Download Short-Term Memory

Remembering and Judging
Remembering and Judging
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Memories as Types and Stages
How We Remember: Cues to Improving Memory
Accuracy and Inaccuracy in Memory and Cognition
Remembering and Judging
Memory
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The ability to store and retrieve
information over time
Cognition
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The processes of acquiring and using
knowledge
Remembering and Judging
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The cognitive approach became dominant in psychology in the 1960s.
– Psychology has remained largely cognitive ever since.
The cognitive approach was fueled by the advent of electronic computers.
– While there are many differences between computers and the human brain, the computer
has provided a useful model for understanding the brain.
Memories as Types and Stages
Memories as Types and Stages
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Learning Objectives
1.
Compare and contrast explicit and implicit memory, identifying the features that define
each.
2.
Explain the function and duration of eidetic and echoic memories.
3.
Summarize the capacities of short-term memory, and explain how working memory is
used to process information in it.
Memories as Types and Stages
Memories as Types and Stages
Explicit and Implicit Memory
Stages of Memory: Sensory, Short-Term, and LongTerm Memory
Stages of Memory: Sensory, Short-Term, and LongTerm Memory
sensory memory
• the brief storage of sensory information
• gives the brain time to process incoming sensations
short-term memory
• the place where small amounts of information can be kept for 20-30s
long-term memory
• memory storage that can hold information for days, months, and years
Sensory Memory
Iconic Memory
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Visual sensory memory
Duration is less than one second
Echoic Memory
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Auditory sensory memory
Duration is several seconds
Sensory Memory
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Sperling (1960) showed participants letter
displays for 1/20th of a second.
When he cued participants to report one of
the three rows of letters, they could do it,
even if the cue was given shortly after the
display had been removed.
The research demonstrated the existence
of iconic memory.
Short-Term Memory
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short-term memory – the place where small amounts of information can be kept for more than
a few seconds, but less than one minute
– working memory – the processes we use to make sense of, modify, interpret, and store
information in STM
• central executive – the part of working memory that directs attention and processing
Short-Term Memory
Duration
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About 20 seconds
The decay of information in STM can be
prevented by rehearsal.
– maintenance rehearsal – repeating
information mentally or out loud with
the goal of keeping it in memory
Capacity
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“Seven plus or minus two” pieces of
information
STM capacity can be expanded by chunking.
– chunking – organizing items into
groupings
Remembering and Judging
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Key Takeaways
– Memory refers to the ability to store and retrieve information over time.
– For some things our memory is very good, but our active cognitive processing of
information assures that memory is never an exact replica of what we have experienced.
– Explicit memory refers to experiences that can be intentionally and consciously
remembered, and it is measured using recall, recognition, and relearning. Explicit memory
includes episodic and semantic memories.
– Measures of relearning assess how much more quickly information is learned when it is
studied again after it has already been learned but then forgotten.
Remembering and Judging
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Key Takeaways, continued
– Implicit memory refers to the influence of experience on behavior, even if the individual is
not aware of those influences. Implicit memory includes procedural memory and priming.
– Information processing begins in sensory memory, moves to short-term memory, and
eventually moves to long-term memory.
– Maintenance rehearsal and chunking are used to keep information in short-term memory.
– The capacity of long-term memory is large, and there is no known limit to what we can
remember.
HOW WE REMEMBER
Cues to Improving Memory
How We Remember
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Learning Objectives:
1.
Label and review the principles of encoding, storage, and retrieval.
2.
Summarize the types of amnesia and their effects on memory.
3.
Describe how the context in which we learn information can influence our memory of
that information.
OPERANT CONDITIONING
encoding
retrieval
storage
How We Remember
How We Remember
How We Remember
Encoding and Storage: How Our Perceptions Become
memories
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Elaborative encoding
– Processing new information in ways that make it more meaningful or relevant
• self-reference effect
– Relating material to oneself or one’s experiences improves memory.
Elaboration and Memory
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Participants recalled the same words significantly better when they were
processed in relation to the self than when they were processed in other
ways.
Using the Contributions of Hermann Ebbinghaus to
Improve Your Memory
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Hermann Ebbinghaus found that memory for information drops off rapidly at first but then
levels off after time.
You should try to review the material that you have already studied right before you take an
exam – that way, you will be more likely to remember the material during the exam.
Using the Contributions of Hermann Ebbinghaus to
Improve Your Memory
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Ebbinghaus also examined the spacing effect and overlearning.
– spacing effect – Learning is better when the same amount of study is spread out over
periods of time (spaced practice) than when it occurs close together or at the same time
(massed practice).
– overlearning – continuing to study and practice even when one believes one has mastered
the material
• Overlearning improves memory performance.
Retrieval
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Retrieval
– The process of reactivating information that has been stored in memory
• tip-of-the-tongue phenomenon – we are certain that we know something we are
trying to recall, but we cannot quite come up with it; illustrates retrieval failure
Retrieval
Context-Dependent Learning
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An increase in retrieval when the external
situation in which information is learned
matches the situation in which it is
remembered
State-Dependent Learning
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Superior retrieval of memories when the
individual is in the same physiological or
psychological state as during encoding
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Godden and Baddeley (1975) tested the
memory of scuba divers to learn and
retrieve information in different contexts.
They found strong evidence for contextdependent learning.
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serial position effect – People better
retrieve items at the beginning and end of
a list than items in the middle.
primacy effect – People better retrieve
beginning items.
recency effect – People better retrieve end
items.
Retrieval
retroactive
interference
• Learning something new
impairs retrieval of
information learned earlier.
proactive interference
• Earlier earning impairs
encoding of information
we try to learn later.
The Structure of LTM: Categories, Prototypes, and
Schemas
Categories
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Networks of associated memories that have
features in common
– Associated concepts in a category are
connected through spreading
activation.
Some categories have defining features
true of all category members.
The prototype is the most typical category
member.
Schemas
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Patterns of knowledge in long-term memory
that help us organize information
– Stereotypes are schemas about social
groups.
The Biology of Memory
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long-term potentiation (LTP)
– the strengthening of synaptic connections between neurons as a result of frequent
stimulation
– consolidation – the period of time in which LTP occurs and in which memories are stored
The Biology of Memory
The Biology of Memory
retrograde amnesia
anterograde amnesia
• an inability to retrieve events
that occurred before a given
time
• the inability to transfer
information from short-term
into long-term memory
• New memories cannot be
formed.
The Biology of Memory
How We Remember
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Key Takeaways
– Information is better remembered when it is meaningfully elaborated.
– Hermann Ebbinghaus made important contributions to the study of learning, including
modeling the forgetting curve, and studying the spacing effect and the benefits of
overlearning.
– Context- and state-dependent learning, as well as primacy and recency effects, influence
long-term memory.
– Memories are stored in connected synapses through the process of long-term potentiation
(LTP). In addition to the cortex, other parts of the brain, including the hippocampus,
cerebellum, and the amygdala, are also important in memory.
How We Remember
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Key Takeaways, continued
– Damage to the brain may result in retrograde amnesia or anterograde amnesia. Case
studies of patients with amnesia can provide information about the brain structures
involved in different types of memory.
– Memory is influenced by chemicals including glutamate, serotonin, epinephrine, and
estrogen.
– Studies comparing memory enhancers with placebo drugs find very little evidence for their
effectiveness.
ACCURACY AND INACCURACY IN MEMORY AND
COGNITION
Accuracy and Inaccuracy in Memory and Cognition
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Learning Objectives:
1.
Outline the variables that can influence the accuracy of our memory for events.
2.
Explain how schemas can distort our memories.
3.
Describe the representativeness heuristic and the availability heuristic and explain how
they may lead to errors in judgment.
Accuracy and Inaccuracy in Memory and Cognition
Schematic Processing: Distortions Based on
Expectations
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Functional fixedness
– Schemas prevent people from using an
object in new and nontraditional
ways.
In the candle/tack-box problem, functional
fixedness may lead us to see the box as
only a box, not a potential candleholder.
Misinformation Effects: How Information That Comes
Later Can Distort Memory
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Misinformation effect
– errors in memory that occur when new information influences existing memories
Misinformation may not only distort our memories of events that actually occurred, but lead us
to falsely remember events that never happened.
Claims of ‘recovered’ memories of traumatic events (e.g., sexual abuse) may reflect the
implantation of false memories by therapists.
Misinformation Effects: How Information That Comes
Later Can Distort Memory
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Loftus and Palmer’s (1974) participants viewed a film of a traffic accident and
then answered a question about the accident.
The verb in the question was “hit,” “smashed,” or “contacted.”. The wording
of the question influenced the participants’ memory of the accident.
Overconfidence
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Overconfidence
– the tendency for people to be too certain about their ability to remember events and
make judgments
Eyewitnesses to crimes are often overconfident.
– There is a very small correlation between an eyewitness’ confidence and the accuracy of
the eyewitness’ memory.
Flashbulb memory
– a vivid and emotional memory of an event that people believe they remember very well
• an example might be one’s memory of the 9/11 attacks
– Flashbulb memories are less accurate than we believe them to be.
Heuristic Processing: Availability and
Representativeness
Availability
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Availability heuristic
– The tendency to make judgments
concerning an event’s frequency or
likelihood on the basis of the ease
with which the event can be retrieved
from memory
Representativeness
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Representativeness heuristic
– We base judgments on information
that seems to match our expectations,
and ignore potentially more relevant
statistical information.
Salience and Cognitive Accessibility
Salience
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Things that are salient attract our
attention, and may be better remembered
than things that are less salient.
– One example is a weapon in a crime
scene.
Cognitive Accessibility
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Knowledge that is activated in memory is
accessible and is more likely to drive
cognition and behavior than is less
accessible knowledge.
Counterfactual Thinking
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Counterfactual thinking
– The tendency to think about and experience events according to “what might have been”
• Silver medalists in the 1992 Summer Olympics were less happy than were the bronze
medalists because the silver medalists could imagine easily ‘what might have been’ –
winning the gold (Gilovich, 1995).
Accuracy and Inaccuracy in Memory and Cognition
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Key Takeaways
– Our memories fail in part due to inadequate encoding and storage, and in part due to the
inability to accurately retrieve stored information.
– The human brain is wired to develop and make use of social categories and schemas.
Schemas help us remember new information but may also lead us to falsely remember
things that never happened to us and to distort or misremember things that did.
– A variety of cognitive biases influence the accuracy of our judgments.