1. Dr.safeyya Adeeb Alchalabi
Perception
Dr.safeyya Adeeb Alchalabi

12. Perception
Is the method by which the brain takes all the sensations a person experiences at any given moment and allows them to be interpreted
in some meaningful fashion.

13. constancies Perceptual constancy:
Something that remains the same, the property of remaining stable and unchanging.

14. Perceptual constancy Size constancy
The tendency to interpret an object as always being the same size, regardless of its distance from the viewer (or the size of the image it casts on the retina).

15. Perceptual constancy Shape constancy
Is the tendency to interpret the shape of an object as constant, even when changes on the retina.

16. Perceptual constancy Brightness constancy
The tendency to perceive the apparent brightness of an object as the same even when the light conditions change.

17. Gestalt principles
The tendency to group objects and perceive whole shapes.

18. Gestalt psychology
Back to Germany, by the psychologist Max Wertheirmer.
Wertheirmer believed that psychological event such as perceiving and sensing could not broken down in to any smaller elements and still be properly understood, so perception can only be understood as whole, entire event.
“The whole is greater than the sum of its parts”
Wertheirmer and others believed that people naturally seek out patterns (“whole”) in the sensory information available to them.

19. Gestalt psychology
Wertheimer and others devoted their efforts to studying sensation and perception in their new perspective, Gestalt psychology.
(Gesh-TALT) is a German word meaning “an organized whole” or “configuration”, which fit well with the focus on studying whole patterns rather than small pieces of them.

20. Gestalt psychology
Today, Gestalt ideas are part of the study of cognitive psychology, a field focusing not only on perception but also on learning, memory, thought processes, and problem solving.
The Gestalt approach has also been influential in psychological therapy, becoming the basis for a therapeutic technique called Gestalt therapy.

21. Gestalt principles

22. Gestalt principles Figure-ground relationships
Refer to the tendency to perceive objects or figures as existing on a background.
Organization depends what we see as figure (object) and what we perceive a ground (context).

24. Figure-ground relationships

25. In which the figure and the ground seem to switch back and forth.
Reversible figures
In which the figure and the ground seem to switch back and forth.

26. Figure-ground relationships
People seem to have a preference for picking out figures from background even as early as birth.

27. Gestalt principles of grouping
Proximity (nearness)
Another very simple rule of perception is the tendency to perceive objects that are close to one another (in space or time) as part of the same grouping (or belong together).

28. Gestalt principles of grouping
Similarity
Refers to the tendency to perceive things that look similar as being part of the same group.
(Objects that have similar characteristics are perceived as a unit).

29. Gestalt principles of grouping
Closure
is the tendency to complete figures that are incomplete.
(we perceive figures with gaps in them to be complete).

30. Gestalt principles of grouping
Continuity
It refers to the tendency to perceive things as simply as possible with continuous pattern rather than with a complex, broken-up pattern.
(we tend to perceive figures or objects as belonging together if they appear to form a continuous pattern).

31. Gestalt principles of grouping
Common region
The tendency is to perceive objects that are in a common area or region as being in a group.

32. Depth perception The capability to see the world in three dimensions.
It seems to develop very early in infancy, if it is not actually present at birth.

33. Depth perception

34. Perceptual illusion A false perception of actual stimuli involving
a misperception of size, shape, or the relationship
of on element to another.

35. Perceptual illusion

36. Feature detectors They respond to specific features of a stimulus.
Simple cells
Neurons in the primary visual cortex that respond best to bars of light of a specific orientation.
Complex cells which respond to orientation and movement.
End-stopped cells which respond best to corners, curvature, or sudden edges.

38. Muller-Lyer illusion

39. Moon illusion

42. Perceptual set (perceptual expectancy)

59. Thank you