CHAPTER
3Sensation and Perception
Quote of the week: One’s perception is one’s reality.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Enduring Issues
To what extent do our perceptual experiences accurately reflect what is in the outside world? Diversity-
UniversalityDiversity-
Universality
Stability-ChangeStability-Change
Mind-BodyMind-Body
Nature-NurtureNature-Nurture
Person-SituationPerson-Situation
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Enduring Issues
In what ways do our experiences of the outside world change as a result of experience over the course of our lives?
Diversity-UniversalityDiversity-
Universality
Stability-ChangeStability-Change
Mind-BodyMind-Body
Nature-NurtureNature-Nurture
Person-SituationPerson-Situation
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Enduring Issues
To what extent do people around the world perceive events in the same way?
Diversity-UniversalityDiversity-
Universality
Stability-ChangeStability-Change
Mind-BodyMind-Body
Nature-NurtureNature-Nurture
Person-SituationPerson-Situation
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Enduring Issues
In what ways do our experiences depend on biological processes?
Diversity-UniversalityDiversity-
Universality
Stability-ChangeStability-Change
Mind-BodyMind-Body
Nature-NurtureNature-Nurture
Person-SituationPerson-Situation
The Nature of Sensation
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
e n s a t i o ne n s a t i o n
The experience of
sensory stimulation
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
• Difference threshold: Smallest change in stimulation that can be detected 50% of the time
• Absolute threshold: Least amount of energy that can be detected as a stimulation 50% of the time
LEARNING OBJECTIVE: Explain the difference between absolute and differencethresholds and the effect of adaptation on sensory thresholds. Summarize the evidence for subliminal perception and extrasensory perception.
Sensory Thresholds
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Adaptation
Adaptation:An adjustment of the senses to the level of stimulation they are receiving
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Subliminal Perception
Subliminal stimuli: Stimuli below the level of conscious awareness
Vision
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
LEARNING OBJECTIVE: Describe the role of rods, cones, bipolar cells, ganglion cells, the optic nerve, the optic chiasm, and feature detectors in the brain in causing a visual experience.
The Visual System
Images adapted from LivePsych by Pearson, Inc.
Light enters the eye through the cornea.
It passes through the pupil, and is focused by the lens onto the retina.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
The Receptor Cells
• Cones located in fovea– Day vision (color)
• Rods in periphery– Night vision
(light and dark)
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
The Receptor Cells
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Dark adaptation:Increased sensitivity of rods and cones in darkness
Our eyes adjust to different levels of stimulation based on changes in the sensitivity of rods and cones.
Adaptation
Light adaptation:Decreased sensitivity
of rods and cones in bright light
LEARNING OBJECTIVE: Explain how dark and light adaptation affect our vision and how they cause afterimages.LEARNING OBJECTIVE: Explain how dark and light adaptation affect our vision and how they cause afterimages.
Afterimage“The gray-and-white afterimage (in the figure at right) appears because the part of the retina that is exposed to the dark stripes of the upper square becomes more sensitive (dark adapted). The area exposed to the white part of the upper square becomes less sensitive (light adapted). When you shift your eyes to the lower square, the less sensitive parts of the retina produce the sensation of gray rather than white. The afterimage fades within a minute as the retina adapts again, this time to the solid white square.”
– Page 88 (Morris & Maisto)
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
From Eye to Brain
1. Rods and cones are connected to bipolar cells.
2. Bipolar cells hook up with ganglion cells.
3. Axons of ganglion cells join to form optic nerve, which carries messages to the brain.
Images adapted from LivePsych by Pearson, Inc.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Beau: Optical Illusions
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Color Vision
LEARNING OBJECTIVE: Distinguish between hue, saturation, brightness, additive and subtractive color mixing. Explain the two major theories of color perception.
Hues:Aspects of color that correspond to names such as red, green, and blue
Saturation:The vividness or richness of a hue
Brightness:The nearness of a color to white as opposed to black
Increasing saturation
Increasing saturation
Increasing brightnessIncreasing brightness
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Neil Harbisson: Hearing Color
Hearing
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Sound
Frequency – hertz (Hz): waves (cycles) per second
• Pitch– High– Low
LEARNING OBJECTIVE: Explain the characteristics of sound waves and their effect on the sensation we call sound.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Sound
Amplitude: decibelsVolume
– soft to loud
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Images adapted from LivePsych by Pearson, Inc.
LEARNING OBJECTIVE: Describe the path that information about sound travels from the ears to the brain. Explain place theory, frequency theory, and the volley principle.
The Ear
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Deafness• Approx. 28 million Americans: Some
form of hearing loss
• Treatments: Hearing aids, surgery, cochlear implants
Tinnitus • Steady, high-pitched hum
• Affects approx. 1 of 8 persons
• Treatments: Drug therapies, “white noise” implants, biofeedback
Hearing Disorders
LEARNING OBJECTIVE: Explain the two major kinds of hearing disorders (deafness and tinnitus).
The Other Senses
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
LEARNING OBJECTIVE: Describe how stimuli give rise to smells and tastes.
Smell
Source: Human Anatomy and Physiology by Anthony J. Gaudin and Kenneth C. Jones. Copyright © 1989. Reprinted by permission.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Taste
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
LEARNING OBJECTIVE: Distinguish between the kinesthetic and vestibular senses.
Muscle movement
Posture
Strain on muscles, joints
Equilibrium and body position in space
Kinesthetic and Vestibular Senses
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
The skin’s nerve receptors send nerve fibers to the brain by two routes:
LEARNING OBJECTIVE: Explain how sensory messages are sent from the skin to the brain. Summarize the sources of differences among people in the degree of pain they experience.
• medulla, thalamus sensory cortex
• thalamus reticular formation
The Skin Sense
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Pain
social
Bio psychoBiopsychosocial
Theory
Perception
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
The brain’s interpretation
of sensory information so
as to give it meaning
e r c e p t i o ne r c e p t i o n
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Based on the idea that people have a natural tendency to force patterns onto whatever they
see
LEARNING OBJECTIVE: Distinguish between sensation and perception. Explain the Gestalt principles of perceptual organization. Describe the several perceptual constancies.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Figure Ground Proximity Similarity
Closure Continuity
Perceptual Organization: Gestalt PrinciplesPerceptual Organization: Gestalt Principles
Figure Ground Proximity Similarity
Closure Continuity
Perceptual Organization: Gestalt Principles
Figure Ground Proximity Similarity
Closure Continuity
Perceptual Organization: Gestalt Principles
Figure Ground Proximity Similarity
Closure Continuity
Perceptual Organization: Gestalt Principles
Figure Ground Proximity Similarity
Closure Continuity
Perceptual Organization: Gestalt PrinciplesPerceptual Organization: Gestalt Principles
Perceptual Constancies“Perceptual constancy refers to the tendency to perceive objects as relatively stable and unchanging despite changing sensory information. Once we have formed a stable perception of an object, we can recognize it from almost any position, at almost any distance, under almost any illumination. A house looks like a house day or night and from any angle.”
– Page 110 (Morris & Maisto)
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Other Rules of Perception
- Experience plays into perception.
- Memory plays into perception.
- Expectation plays into perception.
- We judge distance and depth.
- How is movement perceived?
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Perception of Movement
Real movement:Physical displacement of an object from one position to another
Apparent movement:Perception of movement in objects that are actually standing still
–Autokinetic illusion–Stroboscopic motion–Phi phenomenon
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Visual Illusions
Perceptual illusions:Stimulus contains misleading cues that give rise to inaccurate or impossible perceptions
LEARNING OBJECTIVE: Explain how visual illusions arise.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Motivation and emotionMotivation and emotion
ValuesValues
ExpectationsExpectations
Cognitive styleCognitive style
Experience and cultureExperience and culture
PersonalityPersonality
LEARNING OBJECTIVE: Describe how observer characteristics and culture can influence perception.
Observer Characteristics
11
22
33
44
55
66
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Other Impacts on Your Perception: Attention
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Other Impacts on Your Perception: Perspective
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Quote of the week: One’s perception is one’s reality.
“Smell and vision are just two of the senses giving us a window on the
world… [all] combine in a rich mosaic of awareness forming the basis of
consciousness. It is sensation that gives us connections both to our own
selves and to our surroundings” (Morris & Maisto, 2013, p. 81).
Optional Activities
When we look at the world around us, how much are we really seeing? Let’s find out.
On the following slide you will be shown two images flashing alternately. The images are identical except for one major change. See if you can spot the change before time runs out. Then try this again with another set of images.
Image #1(Click anywhere to begin)
CONTINUETRY AGAIN
Image #2(Click anywhere to begin)
CONTINUETRY AGAIN
These slides illustrate that human beings are able to pay attention to only part of the visual sensations that they are exposed to on a moment-by-moment basis. These are the parts that are remembered. This demonstration reminds us that the road between sensation and perception has many twists and turns.
The Blind Spot
Draw two small circles (about six inches apart) on your paper. Hold the paper out in front of you. Close your right eye and stare at the right dot with your left eye. Slowly bring the paper closer to your face. As you do this, the left dot will disappear.
After Images
Visual sensations that persist after the initial stimulus has been removed are called “afterimages.”
On the next slide you will see a picture of a flag with a white dot in the middle. Stare at the dot until the screen changes. Do not take your eyes off of the white dot.
Copyright ©Pearson Education 2013
Copyright ©Pearson Education 2013
Trichromatic theory cannot account for afterimages like the one that you just saw (and may still be seeing). In order to explain such perceptual phenomena, a theory is needed that explains photoreceptor activity differently.
Acknowledgments
Slide # Image Description Image Source
text template upside down blue sky & grass ©iStockphoto.com/Konrad Lew
chapter template
hand touching grass ©iStockphoto.com/Catalin Plesa
3 looking ©iStockphoto.com/Leah Marshall
4 child and adult looking at same thing ©iStockphoto.com/hanhanpeggy
5 Indian woman cooking ©iStockphoto.com/Vikram Raghuvanshi Photography
5 U.S. woman cooking ©iStockphoto.com/Frantysek
6 diagram: eye Adapted from LivePsych by Pearson, Inc.
8 icon: wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt
8 car on road ©iStockphoto.com/slobo
9 scale ©iStockphoto.com/Alex Slobodkin
9 feather ©iStockphoto.com/Tihis
10 diagram: sensory threshold Morris/Maisto, 9/e p. 83
11 pierced man ©iStockphoto.com/anna karwowska
12 bucket of popcorn ©iStockphoto.com/PMSI Web Hosting and Design
13 ESP person ©iStockphoto.com/Juanmonino
15 video: pupil Adapted from LivePsych by Pearson, Inc.
15 video: pen Adapted from LivePsych by Pearson, Inc.
15 diagram: eye Adapted from LivePsych by Pearson, Inc.
16 diagram: electromagnetic spectrum Morris/Maisto, 9/e p. 87
17 book ©iStockphoto.com/José Carlos Pires Pereira
17 wood desk ©iStockphoto.com/tanya costey
17 receptor cells animations Tutis Villis
18 table: rods & cones Morris/Maisto, 9/e p. 86
18 book ©iStockphoto.com/José Carlos Pires Pereira
18 wood desk ©iStockphoto.com/tanya costey
19 dark night ©iStockphoto.com/Soubrette
19 bright day ©iStockphoto.com/Online Creative Media
20 Open Your Book - textbook cover Shutterstock
20 Open Your Book - textbook background From Ciccarelli, Psychology, 1/e pp. 213-214
20 Open Your Book - open textbook From Ciccarelli, Psychology, 1/e pp. 114-115
20 illustration: afterimage Morris/Maisto, 9/e p. 88
21 icon: helmet ©istockphoto.com/Li Shen Jun
21 illustration: eye structure Adapted from LivePsych by Pearson, Inc.
22 illustration: brain hemispheres & vision Morris/Maisto, 9/e p. 89
23 illustration: saturation and brightness Morris/Maisto, 9/e p. 90
24 illustration:additive color Morris/Maisto, 9/e p. 91
24 illustration:subtractive color Morris/Maisto, 9/e p. 91
25 red, green, blue color wavelengths animations Derek Borman
25 vase of flowers ©iStockphoto.com/ryasick
26 icon: classic studies car ©istockphoto.com/Brian Sullivan
27 icon: wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt
27 scrap of paper ©istockphoto.com/Trevor Hunt
27 red roses ©iStockphoto.com/borchee
29 piano ©iStockphoto.com/Christian Waadt
29 sound: high note, wavelengths Derek Borman
29 sound: low note, wavelengths Derek Borman
30 woman singing ©iStockphoto.com/afhunta
30 sound: volume, wavelengths Derek Borman
31 chart: decibels Morris/Maisto, 9/e p. 95
31 earphones ©iStockphoto.com/Aldra
32 piano and violin ©iStockphoto.com/Yenwen Lu
33 illustrations: structure of the ear Adapted from LivePsych by Pearson, Inc. and Tutis Villis
34 illustration: hair cell Morris/Maisto, 9/e p. 96
35 sound: high note Derek Borman
35 sound: low note Derek Borman
35 illustration: theories of hearing Adapted from LivePsych by Pearson, Inc. and Tutis Villis
37 person signing ©iStockphoto.com/Fotofrank
39 illustration: smell Morris/Maisto, 9/e p. 100
40 illustration: taste Morris/Maisto, 9/e p. 101
41 standing on hand ©iStockphoto.com/Get4Net
42 massage ©iStockphoto.com/Stills
43 brain ©iStockphoto.com/Henrik Jonsson
43 back pain ©iStockphoto.com/Mads Abildgaard
43 acupuncture ©iStockphoto.com/TouchPhotography
45 rubber bands ©iStockphoto.com/Shag Photo
46 architectural background ©iStockphoto.com/Jorge Delgado
46 berries ©iStockphoto.com/Amriphoto
46 flea market table ©iStockphoto.com/ROMA-OSLO
46 rubber bands ©iStockphoto.com/Shag Photo
47 yellow spider on yellow flower ©iStockphoto.com/Dmitry Galanternik
48-50 Gestalt principles animations Derek Borman
51 tangled roots ©iStockphoto.com/avi T
52 Open Your Book - textbook cover Shutterstock
52 Open Your Book - textbook background From Ciccarelli, Psychology, 1/e pp. 213-214
52 Open Your Book - open textbook From Ciccarelli, Psychology, 1/e pp. 114-115
53 icon: helmet ©istockphoto.com/Li Shen Jun
53 spyglass ©iStockphoto.com/On The Spot Images
54 night cityscape ©iStockphoto.com/adamkaz
54 spyglass ©iStockphoto.com/On The Spot Images
55 road w/ trees ©iStockphoto.com/pixonaut
55 spyglass ©iStockphoto.com/On The Spot Images56 man mountains in distance ©iStockphoto.com/Sportstock56 spyglass ©iStockphoto.com/On The Spot Images57 tree ©iStockphoto.com/Maksym Bondarchuk57 spyglass ©iStockphoto.com/On The Spot Images57 road with tree ©iStockphoto.com/AVTG58 flat rocks to water ©iStockphoto.com/Arnau Design58 spyglass ©iStockphoto.com/On The Spot Images59 sphere ©iStockphoto.com/Sean Gladwell59 spyglass ©iStockphoto.com/On The Spot Images60 kids looking out window ©iStockphoto.com/Marina Dyakonova60 lamb ©iStockphoto.com/Life on White60 spyglass ©iStockphoto.com/On The Spot Images60 goose ©iStockphoto.com/Online Creative Media60 mountains with lake ©iStockphoto.com/Studio 9Fifteen60 mountains with meadow ©iStockphoto.com/browndogstudios60 mountains ©iStockphoto.com/Edward Shnekendorf61 binoculars ©iStockphoto.com/Alex Staroseltsev62 illustration: location of sounds Morris/Maisto, 9/e p. 11364 illustraton: perceptual illusions Morris/Maisto, 9/e p. 11565 diverse people with different reactions ©iStockphoto.com/ALiJA67 topbar: wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt67 topbar: cactus ©istockphoto.com/Lee Daniels67 topbar: wooden board ©istockphoto.com/andynwt69 carousel ©iStockphoto.com/Monique Harris71 smokestacks ©iStockphoto.com/AVTG73 topbar: helmets ©istockphoto.com/Li Shen Jun73 topbar: athletic field ©istockphoto.com/Jamie Otterstetter74 icon: classic studies car ©istockphoto.com/Brian Sullivan74 topbar: chrome & license plate ©istockphoto.com/Grafissimo74 topbar:red shiny car background ©istockphoto.com/Jon Helgason75 flag color afterimage From Ciccarelli, Psychology, 2/e p. 10078 topbar: wanted sign Charlie Levin, adapting wooden board image from ©istockphoto.com/andynwt78 topbar: cactus ©istockphoto.com/Lee Daniels78 topbar: wooden board ©istockphoto.com/andynwt78 text messaging ©iStockphoto.com/Freeze Frame Studio, Inc.79 topbar: helmets ©istockphoto.com/Li Shen Jun79 topbar: athletic field ©istockphoto.com/Jamie Otterstetter