Parallel processing / Divided attention

1. 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.

2. 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

3. Gestalt grouping principles • Proximity:

4. Gestalt grouping principles • Similarity:

5. Gestalt grouping principles • Common fate:

6. Gestalt grouping principles • Good Continuation:

7. Gestalt grouping principles • Closure:

8. 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

9. Emergent Features • A global property of a set of stimuli that is not apparent by examining the stimuli in isolation

10. Emergent Feature

11. Dan’s movie

12. Overlapping views & HUDs • Logic: it’s easier to extract information from two items when they are close together than when they are farther apart.

13. 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).

14. 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.

15. Conformal Symbology

16. Conformal Symbology

17. 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???

18. 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

19. Focused attention Response Competition Redundancy Gain

20. Object based attention • When you attend to part of an object, you attend to all of the object. Demo: “Name this word”

21. Red

22. 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).

23. 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

24. 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

26. 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

27. 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.

28. 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

29. 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 = cautionblue = cold green = go

30. 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

31. 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

32. 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?

33. Color coding Limitations of color coding: • Stereotypes red-yellow-green stoplight pattern might not have the same meaning in different parts of the world

34. 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.