc.
BIOLOGICAL BASES OF
MEMORY
Brain Structures and Memory (cont.)
• The Impact of Brain Damage
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anterograde amnesia
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damage to hippocampus; loss of memory of events occurring AFTER the
injury; cannot transfer new info from STM to LTM; cannot form explicit
memories; implicit, procedural, and working memory remain intact;
THUS...hippocampus appears to be crucial in the formation of episodic
memories while other types of memories are controlled by other brain areas
retrograde amnesia
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loss of memory of events that occurred BEFORE the injury; many patients
regain most memories; may never remember last few seconds before injury;
short-term memories never transferred to LTM; cases involving amnesia for
hours or minutes before the trauma suggest that as memories move from
STM to LTM, they are initially unstable and vulnerable to disruption; may take
minutes, hours, or days before these transitioning memories are fully
solidified, or consolidated
BIOLOGICAL BASES OF
MEMORY
Brain Structures and Memory (cont. again)
• Multiple Storage Areas
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Memories are likely stored in/around the cortex. Certain areas store specific
aspects of a remembered event, but many brain regions are involved in
experiencing the whole event.
Memory problems observed due to damage to various brain areas are consistent
with the view that STM and LTM are distinct systems.
Research on memory retrieval:
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Imaging studies show the hippocampus and regions of the parietal cortex and
prefrontal cortex are active during memory retrieval.
Retrieving memories of certain experiences may also activate sensory and
motor regions of the brain that may have been involved during the event itself.
Research suggests that when memories are recalled, they may have to be
stored again or reconsolidated. During this process the memory may be
open to distortion.
APPLICATIONS OF MEMORY RESEARCH
Improving Your Memory
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The best strategies for improving memory are based on the elaboration of
incoming information and linking new information to what is already known.
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Mnemonics strategies for placing info into an organized context to remember it
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Acronyms involve putting just the first letters of each of a list of things to be
remembered into one easily recalled word or phrase.
e.g., ____________________________________________________
Verbal organization is the basis for many mnemonic devices such as stories
or rhymes.
e.g., ____________________________________________________
The method of loci associates well-known locations with info to be
remembered.
e.g., ____________________________________________________
APPLICATIONS OF MEMORY RESEARCH
Improving Your Memory
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Create a context, such as an outline, for organizing info.
Use elaborate rehearsal with new info.
Use distributed practice rather than massed practice.
Practice retrieval of learned info by repeated self-testing (e.g., flashcards)
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Reading a Textbook
Successful students monitor their understanding of their reading, reread difficult sections, and review
periodically.
Check for understanding before going on.
To increase depth of info processing, use the PQ4R method (preview, question, read, reflect, recite, review)
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Guidelines for More Effective Studying
Lecture Notes
Focus on expressing major ideas in relatively few words, draw connections with other material, and
summarize main pts.
Review notes ASAP after lecture to fill in missing details and create flashcards for key terms.
When studying for an exam, create a detailed outline of notes and think about how various points are related.
APPLICATIONS OF MEMORY RESEARCH
Design for Memory
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The scientific study of memory has influenced the design of electronic and
mechanical devices that play important roles in our lives.
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Common examples include:
placing the least-likely-to-be-remembered instructions on a device
using words for toll-free numbers to help people chunk information
Other examples:
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