Unit 4: Sensation and Perception

1. Unit 4:Sensation and Perception

2. Sensing the World: Some Basic Principles

3. Introduction • Sensation • Perception • Are one continuous process

4. Introduction • Bottom-up processing • Top-down processing

5. Selective Attention • Selective Attention • Cocktail party effect

6. Selective AttentionSelective Attention and Accidents • Cell phone use and car accidents

7. Selective AttentionSelective Inattention • Inattentional blindness

8. Selective AttentionSelective Inattention • Change blindness • Change deafness • Choice blindness • Choice-choice blindness • Pop-out

9. Thresholds • Psychophysics

10. ThresholdsAbsolute Thresholds • Absolute threshold • 50 % of the time

11. ThresholdsSignal Detection • Signal-detection theory • Ratio of “hits” to “false alarms”

12. ThresholdsSubliminal Stimulation • Subliminal (below threshold) • Priming • Masking stimulus • Subliminal persuasion

13. ThresholdsDifference Thresholds • Difference threshold • Just noticeable difference (jnd) • Weber’s Law

14. Vision

15. The Stimulus Input: Light Energy • Transduction (transform) • Wavelength • Hue (color) • Wavelength • Intensity • Wave amplitude

16. The Eye • Cornea • Pupil • Iris • Lens • accommodation • Retina

17. The Structure of the Eye

18. The Structure of the Eye Cornea = outer covering of the eye.

19. The Structure of the Eye Pupil = the adjustable opening in the center of the eye through which light enters.

20. The Structure of the Eye • Iris = a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. • The iris dilates/constricts in response to changing light intensity

21. The Structure of the Eye Lens = the transparent structure behind the pupil that changes shape to help focus images on the retina.

22. The Structure of the Eye Retina = the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

23. The EyeThe Retina • Rods and Cones Rods Cones

24. Rods versus Cones

25. The Retina’s Reaction to Light

26. The Retina’s Reaction to Light

27. The Retina’s Reaction to Light

28. The Retina’s Reaction to Light

29. The Retina’s Reaction to Light

30. The EyeThe Retina • Optic nerve • Blind spot • Fovea

31. The Structure of the Eye Blind Spot = the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.

32. The Structure of the Eye Fovea = the central focal point in the retina, around which the eye’s cones cluster.

33. The Structure of the Eye Optic Nerve = the nerve that carries neural impulses from the eye to the brain.

34. Visual Information ProcessingVisual Cortex

35. Pathways from the eyes to the visual cortex

36. Pathways from the eyes to the visual cortex

37. Pathways from the eyes to the visual cortex

38. Pathways from the eyes to the visual cortex

39. Color Vision • Young-Helmholtz trichromatic (three color) theory • Red – Green - Blue • Monochromatic vision • Dichromatic vision

40. Color Vision • Opponent-process theory • Three sets of colors • Red-green • Blue-yellow • Black-white • Afterimage

41. Hearing

42. The Stimulus Input: Sound Waves • Audition • Amplitude • loudness • Frequency • Pitch

43. The Ear • Outer ear • Auditory canal • Ear drum

44. The structure of the ear The ear is divided into the outer, middle and inner ear.

45. The structure of the ear The sound waves travel down the auditory canal to the eardrum.

46. The structure of the ear Eardrum = tight membrane that vibrates when struck by sound waves.

47. The structure of the ear Eardrum

48. The Ear • Middle ear • Hammer, anvil, stirrup

49. The structure of the ear Bones of the middle ear = the hammer, anvil, stirrup which vibrate with the eardrum.

50. The structure of the ear Hammer