Human Information Processing

Question 1

Three-Stage Model of Information Processing

Answer 1

(Stimulus) –> Perception –> Cognition –> Action –> (Response)

Question 2

Three-Stage Model: Perceptual Stage

Answer 2

• Processes that operate from the stimulation of the sensory organs - Some can occur without the person aware of the processes involved in detection, discrimination, and identification - The ability to extract information from the stimulus depends on the quality of the sensory input

Question 3

Three-Stage Model: Cognitive Stage

Answer 3

• Identifies or classifies the stimulus - Begins to operate to determine an appropriate response - May include retrieval of information from memory, comparison of displayed items, comparison of items and memory, arithmetic operations, and decision making - Cognitive limitations (amount of cognitive resources) can cause human error

Question 4

Three-Stage Model: Action Stage

Answer 4

• An overt response (if required) is selected, programmed and executed

1. First, it chooses the most appropriate response
2. Then the response is translated into a set of neuromuscular commands
3. Then the commands are executed

Question 5

Three-Stage Model: Cognitive Stage
[Memory]

Answer 5

Sensory Memory –> Working Memory –> Long-Term Memory

Question 6

Sensory Memory

Answer 6

• Sensory memory acts as a butter for stimulie received through the senses and is constantly being overwritten by new information
• A sensory memory exists for each sensory channel:
• Iconic memory for visual stimuli
• Echoic memory for auditory stimuli
• Haptic memory for touch
• Information is passed **from sensory memory into working memory by attention **

Question 7

Working Memory

Answer 7

• Working memory (WM) is a temporary memory sstem that you use in order to help you do other complicated cognitive tasks
• Working memory is fragile and contents must be maintained
• get distracted by something and the contents of your working memory are lost
• rehearsal can help maintain the contents of working memory (at least until you stop rehearsing)
• Components
• Phonological loop: stores the sound of language
• Visuo-Spatial sketchpad: stores visual and spatial information
• Information must be encoded in order to be stored in long-term memory for future retrieval

Question 8

The Working Memory Model

Answer 8

Central Executive

• Phonological Loop
• Articulatory Loop
• Acoustic Store
• Episodic Buffer
• Visuo-Spatial Sketchpad

Question 9

Processing Errors:
Data-Limited Processing

Answer 9

The information input to a stage is degraded or imperfect (i.e. a visual stimulus is only briefly flashed or speech signals are presented ina noisy environment)

Question 10

Processing Errors:
Resource-Limited Processing

Answer 10

The system is not powerful enough to perform the operations required for a task efficiently (memory resorces required to remember a long-distance phone number until it is dialed)

Question 11

Psychological Representation of the Physical World

Answer 11

To know how the mind creates these representations, we need to know the limits and sensitivity of perception

(i. e. Limits: How dark is too dark? How fast is too fast?)
(i. e. Sensitivity: How much change is necessary for a person to notice?)

Question 12

Defining Limits and Sensitivity:
Detectability

Answer 12

The absolute limits of the sensory systems to provide information that a stiumulus is present

Question 13

Definning Limits and Sensitivity:
Discriminability

Answer 13

The ability to determine that two stimuli differ from each other

Question 14

Defining Limits and Sensitivity:
Psychophysical Scaling

Answer 14

Discoverinng the relation between perceived magnitude and physical magnitude

Question 15

Goal of Classical Methods for Detection and Discrimination

Answer 15

To measure thresholds (absolute and difference thresholds) accurately

Question 16

Absolute Threshold

Answer 16

Smallest amount of intensity needed for a person to notice a stimulus

Question 17

Difference Threshold

Answer 17

Smallest amount of diffrence needed for a person to percieve two stimuli as different

Question 18

Method of Limits

Answer 18

• Developed by Fechner
• Absolute threshold: present stimulus intensities in a succession of small increments to an observer (i.e. detecting light)
• Difference threshold: present two stimuli at a time. One remains constant and the other changes in small increments

Question 19

Method of Constant Stimuli

Answer 19

• Developed by Fechner
• Present different stiumli intensities ina random order instead of sequential like the Method of Limits
• Absolute threshold: just use one stimulie that changes intensity at random increments
• Difference threshold: use a constant and a stimuli that changes intensity at random increments

Question 20

Classical Methods: Pros and Cons

Answer 20

• Pros: it’s good to know what is wihin the range of perception; using this research, we know information like the range of visible light
• Cons: these threshold measures are subjective
• we have to believe the observer when s/he says s/he detected the stimulus or difference
• when an observer says ‘yes’ or ‘no’ more often than s/he should, we call this response bias

Question 21

Signal Detection

Answer 21

• Observer is required to discriminate trials on which the stimulus is present from rials on which it is not.
• This addresses response bias b comparing ‘hits’ and ‘false alarms’ when there are different probabilities of the signal being present.
• You can influence the relative rates of signal detection outcomes (i.e. false alarms and misses)
• Emphasize caution (fewer false alarms, but more misses)
• Emphasize getting all the hits (fewer misses, but more false alarms)
• This influence can be from instructions or from the characteristics of the task itself

Question 22

Psychophysical Scaling

Answer 22

• Goal is to develop scales of psychological quantities that can be mapped to physical scales
• i.e. measure sounds and how loud people rate them

Question 23

Scaling Procedures

Answer 23

• Direct: ask the perceiver to rate the perceived intensity of the stimuli
• Indirect: derive the quantitative scale indirectly from a perceiver’s performance at discriminating stimuli (i.e. insead of asking the listener to judge loudness/volume, we’d ask them to descriminate different intensities)

Question 24

Stevens’ Law

Answer 24

• The relationship between physical intensity and psychological magnitude (perceived magnitude)
• S=aIⁿ
• S is (reported) sensory experience
• a is a constant
• I is physical intensity
• n is an exponent that varies from different senses

Question 25

Reaction Time

Answer 25

Defined as the amount of time between the occurence of an event and a person’s *response *

Question 26

Simple Reaction Time (SRT)

Answer 26

• a single response is made after the action occurs
• i.e. when you hear this sound, press this button
• typically range between 150-200 milliseconds (0.15 to 0.2 seconds)
• SRTs in response to auditory stimuli are usually a little faster than SRTs in response to visual stimuli

Question 27

Choice Reaction Time

Answer 27

• more than one response can be made and the correct response depends on the stimulus that occurs
• i.e. press the left arrow key when you see an arrow pointing left, and press the right arrow key when you see an arrow pointing right