Human Information Processing Flashcards
Senses - Definition
A sense is a system, that consists of a sensory cell type that respond to a specific kind of physical energy and that correspond to a defined region within the brain where the signals are received and interpreted
Short-Term Sensory Storage (STSS)
- collecting information for processing
- holding information briefly while initial processing is going on
- filling in the blanks when stimulation is the intermittent
sensory systems can ‘store’ perceptions after the stimulus
SSTS does not need explicit attention, it works pre-attentive
SSTS is located in the brain
SSTS is not part of the conscious memory
SSTS is not short term memory
two most important types of short-term sensory memory:
- echoic memory (2-10 seconds after stimulus)
- iconic memory (0.5-1 second after stimulus)
Information Transmission
Human capability of information processing is limited –> it is not only of interest, how much information is presented to a human, but
- how much information is transmitted from stimulus to response
- capacity of the information channel
- how rapidly information is transmitted (bandwidth)
Perception
Raw sensory data must be interpreted and given meaning. This process is called perception
Perception generally happens
- automatically (little attention needed)
- fast (in contrast to cognitive processes)
driven by sensory inputs : bottom-up
driven by long-term memory : top-down
Attention
Attention is the cognitive process of selectively concentrating on one aspect of the environment while ignoring other things
Attention is as a crucial an element for cognitive processes as learning or task execution
types of attention
selective attention: willingly select focus
focused attention: respond to external events
divided attention: simultaneous focusing on different events
selective and focused attention
concentration on one stimulus source
- needed for e.g. perception or learning
- being too selective is referrred to as cognitive tunneling
- negative examples: selecting cues that stand out rather than useful ones
- difficult: humans have the tendency to be distracted
- important e.g. for directing attention to warning / error messages
- differences in errors between selective attention and focused attention: intentional selection of the wrong source vs. unintentional external influences
Divided Attention
- refer to the attention models
- limited attention capacity of humans
- important e.g. for layout of instruments in a cockpit
- differences in errors between focused attention and divided attention: some of our attention is directed to stimuli we do not wish to process vs. our limit to attend to all stimuli we wish to process
-> only a certain maximum of attention capacity can be divided to tasks
Vigilance
aspect of attention
detect signals over a long period of time,
the signals are intermittent unpredictable, infrequent, but
but it is known that they happen
vigilance paradigms
free-response paradigm:
- a target event occurs at any time
- non-events are not defined
- example: power plant monitor supervision
inspection paradigm:
- events occur at fairly regular intervals
- some are events, most are non-targets
- example: quality control
successive vigilance paradigm:
- target stimulus has to be remembered
- successive events have to be compared to the target stimulus
- example: detect if a color is darker than the initial target
simultaneous vigilance paradigm:
- all events/information needed for discrimination are presented at the same time
- example: compare many types of garment to a standard piece of fabric
sensory vigilance paradigm:
- signals represent changes in the auditory or visual intensity
- example color changes
cognitive vigilance paradigm:
- signals represent ‘information’: symbolic or alphanumeric stimuli
- example: proofreading a manuscript
Signal Detection Theory
- two discrete states: signal or noise (hit/miss or falseAlarm/correctRejection)
- two possible responses: yes or no (hit/falsAlarm or miss/CorrectRejection)
- 4 possible classifications –
SDT model assumes that there are two stages of information processing in the task of detection
- sensory evidence is aggregated concerning the presence or absence of the signal
- a decision is made about wether this evidence indicates a signal or not
Types of noise are
- internal (in our brain)
- external (in the data)
- internal response (in the observer’s brain)
SDT - sensitivity
Sensitivity is the resolution of the detection mechanism
refers to the separation of noise and signal distributions along the X axis
corresponds to the separation of the means of the two distributions
two major components of human memory
working memory
long-term memory
memory processes
- recall
- recognition
- chunking
- rehersal
- NOT: database
The brain
- makes of 2% of a person’s weight
- consumes 20% of body’s energy
- brain energy consumption is 10x the rate of the rest of the body per gram of tissue
- Average power consumption of a typical adult: 100 Watts
- brain: 20W
Working memory (WM)
- storage up to 30 seconds - after that the contents decay or are displaced
- rapid access: 70ms access time
- storage size: 3-4 ‘chunks’
- it is easy to overwrite the contents
- can store two different types of data at the same time: visual (viso-spacial sketchpad) and verbal (articulatory loop)
- to maintain the contents of working memory: rehearsal is needed
- to persistently store information from working memory: move it to long-term memory
Working memory types
Verbal: Phonological store
Visual: visualspacial sketchpad - stared often in the form of images
they operate in parallel, but there is only a restricted number of attention levels
Long-Term-Memory
- ‘unlimited’ in capacity
- lasts from a few minutes to life time
- slow access: 100ms access time
- mulit-modal memory
- smell as strong trigger
- sound as most efficient cue
Long-Term-Memory Types
episodic - serial memory of events
procedural - knowledge of how to do things
semantic - structured memory of facts, concepts, skills
semantic LTM derived from episodic LTM
LTM - forgetting
decay: information is lost gradually, but very slowly
interference:
* new information replaces old: retroactive interference
* old may interfere with new: proactive inhibition
affected by emotion - can subconsciously ‘choose’ to forget
LTM processes
- Encoding
- Retrieval
- Forgetting
- recall
- recognition
- rehersal (repeating information in working memory)
- chunking (grouping items into more meaningful units)
Icons
Icons often use a metaphor to recall an associated object or activity
It should be understandable, familiar, unambiguous, memorable, informative, distinct, attractive, legible, compact, coherent, extensible
Memory Design Guidelines (9)
M1: Organize information into a small number of “chunks”.
M2: Try to create short linear sequences of tasks.
M3: Use persistence, so do not flash important information onto the screen for brief time periods.
M4: Do not “overwrite” the contents of working memory by giving additional tasks to the user.
M5: Organize data fields to match user expectations or to organize user input (e.g. the automatic formatting of phone numbers)
M6: Provide reminders or warnings of the state the user has reached in an operation.
M7: Provide ongoing feedback on what is happening and/or what has just happened.
M8: The user interface should behave in consistent ways at all the times for all screens.
M9: Terminology, icons and the use of colour should be consistent between screens.
Decision making - automatic vs controlled decisions
automatic: fast
* little or no attention required
* learned reflexes or behaviour
* a long-term memory procedure is executed nearly automatically in response to the stimulus
controlled: slow
* attention required, typically conscious of thoughts
* interaction with working memory and long-term memory systems
