Thinking About Psychology: The Science of Mind and Behavior

1. Thinking About Psychology: The Science of Mind and Behavior Charles T. Blair-Broeker Randal M. Ernst

2. Sensation and Perception Chapter 04

3. Sensation Module 09

4. Introduction Module 9: Sensation

5. Sensation/Perception • Pulfrich Effect Demonstration • Describe what occurred • Why did you see the optical illusion? • What aspect of the demonstration represented sensation? Perception?

6. Sensation • The process by which our sensory systems (eyes, ears, and other sensory organs) and nervous system receive stimuli from the environment • A person’s awareness of the world

7. Bottom-Up Processing • Information processing that focuses on the raw material entering through the eyes, ears, and other organs of sensation

8. Perception • The process of organizing and interpreting sensory information

9. Top-Down Processing • Information processing that focuses on expectations and experiences in interpreting incoming sensory information

10. Sensation & Perception How do we construct our representations of the external world? To represent the world, we must detect physical energy (a stimulus) from the environment and convert it into neural signals. This is a process called sensation. When we select, organize, and interpret our sensations, the process is called perception.

11. Bottom-up Processing Analysis of the stimulus begins with the sense receptors and works up to the level of the brain and mind. ASSOCIATE WITH SENSATION. Letter “A” is really a black blotch broken down into features by the brain that we perceive as an “A.”

12. Count the f’s in the following text: • FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXEPERIENCE OF YEARS

13. Top-Down Processing Information processing guided by higher-level mental processes as we construct perceptions, drawing on our experience and expectations. ASSOCIATE WITH PERCEPTION (schemas also) THE CHT

14. CAN YOU READ THIS? • Aoccdrnig to rscheearch at an Biritsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are. The olny iprmoatnt tihng is taht the frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by itslef but the wrod as a wlohe.

15. Making Sense of Complexity Our sensory and perceptual processes work together to help us sort out complex images. “The Forest Has Eyes,” Bev Doolittle

16. Sensing the World Senses are nature’s gift that suit an organism’s needs. A frog feeds on flying insects; a male silkworm moth is sensitive to female sex-attractant odor; and we as human beings are sensitive to sound frequencies that represent the range of human voice.

17. Thresholds Module 9: Sensation

18. Threshold • An edge or a boundary

19. Difference Threshold • The minimum difference that a person can detect between two stimuli 50% of the time • Also called just noticeable difference

20. Absolute Threshold

21. Thresholds: Signal Detection Theory Module 9: Sensation

22. Signal Detection Theory • Set of formulas and principles that predict when we will detect the presence of a faint stimulus (signal) amid background stimulation (noise) • Developed out of the Cold War

23. Signal Detection Theory • Three kinds of variables • Stimulus variables • Environmental variables • Organismic variables

24. Sensory Adaptation Module 9: Sensation

25. Sensory Adaptation • Diminished sensitivity as a result of constant stimulation • If a stimulus is constant and unchanging, eventually a person may fail to respond to it • Examples of Sensory Adaptation in your own world?

26. Sensory Adaptation Diminished sensitivity as a consequence of constant stimulation(unchanging stimulus). Put a band aid on your arm and after awhile you don’t sense it.

27. SENSORY ADAPTATION • Sensory receptors are alert to novelty. Example? • Benefit of sensory adaptation: Focus on informative change in our environment, without distractions of uninformative constant stimulation • Fundamental lesson: We perceive the world not exactly as it is, but as it is useful for us to perceive it.

28. Examples of Sensory Adaptation in your own life

29. Selective Attention Module 9: Sensation

30. Selective Attention • Focusing conscious awareness on a particular stimulus to the exclusion of others • The ability to focus on one stimulus at a time • Allows a person to function in a world filled with many stimuli

31. Dichotic Listening Activity

32. The Visual System: The Nature of Light Module 9: Sensation

33. Pupil Dilation Activity

34. Electromagnetic Energy • An energy spectrum that includes X-rays, radar, and radio waves • A small portion of the spectrum includes light visible to the human eye

35. The Electromagnetic Spectrum

36. Hue • The color of light as determined by the wavelength of the light energy • Includes: red, orange, yellow, green, blue, indigo and violet (ROY G BIV) • The eye can detect 7 million separate hues

37. Wavelength

38. Amplitude • The brightness of light as determined by height of the wave • The taller the wave, the brighter the color

39. Amplitude

40. The Visual System: The Structure of the Visual System Module 9: Sensation

41. Cornea • The clear bulge on the front of the eyeball • Begins to focus the light by bending it toward a central focal point • Protects the eye

42. Parts of the Eye – Cornea

43. Iris • A ring of muscle tissue that forms the colored portion of the eye; creates a hole in the center of the iris (pupil) • Regulates the size of the pupil by changing its size--allowing more or less light to enter the eye

44. Parts of the Eye - Iris

45. Pupil • The adjustable opening in the center of the eye that controls the amount of light entering the eye (surrounded by the iris) • In bright conditions the iris expands, making the pupil smaller. • In dark conditions the iris contracts, making the pupil larger.

46. Parts of the Eye - Pupil

47. Lens • A transparent structure behind the pupil; focuses the image on the back of the eye (retina) • Muscles that change the thickness of the lens change how the light is bent thereby focusing the image • Glasses or contacts correct problems in the lens’ ability to focus.

48. Parts of the Eye - Lens