1. Perception

2. Agenda
1. Bell Ringer: Reading Quiz 2. Lecture: Perception and Illusion (20) 3. Inattentional Blindness Activity (10) - Giving Directions Clip (5) 4. Perceptual Illusions (10) 5. Handout 6-4 (15)

3. Perception is the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

4. Types of Perceptions
Form Perception – we must perceive a figure from its ground
Depth Perception – transform 2D into 3D
Motion Perception – brain computes motion as images move across retina
Perceptual Interpretation – how we recognize an object

5. Perception Selective Attention :
the focusing of conscious awareness on a particular stimulus.

6. Cocktail party effect:
Is the ability to attend selectively to one voice among many.

7. http://www. youtube. com/watch

8. Inattentional Blindness
Inability to see an object or a person in our midst.
Simmons and Chabris (1999) showed that 1/2 of the observers failed to see the gorilla suited assistant in a ball passing game

9. Change Blindness A form of inattentional blindness.
When you do not notice when something changes because you are so focused on something else.

10. Two-thirds of individuals giving directions failed to notice a change in the individual asking directions.

11. Change Blindness
Stop at 2:20

12. Perceptual Illusions
Muller-Lyer (1889)
Which line is longer?

13. Perceptual Illusions

14. Tall Arch The vertical dimension of the arch looks longer than the horizontal dimension. However, both are the same

15. Perceptual Illusions

16. http://www. youtube. com/watch

17. The Ames room is designed to demonstrate the size-distance illusion.

18. Perceptual Illusions Helen Ross 1975

19. Perceptual Illusions
The figure on the right gives the illusion of a blue hazy “worm” when it is nothing more else but blue lines indenticial to the figure on the left.

20. Perceptual Illusions

21. Perceptual Organization
Visual Capture – the tendency for vision to dominate the other senses.
Gestalt – an organized whole. The tendency to integrate pieces of information into meaningful wholes.
Think puzzles

22. Gestalt psychologists are fond of the saying that in perception the whole may exceed the sum of its parts. Bottom-up and top-down processing

23. Perceptual Organization Necker Cube

24. Form Perception
Figure-Ground – the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).

25. Example of figure - ground
At a party, the person you are talking to is the FIGURE and all the other people at the party are part of the GROUND.

26. Figure – Ground

27. Figure-Ground

28. Figure Ground

29. Form Perception
Grouping – the perceptual tendency to organize stimuli into coherent groups.

30. Grouping Principles Proximity – group nearby figures together
Similarities – group figures that are similar
Continuity – perceive continuous patterns
Connectedness – spots, lines, and areas are seen as a unit when connected
Closure – fill in the gaps

31. Grouping Principles

32. Closure

33. Grouping Principles – they can lead up astray.