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 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

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

7. Perception The process of organizing and interpreting sensory information

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

9. Thresholds Module 9: Sensation

10. Threshold An edge or a boundary

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

12. Absolute Threshold

13. Thresholds: Signal Detection Theory Module 9: Sensation

14. 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

15. Signal Detection Theory Three kinds of variables –Stimulus variables –Environmental variables –Organismic variables

16. Sensory Adaptation Module 9: Sensation

17. 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

18. Selective Attention Module 9: Sensation

19. 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

20. Selective Attention Insert “Neisser’s Selective Attention Test” Video #23 from Worth’s Digital Media Archive for Psychology. Instructions for importing the video file can be found in the ‘Readme’ file on the CD-ROM.

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

22. 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

23. The Electromagnetic Spectrum

24. 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

25. Wavelength

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

27. Amplitude

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

29. 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

30. Parts of the Eye – Cornea

31. 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

32. Parts of the Eye - Iris

33. 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.

34. Parts of the Eye - Pupil

35. 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.

36. Parts of the Eye - Lens

37. Inverted Images Play “Perception: Inverted Vision” (5:04) Module #10 from The Brain: Teaching Modules (2 nd edition).

41. Retina Light-sensitive surface with cells that convert light energy to nerve impulses At the back of the eyeball Made up of three layers of cells –Receptor cells –Bipolar cells –Ganglion cells

42. Parts of the Eye - Retina

43. Receptor Cells These cells are present in every sensory system to change (transduce) some other form of energy into neural impulses. In sight they change light into neural impulses the brain can understand. Visual system has two types of receptor cells – rods and cones

44. Rods Visual receptor cells located in the retina Can only detect black and white Respond to less light than do cones

45. Cones Visual receptor cells located in the retina Can detect sharp images and color Need more light than the rods Many cones are clustered in the fovea.

47. Fovea The central focal point of the retina The spot where vision is best (most detailed)

48. Parts of the Eye - Fovea

49. Bipolar Cells Gather information from the rods and cones and pass it on to the ganglion cells Cells that form the middle layer in the retina

50. Ganglion Cells Pass the information from the bipolar cells through their axons Together these cells form the optic nerve. The top layer of the cells in the retina

51. Visual Processing in the Retina

55. Optic Nerve The nerve that carries visual information from the eye to the occipital lobes of the brain

56. Vision and the Brain Play “Visual Information Processing: Elementary Concepts” (9:11) Module #8 from The Brain: Teaching Modules (2 nd edition).

57. Parts of the Eye – Optic Nerve

58. Blind Spot The point at which the optic nerve travels through the retina to exit the eye There are no rods and cones at this point, so there is a small blind spot in vision.

59. Parts of the Eye – Blind Spot

60. Visual Impairment Play “Smart Glasses” (8:13) Segment #9 from Scientific American Frontiers: Video Collection for Introductory Psychology (2 nd edition).

61. The Visual System: Color Vision Module 9: Sensation

62. Trichromatic (three-color) Theory Theory of color vision that says cones are “tuned” to be sensitive to red, green and blue light All the colors we see are a combination of these three colors. Based on work of Helmholtz and Young Similar to the design of a color TV

65. Subtractive Color Mixing When mixing colored paints, each new color SUBTRACTS (soaks up) another wavelength. Red, blue, and yellow combine to make black paint.

66. Additive Color Mixing When mixing colored lights, each new color ADDS another wavelength. Red, green, and blue combine to make white light.

67. Color Deficient Vision People who lack one of the three types of cones Usually the red or green receptors are missing Usually referred to as color blindness In inherited and found more in males

68. Opponent-Process Theory of Color Theory that says color is processed in opponent pairs of color: –Red-green, yellow-blue, black-white Light that stimulated one half of the pair inhibits the other half Ewald Hering Explains the afterimage effect

69. Afterimage Effect

71. Hearing: The Nature of Sound Module 9: Sensation

72. Sound Sound, like light, comes in waves Sound is vibration Features of sound include: –Pitch –Hertz –decibels

73. Pitch A sound’s highness or lowness Dependent on the frequency of the sound wave Is measured as hertz (Hz)

74. Hertz (Hz) A measure of the number of sound wave peaks per second; measures “frequency” Determines the pitch of the sound Human hearing goes from 20 Hz to 20,000 Hz

75. Decibel (dB) A measure of the height of the sound wave Determines the loudness of the sound Sometimes called amplitude

77. Hearing: The Structure of the Auditory System Module 9: Sensation

78. Parts of the Ear – Sound Waves

79. Auditory Canal The opening through which sound waves travel as they move into the ear for processing Ends at the tympanic membrane (eardrum)

80. Parts of the Ear – Auditory Canal

81. Tympanic Membrane (eardrum) The tissue barrier that transfers sound vibration from the air to the tine bones of the middle ear Can be damaged by objects in the ear or exceptionally loud noises

82. Parts of the Ear – Tympanic Membrane

83. Ossicles Three tiny bones that transfer sound waves from the eardrum to the cochlea Hammer, anvil and stirrup

84. Parts of the Ear - Occicles

85. Cochlea A hearing organ where sound waves are changed into neural impulses The major organ of hearing Filled with fluid; a snail shaped body tube

86. Parts of the Ear - Cochlea

87. Oval Window The point on the surface of the cochlea which receives the sound vibration from the ossicles As the oval window vibrates, the fluid in the cochlea vibrates.

88. Parts of the Ear – Oval Window

89. Hair Cells The receptor cells for hearing in the cochlea that change sound vibrations into neural impulses Similar to the rods and cones within the eye

90. Parts of the Ear - Hair Cells

91. Auditory Nerve The nerve that carries sound information from the ears to the temporal lobes of the brain

92. Parts of the Ear – Auditory Nerve

93. Semicircular Canals Organs in the inner ear used in sensing body orientation and balance (vestibular sense) Relies on fluid in the canals Spinning in circles disrupts the fluid.

94. Parts of the Ear – Semicircular Canals

95. Divisions of the Ear Ear’s structure can be divided into: –The outer ear –The middle ear –The inner ear

96. Divisions of the Ear

99. Hearing: Sound Localization Module 9: Sensation

100. Localization of Sound Locating where sound is originating from Done through two cues: –Which ear hears the sound first? –Which ear hears the louder sound?

101. Localization of Sound

102. Other Senses: Taste Module 9: Sensation

103. Taste Taste is a chemical sense. Receptor cells are located primarily on the tongue and in the mouth. Four different tastes: –Salty, sweet, sour and bitter Damaged taste receptor cells are replaced within a few days.

104. Supertasters People with an abundance of taste receptors Approximately 25% of the population

105. Nontasters People with a minimum of taste receptors Taste with less intensity than the rest of the population Approximately 25% of the population

106. Supertasters and Nontasters Play “Tasters and Supertasters” (14:00) Segment #12 from Scientific American Frontiers: Video Collection for Introductory Psychology (2 nd edition).

107. Other Senses: Smell Module 9: Sensation

108. Smell Smell is a chemical sense. Olfactory cells in the upper nasal passages detect molecules in the air. Taste and smell interact to produce flavor.

109. Olfactory Cells The chemical receptor cells for smell Located in the nasal passages

110. Smell

113. Other Senses: Touch Module 9: Sensation

114. Touch Touch receptors are on the skin Four basic skin senses are –Pain, warmth, cold, and pressure All skin sensations are a combination of these four basic senses

115. Gate-control Theory of Pain Pain messages travel on one set of nerve fibers containing pain gates. The gates are open when pain is felt. Other sensory messages go through another set of fibers. The nonpain fibers can close the pain gates to stop the sense of pain.

116. Pain and Phantom Pain Play “Phantom Limb Pain: Fooling the Mind” (4:29) Segment #20 from The Mind: Psychology Teaching Modules (2 nd edition).

117. Other Senses: Body Senses Module 9: Sensation

118. Kinesthetic Sense The system for sensing the position and movement of individual body parts Relies on receptor cells from the muscles and joints One’s leg “falling asleep” is a disruption of the kinesthetic sense

119. Vestibular Sense The system for sensing body orientation and balance Relies on fluid in the semicircular canals of the inner ear Spinning in circles disrupts the fluid.

120. Parts of the Ear – Semicircular Canals

121. Kinesthetic and Vestibular Sense Play “Sensory-Motor Integration” (3:27) Module #11 from The Brain: Teaching Modules (2 nd edition).

122. The End

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