Transcript Long Term Memory – Event

Cognition
Rebecca W. Boren, Ph.D.
IEE 437/547
October 12, 2011
Cognition
What is a
Mental Model?
Cognition
What is a
Mental Model?
Memory for procedures
or how things work
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How to use an ATM
or ride a bicycle.
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Case Study: The Wrong
Mental Model Can Kill You
Kenneth Nemire
Proceedings of the Human Factors and
Ergonomics Society
51st Annual Meeting - 2007
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What is your mental model
of a roller coaster?
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Cognition
TOP GUN
An inverted roller coaster
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• Hanging roller coasters have
only been around for 20 years.
• They comprise 4% of the
world’s roller coasters.
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Research Results
• All of group 1 (118 students) and all of
group 2 (31 attorneys) drew pictures of
a sit-down roller coaster.
• Of the 19 people exiting the theme park (group 3), 76%
drew a picture of a sit-down roller coaster. This park had
a higher than usual number of inverted roller coasters –
75%.
Cognition involves
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Mental models
Thinking
Remembering
Forgetting
Learning
Attention
Schemata
Understanding
• Comprehension
• Situation awareness
• Time-sharing or multitasking
• Knowledge in the
Head
• Information
processing & storage
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Every day we process large
amounts of information.
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Cognition
What do you see?
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What do you see?
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Mental or cognitive resources
are of limited availability and
must be allocated. This
requires mental effort.
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Selective attention focuses on
some information and not on
other information.
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Attentional Capture
The understanding of information
processing is important to
designing alarms and displays.
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Attentional Capture
• Bottom up: when stimulus quality is high
bottom-up processing will dominate.
• Top down: we “sample” the world where we
expect to find information. How long we
attend to the signal depends on its value.
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Attentional Capture
Effort: we prefer to scan short distances
rather than long ones. We prefer to avoid
head movements to select information
sources. Why fatigued drivers fail to turn
their head and look behind them.
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Selective Attention
• Salience (conspicuous, unambiguous,
clear, obvious) features
• Effort
• Expectancy
• Value
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Perceptional Processes
• Extract meaning from information
processed by our senses.
• Cognition compares incoming information
with stored knowledge in order to
categorize.
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Three Perceptional Processes
• Bottom-up feature analysis.
• Top-down processing.
• Unitization (stimuli seen as a whole).
– Children see letters; adults see words.
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Do you see a letter imbedded
in the lines?
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What if we put the lines closer together?
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High expectations are based on
associations and context.
Turn the machine … when the
red light indicates failure.
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Understanding
Comprehension relies on
working memory unlike
perception.
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Working Memory
• Working memory is limited in capacity:
7 ± 2 chunks.
• Working memory is limited in duration:
7 to 70 seconds.
• Working memory is also called shortterm memory (STM).
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Working Memory
• A chunk is defined as one bit of
information.
• Examples: RXF is 3 chunks, while CUP is
a single chunk.
• NAT is 1 chunk because it is
pronounceable.
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Working Memory
• Create chunks by making spaces or
grouping: (480) 965-7258.
• Social security numbers are chunked.
xxx-xx-xxxx
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Working Memory
• Words are easier to remember than
numbers: 1-800-FLOWERS.
• Similarly sounding letters can be more
easily confused than letters that sound
different. DPZETG versus JTFWRU
• Group letters and numbers together, not
mixed: ABC123 rather than A1B2C3.
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Short-term Memory
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Working Memory
• Working memory is encoded in
three ways.
–Visual
–Phonetic
–Semantic
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Working Memory
• Working memory is encoded in
three ways.
–Visual DOG
–Phonetic “dawg”
–Semantic
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Working Memory
• Errors are usually acoustic rather than
visual.
• E may be recalled as D rather than F
• E sounds like D rather than F, although E
and F look more alike.
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Working Memory
• Avoid negatives. “Do not turn off the
equipment” may be heard as “Turn off
the equipment.”
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Working Memory
• Instruction should be followed by
action.
–“For billing, press 1”
–“I want roast beef, 3/4 of a pound”
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Working Memory
• Attention can be diverted.
–Example: cell phone use while
driving.
–Bathing a baby interrupted by the
telephone ringing.
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For information to be transferred from
STM to LTM, the person must direct
their attention and make some effort.
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End of Part 1
Next time we will talk about the
different memory systems and how
to transfer STM into LTM
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Long-term Memory
•Lasts a lifetime.
•Retrieval may pose a problem.
•Unlimited capacity.
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Long-term Memory
Two types of LTM:
•General Knowledge: schemata &
mental models
•Event memory: episodic & prospective
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Semantic Memory
• Semantic memory is part of LTM.
• Knowledge is organized into
semantic networks where
sections of the network contains
related pieces of information.
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Semantic Memory
• Associations are similar to
– Databases
– Networks
– Not like a filing cabinet
• Information is related in a
meaningful way.
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Long-term Memory
• Information in STM is transferred to LTM
by semantically encoding it.
• Reading the textbook over and over is not
enough. The material needs to be related
to past experience in some meaningful
way.
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Organization of LTM –
General Knowledge
• Information stored
in associative
• Memory we use for
networks.
daily activity is
semantic knowledge.
• Our knowledge is
stored in semantic
networks.
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The Brain is made up of
Neurons (HIGHLY
SPECIALIZED CELLS
THAT GENERATE AND
CONDUCT NERVE
IMPULSES).
http://www.nku.edu/~dempseyd/bio208pg8.htm
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The neurons interconnect
to send messages through
the network of brain cells.
How Memories Are Made, And Recalled
ScienceDaily (Sep. 16, 2008) — What makes a
memory? Single cells in the brain, for one thing.
The link below will take you to an article that
explains memory from a biological prospective.
http://www.sciencedaily.com/releases/2008
/09/080908101651.htm
Cognition
Organization of LTM –
General Knowledge
• Semantic memory is memory for concepts
and meaning of words.
• A schema is the entire knowledge
structure about a particular topic, e.g.
cups, college professors, vacations.
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Long-term Memory
• To recall more information, it must be
analyzed, compared, and related to past
knowledge.
• Retrieval is sometimes difficult.
• “Forgetting” is a failure of memory
retrieval.
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Long-term Memory
• Forgetting is due to
– Weak item strength
– Weak or few associations
– Interfering associations
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Long-term Memory
• “Remembering” is enhanced by frequent
rehearsal in STM and by making
meaningful associations with other
information.
• “Thinking” involves activation of taskrelevant material in working memory.
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Organization of LTM –
General Knowledge
• Scripts or mental models are memory for
knowledge of procedures (dynamic
schemata).
• Mental models generate a set of
expectancies.
• A large number of people having the same
mental model defines a population
stereotype.
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Organization of LTM –
General Knowledge
• Cognitive maps are mental representation
of spatial information.
• Examples:
– Layout of a classroom (POV)
– Geographical layout of a city
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Organization of LTM –
Event Memory
• Episodic memory for past events.
• Examples:
– Eyewitness testimony
– Birthdays and other special days
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Organization of LTM –
Event Memory
• Based on visual memory, but not a faithful
“video recording.”
• Memory may be biased
• Memory may be degraded
• Eyewitness testimony is generally
recognized as unreliable.
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Organization of LTM –
Event Memory
• Prospective memory for things that are
supposed to happen in the future.
• Failure of prospective memory is called
“absent-mindedness.”
Long Term Memory – General Knowledge
Semantic Network
Meaning of
concepts & things
Schema
Entire
knowledge
structure about
a particular topic
Mental Models &
Dynamic
Schemata
(Scripts)
Procedural
Cognitive Maps
&
Spatial memory
Long Term Memory – Event
Memory for Events
Episodic
Prospective
Memory for
past events
Memory for events
that are supposed to
happen in the future.
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Long-term Memory
Implications for Design
• Encourage regular use of information to
increase frequency and recency.
• Encourage verbalization of information
that is to be recalled.
• Standardize.
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Recall Task
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Long-term Memory
Implications for Design
• Use recognition rather than recall.
• Use memory aids. Knowledge in the
World. Cognitive artifacts. Checklists.
• Design information to be easily
remembered.
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Situation Awareness (SA)
Designers, researchers, and users employ
the concept of SA to characterize users’
awareness of the meaning of dynamic
changes in their environment.
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Lack of Situation Awareness
• A pilot suffers a
catastrophic
controlled-flight into
terrain.
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Lack of Situation Awareness
• Control room operators at the Three Mile
Island nuclear power plant lost SA when they
believed the water level in the plant to be too
high rather than too low.
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Situation Awareness (SA)
•Design easy-to-interpret displays of
dynamic systems.
•Tools for accident analysis.
•Training is important (especially for
attentional skills).
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Three Stages of Situation Awareness
• Perception & selective attention
• Understanding
• Prediction
All rely on STM and LTM.
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Time-sharing & Attention
Time-sharing is the ability to
perform more than one cognitive
task by attending to both at once
or by rapidly switching attention
back and forth between them
(divided attention).
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• Multi-tasking or time-sharing is
not doing two things at the
same time.
• It is switching back and forth.
• It is more difficult than most
people realize.
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Four major factors determine the
extent to which two or more
tasks can be time-shared.
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Multi-tasking
1. The degree to which one or more of
the tasks are trained to automaticity.
2. The skill in resource allocation.
3. The degree of shared resources.
4. The degree to which task elements
can become confused.
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What happens as we get older?
•Systems (vision, hearing, cognition)
deteriorate at different rates.
•Individuals undergo changes at different
rates.
•At what age should people stop driving
cars?
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•Older drivers have more accidents per
mile driven than younger drivers.
•One alarming story of the deaths of 10
people because of an 89-year old driver.
•It was not a visual problem, nor an
aging problem. It was a perceptual
problem.
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Useful Field of View (UFOV)
•UFOV related to attentional capture.
•Little correlation between driving safety
and visual acuity.
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Useful Field of View (UFOV)
•UFOV deficits occur more often in older
adults, but cut across all ages.
•Training can improve UVOF.
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Review of Memory Systems
Long Term Memory – General Knowledge
Semantic Network
Meaning of
concepts & things
Schema
Entire
knowledge
structure about
a particular topic
Mental Models &
Dynamic
Schemata
(Scripts)
Procedural
Cognitive Maps
&
Spatial memory
Long Term Memory – Event
Memory for Events
Episodic
Prospective
Memory for
past events
Memory for events
that are supposed to
happen in the future.
Cognition
Questions?