1. Unit 4: Sensation, Perception and States of Consciousness
JHS AP Psychology
Unit 4: Sensation, Perception and States of Consciousness
Essential Task 4-5: Essential Task 4-5: Describe general principles of perception/ top down processing (organizing and integrating sensation) that promote stable awareness of the external world with specific attention to the Gestalt principles of figure/ground, closure, proximity, connectedness, similarity and the mono and binocular cues for depth perception).
Logo Green is R=8 G=138 B= Blue is R= 0 G=110 B=184
Border Grey is R=74 G=69 B=64

2. Perceptual Constancies
Sensation
Vision
The Eye
Theories
Hearing
The Ear
Other Senses
Smell
Taste
Pain
Gestalt Principles
Perceptual Constancies
Perception
Basic Principles
Visual Illusions
Depth Perception
We are here

3. States of Consciousness
Altered States of Consciousness
Waking Consciousness
Daydreaming and Fantasy
Sleep
Circadian Rhythm
Stages/REM
Dreams
Disorders
Drug-Altered Consciousness
Depressants
Hallucinogens
Stimulants
Hypnosis
Hidden Observer
Actor
Meditation
Substance Abuse

4. Essential Task 4-5:
Outline
Describe general principles of perception/top down processing
Gestalt principles of:
Figure-ground
closure
proximity
connectedness,
similarity
Depth perception
Monocular cues
Binocular cues

5. Our brains are meaning machines
We organize the sensory information coming into our brains.
We make assumptions about the sensory information. Oftentimes our perception is greater than the sum of the parts actually presented to our senses.

6. Sidewalk chalk art
3D art

7. Gestalt Psychology From the German word meaning ‘the whole’
Studied human perceptual self-organizing tendencies.
Found that the brain creates a coherent perceptual experience that is more than simply the sum of the available sensory information
AND it does this in predictable ways
So predictable that artists can exploit our common perceptions to do things like 3D Art
OBJECTIVE 3| Describe Gestalt psychology's contribution to our understanding of perception.

8. First step in visual PERCEPTION
Determine Figure from the background (figure-ground)
We organize the visual field into objects (figures) that stand out from their surroundings (ground).

9. Examples of figure-ground
OBJECTIVE 4| Explain the figure-ground relationship and identify principles of perceptual grouping in form perception.
What you make the figure and what you back the background determines your perception

10. Examples of figure-ground

11. Figure-ground

12. Figure-ground examples

13. We organize by closure

14. Closure

15. We organize by Proximity

16. Proximity

17. Proximity and Closure

18. We organize by Similarity

19. Similarity

20. We organize by similarity

21. Continuity

22. Connectedness
The Principle of Common Region states that objects that are within the same region are perceptually grouped together. 

23. They are predictable and therefore they can be exploited.

25. How do we perceive forms?
Perceptual Constancy
Our tendency to perceive objects as stable and unchanging despite changing sensory information
Size constancy
Shape constancy
Color constancy

27. Depth Perception
Depth perception enables us to judge distances. Gibson and Walk (1960) suggested that human infants (crawling age) have depth perception. Even newborn animals show depth perception.
OBJECTIVE 5| Explain the importance of depth perception, and discuss the contribution of visual cliff research to our understanding of this ability.
Visual Cliff

28. Binocular Cues
Depth perception that you have because you have two eyes!
Retinal Disparity
Convergence

29. Binocular Cues: Retinal Disparity
Retinal disparity: Images from the two eyes differ.
While focusing far away try touching your fingers about 5 inches directly in front of your eyes. You will see a “finger sausage”
The amount of disparity (difference) between the two images can be used as a cue for distance
Try holding up two fingers one in front of the other. Focus on the front one (you should now see two images of the back one). Now move the back one away from, then back towards you, while still focusing on the front one.

30. Binocular Cues: Convergence
Convergence: Neuromuscular cues. When two eyes move inward (towards the nose) to see near objects and outward (away from the nose) to see faraway objects.
OBJECTIVE 6| Describe two binocular cues for perceiving depth, and explain how they help the brain to compute distance.

31. Monocular Cues
Relative Size: If two objects are similar in size, we perceive the one that casts a smaller retinal image to be farther away.
OBJECTIVE 7| Explain how monocular cues differ from binocular cues, and describe several monocular cues for perceiving depth.

32. Monocular Cues
Interposition: Objects that occlude (block) other objects tend to be perceived as closer.

33. Monocular Cues
Relative Clarity: Because light from distant objects passes through more light than closer objects, we perceive hazy objects to be farther away than those objects that appear sharp and clear.

34. Monocular Cues
Texture Gradient: Closer objects tend to have a courser texture than to far way objects

35. Monocular Cues
Relative motion: Objects closer to a fixation point move faster and in opposing direction to those objects that are farther away from a fixation point, moving slower and in the same direction.

36. Monocular Cues
Linear Perspective: Parallel lines, such as railroad tracks, appear to converge in the distance. The more the lines converge, the greater their perceived distance.

37. Monocular Cues
Light and Shadow: Nearby objects reflect more light into our eyes than more distant objects. Given two identical objects, the ones that are shaded on top are seen as “sticking out toward us”

38. Perception of Movement
Apparent movement
Illusion that still objects are moving
Autokinetic illusion
Perceived motion of a single object due to eye movements on an ‘impoverished background’
Stroboscopic motion (Click here)
Created by a rapid series of still pictures
Phi phenomenon
Apparent motion created by lights flashing in sequence