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					 Parallel processing / Divided attention
• What is parallel processing?
  – items are processed all at once.
  – Example: letters in a word are processed all at
    once, not one-at-a-time.
 Early vision / perceptual organization
• Early in the visual system, information is
  extracted and organized in parallel.

  – much of this is effortless, automatic, and does not
    require attention.

  – extracts features and organizes them into objects.
     • e.g. Biederman, Geons, and Recognition by
       compenents
        Gestalt grouping principles
• Proximity:
        Gestalt grouping principles
• Similarity:
      Gestalt grouping principles
• Common
  fate:
       Gestalt grouping principles
• Good Continuation:
       Gestalt grouping principles
• Closure:
            Global Precedence
• Items are examined at several different scales
• Large is examined before small
                EEEEEEEE
                E          E
                E          E
                E      E
                EEEEEEE
                E     E
                E      E
                E    E
                E          E
             Emergent Features
• A global property of a set of stimuli that is not
  apparent by examining the stimuli in isolation
Emergent Feature
Dan’s movie
        Overlapping views & HUDs
• Logic: it’s easier to extract information from two
  items when they are close together than when
  they are farther apart.
                   Problems
•   Allows, but does not guarantee parallel
    processing.

•   The two displays might be treated as 2
    different sources of information

•   Pay too much attention to the HUD (cognitive
    tunneling).
              Costs & Benefits
• Bad: Can clutter the display, making items less
  easy to detect or process.

• Good: Works particularly well when the
  observer expects the stimulus
  – conformal symbology is an extreme example of
    this.
Conformal Symbology
Conformal Symbology
             Focused Attention
• Tight spacing makes it easier for us to share
  our attention between two items.

• However, if items are too close, it becomes
  difficult to focus on a single item.

• How tightly can we focus our attention???
                  Focused Attention

•   Flanker Task:
    –   respond to middle item (L or R), ignore the other items
        (“flankers”).
    –   3 spaces, 3 flanker/target compatibilities.

         compatible         incompatible            neutral
–           LLL                 LRL                  XRX

–         R R R                R L R                X L X

–         L   L   L           L   R   L         X     R       X
              Focused attention

Response
Competition




Redundanc
y Gain
          Object based attention
• When you attend to part of an object, you
  attend to all of the object.



Demo: “Name this word”
Red
                 Stroop Effect
• The reason that the Stroop task is so difficult
  (at least when the names and colors
  mismatch), is because you automatically
  process all parts of the object (color, form).
      Proximity-Compatibility Principle
• Items that have close processing proximity should have
  close display proximity.

   – Display proximity - how close are two components?
      • distance
      • other properties, e.g. same color
      • Gestalt grouping or part of the same object
  Proximity-Compatibility Principle
– processing proximity -
   • the extent to which 2 sources of information are
     used in the same task.
   • example: altimeter & rate of climb gauge
     Proximity-Compatibility Principle
•   Moving items close together increases the
    likelihood that they will be processed together,
    as does making them part of the same object
     Proximity-Compatibility Principle
•   Moving items close together increases the likelihood that they will
    be processed together, as does making them part of the same
    object
•   Close proximity can cause emergent features
    to occur. If the emergent feature is not part of
    the task or is unintended, this can hurt
    performance.
     Proximity-Compatibility Principle
•   Moving items close together increases the likelihood that they will
    be processed together, as does making them part of the same
    object
•   Close proximity can cause emergent features to occur. If the
    emergent feature is not part of the task or is unintended, this can
    hurt performance.
•   Close proximity can create clutter or response
    conflict. If the task is likely to call for focused
    attention on only a single item at a time, then
    avoid close proximity
                     Color coding
For the 97% of the population who are not color blind,
    color coding can be of great benefit:

   – highlighting - if the color is significantly different from
     the rest of the display.
   – stereotypical meanings:
     red = stop                     red = hot
     yellow = caution               blue = cold
     green = go
                       Color coding
For the 97% of the population who are not color blind,
    color coding can be of great benefit:

   –   highlighting - if the color is significantly different from the
       rest of the display.
   –   stereotypical meanings
   – used to tie together spatially separate objects
     – mixing board
   – Redundant coding
     – a traffic light uses color and location
                    Color coding
Limitations of color coding:
• Sensory
   •   limit the number of colors to 5 or 6
       Most people can only easily discriminate between 5
           and 6 colors.

   •   color is not perceptible under low-light conditions
                         Color coding
Limitations of color coding:
•     Sensory
    •    limit the number of colors to 5 or 6
    •    color is not perceptible under low-light conditions
•   Cognitive
    •   Color does not imply an ordered continuum
    •   Is red ‘more’ than green?
                    Color coding
Limitations of color coding:
• Stereotypes
   red-yellow-green stoplight pattern might not have the
       same meaning in different parts of the world
                       Color coding
Limitations of color coding:
•    Stereotypes
    red-yellow-green stoplight pattern might not have the same meaning
        in different parts of the world
•   Coding
    color coding should be relevant and consistent.

				
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posted:6/13/2013
language:English
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