Chapter Four Outline
4.1 Sensory Processes The First Step
Question 4.1: In general, how do sensory systems function?
Learning Objective 4.1.1 – Describe how our senses act as biological transducers and data reduction systems; and differentiate between the processes of sensation and perception.
Learning Objective 4.1.2 – Explain the process of transduction by the sensory receptor organs; describe the field of psychopsychics and the concept of absolute thresholds; and discuss the data reduction processes of sensory adaptation, analysis, and coding, including a description of the Blakemore and Cooper study and definitions of the following terms: perceptual features, feature detectors, the pop-out effect, difference thresholds, and phosphenes.
Learning Objective 4.1.3 – Describe sensory localization; and explain how this process is making it possible to artificially restore sight, hearing, and the other senses.
4.2 Vision Catching Some Rays
Gateway Question 4.2: How does the visual system function?
Learning Objective 4.2.1 – Discuss the basic dimensions of light and vision, including the concepts of the visual spectrum, hue, saturation, and brightness; describe the functions of the cornea, lens, retina, and photoreceptors; and explain how the eye focuses light by comparing its function to that of a camera.
Learning Objective 4.2.2 – Describe the four vision problems of hyperopia, myopia, astigmatism, and presbyopia and their treatment.
Learning Objective 4.2.3 – Discuss the functions of the rods and cones; and explain how the brain compensates for the blind spot.
Learning Objective 4.2.4 – Identify which photoreceptors specialize in color vision, visual acuity, and daylight vision and which type specializes in peripheral vision, night vision, seeing black and white, and detecting movement; discuss visual acuity, including the importance of the fovea in the process, what constitutes normal visual acuity, and how visual acuity is measured; describe the condition known as tunnel vision; and explain how one can attain the best night vision.
Learning Objective 4.2.5 – Describe how color sensations are produced by comparing the trichromatic and opponent-process theories of color vision, including explanations of the role of iodopsin in the trichromatic theory and how afterimages are formed in the opponent-process theory.
Learning Objective 4.2.6 – Describe the types of color blindness and color weakness and the proportion of individuals who have these conditions; and explain how these conditions are measured using the Ishihara Test.
Learning Objective 4.2.7 – Explain what happens during dark adaptation, including the importance of rhodopsin; and describe how long dark adaptation takes to occur, how quickly dark adaptation can be completely wiped out, and how the process of dark adaptation can be speeded up.
4.3 Hearing Good Vibrations
Gateway Question 4.3:
What are the mechanisms of hearing?
Learning Objective 4.3.1 – Explain the stimulus for hearing using the terms compression, rarefaction, frequency, and amplitude; and describe the location and function(s) of the following parts of the ear: a. pinna; b. eardrum (tympanic membrane); c. auditory ossicles; d. oval window; e. cochlea; f. hair cells; g. stereocilia; and h. organ of Corti.
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Learning Objective 4.3.2 – Explain how higher and lower tones are detected, using the place theory and the frequency theory, and describe why some people may develop the “Hunter’s notch.”
Learning Objective 4.3.3 – Discuss the two basic types of hearing loss, conductive and sensorineural, and the common form of sensorineural hearing loss known as noiseinduced; identify the decibel levels of sounds that can cause temporary and permanent hearing loss; and describe the methods of artificial hearing used for the different types of loss.
4.4 Smell and Taste The Nose Knows When the Tongue Can’t Tell
Gateway Question 4.4: How do the chemical senses operate?
Learning Objective 4.4.1 – Identify the two chemical senses, and explain their importance in everyday life.
Learning Objective 4.4.2 – Using the lock and key theory of olfaction, explain how various odors are detected by the smell receptors; and describe the conditions of anosmia and dysosmia, and what factors can cause them.
Learning Objective 4.4.3 – Discuss the sense of taste, including the five taste sensations, the sensitivity of humans to these tastes, the location and functions of the taste buds, and how taste is affected by smell, texture, temperature, and pain.
4.5 The Somesthetic Senses Flying by the Seat of Your Pants
Gateway Question 4.5: What are the somesthetic senses?
Learning Objective 4.5.1 – List the three somesthetic senses, their purposes, and the locations of their sense receptors.
Learning Objective 4.5.2 – List the five sensations produced by the skin receptors; and explain why certain areas of the body are more sensitive to touch than other areas are.
Learning Objective 4.5.3 – Differentiate between the warning and reminding systems regarding pain messages and the nerve fibers involved; and describe the condition known as congenital pain insensitivity.
Learning Objective 4.5.4 – Discuss Melzack and Wall’s gate control theory and how it explains the painkilling effects of acupuncture; and describe how the neuromatrix created by the brain explains the occurrence of phantom limb pain.
Learning Objective 4.5.5 – Discuss the use of counterirritation as a pain control technique, and explain how the three psychological factors of anxiety reduction, control, and attention can be used to reduce pain.
Learning Objective 4.5.6 – Discuss the vestibular system including the parts of the inner ear involved, how the sensory conflict theory explains motion sickness, and ways to minimize this motion sickness.
4.6 Perception The Second Step
Gateway Question 4.6: In general, how do we construct our perceptions?
Learning Objective 4.6.1 – Explain how we construct our perceptions, why perceptual construction is considered a learned ability, and why perceptual misconstruction often occurs; describe how the illusion of the Ames room is created; differentiate between illusions and hallucinations; and discuss the Charles Bonnet syndrome and the process of reality testing.
Learning Objective 4.6.2 – Explain bottom-up and top-down processing, and identify examples of each type of processing.
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Learning Objective 4.6.3 – Describe figure-ground organization, including reversible figures and camouflage patterns; and explain why figure-ground perception is probably an inborn ability.
Learning Objective 4.6.4 – Describe and identify examples of the Gestalt organizing principles of nearness, similarity, continuity, closure, contiguity, and common region.
Learning Objective 4.6.5 – Explain the concept of perceptual hypothesis; and describe what is meant by ambiguous stimuli and impossible figures.
Learning Objective 4.6.6 – Describe the perceptual constancies of size, shape, and brightness; and explain the difference in native and empirical perceptions.
4.7 Selective Attention Tuning In and Tuning Out
Gateway Question 4.7: Why are we more aware of some sensations than others?
Learning Objective 4.7.1 – Discuss the process of selective attention; and explain how the “seat-of-the-pants phenomenon” and “cocktail party effect” are related to this process.
Learning Objective 4.7.2 – Explain how inattentional blindness happens by including a description of the research study by Simons and Chabris and examples of how inattentional blindness occurs while driving; and identify the types of stimuli that tend to be attention getting.
4.8 Depth Perception What If the World Were Flat?
Gateway Question 4.8: How is it possible to see depth and judge distance?
Learning Objective 4.8.1 – Describe the perceptual ability of depth perception, including how we use this ability in everyday life; and discuss the visual cliff experiments that show that depth perception is present soon after birth.
Learning Objective 4.8.2 – Explain how depth perception depends on the binocular cues of retinal disparity and convergence; and define stereoscopic vision.
Learning Objective 4.8.3 – Explain how one’s depth perception depends on the monocular cue of accommodation.
Learning Objective 4.8.4 – Describe and identify examples of the following monocular, pictorial depth cues: a. linear perspective; b. relative size; c. height in the picture plane; d. light and shadow; e. overlap; f. texture gradients; g. aerial haze; h. motion parallax.
Learning Objective 4.8.5 – Describe the moon illusion and how it is explained by the apparent-distance hypothesis.
4.9 Perceptual Learning Believing Is Seeing
Gateway Question 4.9: How is perception altered by expectations, motives, emotions, and learning?
Learning Objective 4.9.1 – Explain how suggestion, motives, emotions, attention, and prior experience combine in various ways to create perceptual sets, or expectancies; and describe how prior experience tends to be the main reason for the other-race effect.
Learning Objective 4.9.2 – Explain how personal motives, values, and cultural differences can affect one’s everyday perception and evaluation of objects and events and even alter one’s attention to specific details.
Learning Objective 4.9.3 – Explain how perceptual learning influences the top-down organization and interpretation of sensations and leads to the creation of perceptual habits.
Learning Objective 4.9.4 – Explain how the Müller-Lyer illusion is related to perceptual learning, linear perspective, and size–distance invariance relationships; and describe the research conducted with the Zulu villagers using the Müller-Lyer illusion.
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4.10
Extrasensory Perception Do You Believe in Ghosts?
Gateway Question 4.10: Is extrasensory perception possible?
Learning Objective 4.10.1 – Define the terms extrasensory perception, parapsychology, and psi phenomenon; and describe the purported psychic abilities of clairvoyance, telepathy (including mediumship), precognition, and psychokinesis.
Learning Objective 4.10.2 – Discuss the research on parapsychology, including J.B. Rhine’s early research with Zener cards; and explain how parapsychology studies have been plagued by fraud, poorly designed experiments, and chance and inconsistency.
Learning Objective 4.10.3 – Discuss the implications of the more carefully controlled recent ESP experiments; and explain what it would take to scientifically demonstrate the existence of ESP.
4.11 Psychology in Action: Pay Attention! Becoming a Better Eyewitness to Life
Gateway Question 4.11: How can I learn to perceive events more accurately?
Learning Objective 4.11.1 – Explain why eyewitness testimony tends to be surprisinglyunreliable; and describe the factors that tend to damage the accuracy of eyewitness testimony.
Learning Objective 4.11.2 – Explain why habituation occurs; and describe the perceptual styles of people that Abraham Maslow said perceived themselves and others with unusual accuracy.
Learning Objective 4.11.3 – Explain how people can maintain and enhance perceptual awareness and accuracy by making a conscious effort to pay attention; by understanding how motives and emotions influence perceptions; and by employing the following approaches: a. reality testing, b. dishabituation, c. breaking perceptual habits, d. broadening frames of reference, and e. avoiding the development of perceptual sets.
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Discussion Topics
One-Minute Motivator 4.1: Transduction
A child’s battery-operated toy musical instrument can serve as an example of a transducer. Pressing a key converts mechanical energy into an electrical current that activates a mechanical device that makes a musical sound.
One-Minute Motivator 4.2: Sensory Waves
Drop a pebble in a dish of water. Watch the compression and refraction of the waves If you use a clear glass pie plate, this can be shown to larger classes with an overhead projector.
One-Minute Motivator 4.3: Hearing in Man/Woman vs. Beast
Bring a dog whistle and a dog to class. First have the class observe the behavioral response of a fellow student to “a very soft whistle.” You may have false positives, so also fake blowing the whistle. Then bring in the dog and show the canine response.
One-Minute Motivator 4.4: Smell Habituation
Ammonia, rotten eggs, vinegar and other smelly materials can be brought to class. Students rate the smell at the start of class and every 10 minutes after, and should quickly experience olfactory adaptation (habituation).
One-Minute Motivator 4.5: Gating Pain
Ask students to raise their hands if they are currently having a headache or other body pain. Then, ask them to provide some counterirritation. They will usually report this reduces the experience of the headache or body pain. This shows the influence of the reminding system and ability to “gate” the pain.
One-Minute Motivator 4.6: Perceptual Hypotheses
Develop a five-minute video of close-ups of common objects. Show each close-up and have students guess what the object is. Then show the entire object. Discuss how perceptual hypotheses and figure/ground processes explain the way objects are normally perceived.
One-Minute Motivator 4.7: Depth Perception
Depth cues can be demonstrated with a series of slides or transparencies. Ask students to name each cue and explain how it contributes to perceived depth.
One-Minute Motivator 4.8: Perceptual Learning
How has perceptual learning affected your ability to safely drive a car? For example, what do you pay attention to at intersections? Where do you habitually look as you are driving?
One-Minute Motivator 4.9: Reality Testing
Because perceptions are reconstructions or models of external events we should all engage in more frequent reality testing. Can you think of a recent event when a little reality testing would have saved you from misjudging a situation?
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One-Minute Motivator 4.10: Perceptual Adaptation
Ask students to use a mirror to write their names, copy a geometric design, etc. Ask an observing student to note the nature of the errors made as his/her partner adapts to this new perceptual world.
One-Minute Motivator 4.11: Perceptual Comparisons
Send three students outside to serve as subjects. Put three others in front of the class. Invite one subject in and ask the person to estimate the height of the middle student. Ask the middle student to remain; ask two other students to come up to the front. Invite another subject inside. The guesses should change, depending on the height of the other two students as well as the height of the subject.
Broadening Our Cultural Horizons 4.1: Culture Differences in Sensory Channels
Do various cultures emphasize different sensory channels to a greater or lesser degree? For example, do some cultures place more emphasis on touch, taste, or smell than North Americans do? What does the American preoccupation with television tell us about our culture? The French reputation for cooking? The Italian tendency to touch a person when talking to her or him?
Broadening Our Cultural Horizons 4.2: Cultural Differences in Pain Management
Various cultures have different approaches to pain management. Some groups suggest that pain should be ignored; others acknowledge pain but suggest specific ways to deal with it. What did the “mini-culture” of your family suggest? If you suddenly feel pain in your chest, what has your culture taught you to do? Are these behaviors adaptive or maladaptive?
Broadening Our Cultural Horizons 4.3: Perceiving Letters from Different Languages
Ask students skilled in languages other than English to share with the class the alphabet of the language and a few key words. Using Russian, Japanese, or Chinese characters is especially effective. Discuss how meaningless the characters or words may seem at first. Rewrite the letters each day on the chalkboard. After a few sessions, the words should become meaningful. Remind students that English appears just as meaningless at first to the non-English speaker as these characters or words appear to the English speaker.
Value Clarification 4.1: All Public Communications Should be Available to People With Sensory Limitations
All signs for public facilities should be written in Braille and positioned low enough to touch. All traffic signals should have geometric shapes in addition to colors, to help people who are colorblind (e.g. square for green, diamond for yellow, and circle for red.) All presidential and political press conferences should be required to provide a signing interpreter.
Value Clarification 4.2: Divided Attention is Not Bad
It should be up to students to decide whether they can listen to lecture and do other activities (like other homework) at the same time.
Value Clarification 4.3: Surgery for Vision is Just Vain
People who have their vision surgically corrected are just being vain.
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Value Clarification 4.4: Deaf People Should Have Their Hearing Corrected
Deaf people who can regain hearing through the use of hearing aids, and even cochlear implants, should do it.
Value Clarification 4.5: Ban Loud Music!
Rock musicians should be prohibited from playing music at damaging decibel levels. Portable MP3 players like iPods, with headphones should be taken off the market because of potential misuse by children and damage to the children’s ears.
Value Clarification 4.6: People With Sensory Impairments Should Not Drive
A person with impaired depth perception should not be allowed to drive a car. Neither should deaf people or colorblind and color deficient individuals.
Value Clarification 4.7: Don’t Make Too Much of Pain
When children fall and hurt themselves (not seriously) the best policy is to tell the child to ignore the pain.
Value Clarification 4.8: Parents are Out of Touch With Their Teenagers
It is impossible for parents to really understand how their teenage children perceive the world.
Value Clarification 4.9: Eyewitness Testimony is Problematic
Eyewitness testimony doesn’t have a big impact on the verdict if the physical evidence is not there. Therefore, eyewitness testimony alone should never be allowed to determine the outcome of a trial. Further, all juries should be instructed about the limitations of eyewitness testimony.
Value Clarification 4.10: Psychics are Phonies
Apparent examples of ESP are really based on coincidence. “Psychics” and other paranormal services prey on the uninformed.
Classroom Activities
Exercise 4.1: Our Sensory System
To demonstrate the idea that information is continuously flowing into our sensory system, but that it is not always attended to, play a tape of a waterfall or surf during your lecture. Ask students whether they feel they need to pay attention to information for it to trigger some kind of sensory response.
Exercise 4.2: Archimedes Spiral
The senses do not simply mirror external “reality,” they shape our experiences in a multitude of ways. The Archimedes spiral can produce a powerful distortion of sensory experience, and thus bring home the fact that what we take for “reality” is greatly affected by the functioning of sensory systems.
You may be able to find a digital image of Archimedes spiral, but you can also make your own physical version of it. To construct an Archimedes spiral, obtain a phonograph turntable. (The author’s is a child’s phonograph with the tone arm missing. It was purchased from a thrift store for less than a dollar.) Cut a large circle of white
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posterboard (roughly 12-15 inches in diameter). Make a hole in the middle of the posterboard disk so that it can be placed on the turntable like a phonograph record. Leave the hole small so that the disk will remain attached to the turntable when the phonograph is laid on its side for the class to see. Use a black felt-tip marker to draw a wide, bold spiral from the edge to the center of the disk. When the disk is turning, the spiral may appear to be collapsing in toward the center, or expanding outward, depending on how it is drawn. Either type of spiral will work, but the inward-moving spiral tends to produce a stronger effect. It would be interesting to make one of each to see how each works. Set the turntable on its side on the edge of a desk or table so that the cardboard disk can rotate freely and be seen by the class. Set the turntable at its lowest speed. Have students focus on the center of the spiral for at least one minute. Then ask them to look immediately at some other object (a clock on the wall or your face, for example). If the collapsing spiral has been used, a figural after-effect occurs in which the object viewed after fixation appears to be expanding.
After the “oohs” and “ahs” die down, point out that a traditional test of the reality of an event is its consensual validation. If several people have the same experience simultaneously, it is thought to be “real.” If only one has the experience, it may be considered a hallucination. The question becomes, then, did the clock (or your face) actually change size, or did it not? In terms of subjective experience, an entire classroom full of people could swear in court that it did, yet in reality it did not.
Exercise 4.3: Eye vs. Camera
If you know a camera buff or a dynamic photography instructor, ask to have a camera taken apart for the class. Point out the parts that function in a way similar to parts of the eye.
Exercise 4.4: Pupil Reaction
Ask students in pairs to observe each other’s pupils. Flip a coin to select the “subject.” Darken the room for a few minutes. Turn on the lights and have students estimate how many seconds it takes their partner’s pupils to return to their original degree of constriction.
Exercise 4.5: Ishihara Plates
Although the reproduction of the Ishihara plates in the text is not adequate for formal testing, it is sufficiently accurate to allow detection of color-blind or color-weak students in the class. Usually such students can provide amusing anecdotes about their discovery of, or life with, impaired color vision.
Exercise 4.6: Smell and Taste
As the text points out, “flavor,” as we experience it subjectively, is actually a combination of olfaction and gustation. This can be demonstrated relatively easily. Bring to class some apple, potato, and onion cut into tiny bits. Have a student volunteer taste bits of each while blindfolded. Discriminating between different foods should be simple in this condition. Next, test the blindfolded volunteer while he or she pinches the nostrils closed. With more olfactory cues reduced, correctly identifying the food bits should be more difficult (although not impossible). Even if they correctly identify the foods in the second test, subjects will usually report greater difficulty. Typically, they must rely more on texture than on “taste” when olfactory cues are reduced.
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Exercise 4.7: Cutaneous Two-Point Threshold
This handout is designed to help students understand how different parts of the body are more and less sensitive to touch using Handout 4.1. To carry out this exercise you need a subject and an experimenter and a device with two points. The two-point instrument could be a divider from a geometry set or some similar item that has two points which can be set at varying distances apart with some way to measure that distance.
This exercise can be done as a demonstration with several students selected to be subjects or by dividing up the whole class into pairs with each one alternating as subject and experimenter. The latter would require a large number of two-point instruments. An alternative would be to open small paperclips and use the ends as the pointers.
The procedure for this activity is as follows:
1. Identify the subjects and experimenters. If the class is paired, each couple can determine this. Have each student use a ruler with cm. to draw a line on one of their fingers, or the back of their hand, or on part of their arm.
2. Blindfold the subject to be tested.
3. Provide the experimenter, or the whole class, with the data sheet which indicates the area of the skin surface to be tested and the type of test to make. The experimenter will touch the surface of the skin with one point or two, altering the distance between the points with each trial to move the points closer together or further apart. The subject will respond with “one” or “two” when each contact is made.
4. Record all responses until the subject can no longer distinguish between one and two points on successive trials.
5. Have students record the responses for each subject. If the students are working in pairs, the experimenter will record each trial. After completing the trials, the two will change places and repeat the procedure. Provide students with enough data sheets for all subjects to be tested.
6. After all testing is completed, collect the data and work out the thresholds for each part of the skin surface tested.
7. Students should note and discuss differences found among students and differences from one part of the body to the other.
8. Ask students to explain why these differences occur in different parts of the body.
(based on a demonstration by Dr. William C. Titus, Arkansas Tech University)
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Exercise 4.8: Temperature is Relative
There is an age-old demonstration that students can do easily to demonstrate that there are separate receptors for hot and cold and that temperature sensations are relative. Prepare three containers of water: one cold, one warm, and the third lukewarm. None should be extreme, not too cold or too hot. Have students put one hand into the cold water and the other into the warm. They should observe that one hand will feel cold and the other warm and also notice that the cold or warm feeling occurs mostly at the water line, where air and water meet. This is the only place on the skin where a comparison of air and water temperature can be experienced. The relative difference is what is reported as cold or warm. After being held in the containers for a few minutes, both hands should be put in the container of lukewarm water. Students will notice that the hand that was in cold water will feel warm, and the hand in warm water will now feel cold. Once again, a comparison of the sensations before and after is what is noted by the brain.
Exercise 4.9: Selective Attention
In almost every classroom there are weak background stimuli that can be used to demonstrate selective attention. The buzzing of neon lights, the hum of an air conditioner, the drone of street noise any of these can be used to show that a stimulus may be present but not consciously perceived until attention is shifted to it. Simply stop in midsentence and call attention to one of these stimuli.
Exercise 4:10: Mapping the Eye and Ear
Have students complete blank maps of the eye and ear. Blank maps can be found on the Internet. Instruct your students to fill in the names of the structures including the functions of each. In addition, have students indicate the path that sensory information takes through the auditory and visual systems.
Exercise 4.11: Perceptual Constancy
This demonstration requires a bit of construction. Obtain a cardboard carton (a halfgallon ice cream carton is about right). Paint the carton flat black. Punch two small holes in the bottom of the carton, one in the center and one near the rim. Place a flashlight inside, facing the bottom, and stuff crushed newspaper around it for support. Leave a space between the lens of the flashlight and the bottom of the carton so that both holes can be lighted.
Cover the center hole with opaque tape. Turn off the room lights and turn on the flashlight. Face the bottom of the carton toward the class and roll it from left to right across a tabletop. The rim light will describe a series of inverted half-circles. Next, uncover the center hole, cover the rim hole, and roll the carton again. The center light will make a straight line from left to right. You would expect, if the carton is rolled again with both holes uncovered, that the two patterns (half-circles and a straight line) would simply be superimposed on one another. Not so! Instead, the class will see a more unified and sophisticated pattern: the rim light will appear to move in complete circles around the center light. Students should be asked to account for this perceptual organization in terms of principles described in the text.
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Exercise 4.12: Convergence
For a simple illustration of convergence, have students focus on a distant point and then bring a finger up into the line of sight. The finger will appear “transparent” because the line of sight is nearly parallel. If students then look directly at the finger, it will once again become “solid” (convergence). A variation on this (which also illustrates retinal disparity and fusion) involves again fixating on a distant point. This time the tips of the index fingers of both hands should be brought together in the line of sight, about twelve inches from the eyes. Students should see a small “sausage” forming and disappearing between their fingertips as the two retinal images overlap.
Exercise 4 13: Müller-Lyer Illusion
Students often underestimate the effect of the Müller-Lyer illusion because they are so familiar with it. To demonstrate it in class, on a sheet of paper draw a horizontal line several inches long and place an “arrowhead” on one end and a “V” on the other. Be sure not to center the line within the borders of the page. Duplicate this figure and distribute it to the class. Ask the students to mark the spot that they think is the center of the horizontal line (without trying to correct for the illusion). Now fold the page so the tips of the horizontal line are matched up (to do this they will have to hold the paper up to the light), and crease the paper at the fold. Now ask them to unfold the page and compare the crease with the mark they made. The majority of the students will have erred in their bisection due to the illusion. This is a good launching point for a discussion of illusions
Exercise 4 14: Selective Attention
The role of contrast in selective attention can be demonstrated by having two students read aloud simultaneously from different books. First this should be done by two students of the same sex who have similar voices. Then it should be done by a male and female pair. The class’ ability to selectively attend to one message or the other will be greatly enhanced in the second condition.
Exercise 4 15: Stroop Effect Perception/Attention
The two exercises outlined in this section should help students understand some aspects of perception that may lead to further discussion and investigation.
In 1935 J. R. Stroop developed an experiment, which now bears his name, on how we process conflicting sensory data. It is called the Stroop Effect. He found that conflicting sensory data slows down the process of perception and increases the chance of error. With a small amount of preparation you can do the experiment in class.
This exercise may be done as a classroom demonstration or as an all-class project. If you choose the former, select several subjects (about five would be sufficient) and ask them to leave the room. You will then bring them back, one at a time, and test them in front of the class, who will be observers and recorders. The latter method, involving the whole class, would require a bit more work to prepare but should pay off in greater student interest. You would pair up the students, having one be the subject and the other the experimenter. The roles could be reversed to test the bi-directional effect. (Handout 4.2)
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Instructions for Handout 4.2:
Procedure: This exercise should be carried out as follows:
1. Prepare three word-color sheets. The words should be spaced equally on both the horizontal and vertical dimensions. The list and arrangement are found at the end of this exercise. Each of the sheets will be a list of four colors: yellow, blue, green, and red. They will be presented in identical order but in different ways.
a. List #1: This list will be done in black or blue ink. All will be the same color.
b. List #2: This list will not be words but color patches. Each patch will be the color of the word on the list. These patches can be done with crayons or markers, and should be small rectangles of color with no words.
c. List #3: The words on this sheet should be the same as on List #1, except that the words should be printed in color. The color used should always be different from the color named in the word.
2. If this is to be a classroom demonstration, prepare your subjects, experimenters, and recorders. Otherwise, pair up the students in the class and identify the subjects and experimenters, who will also act as recorders. Each experimenter will need a watch, which will measure seconds for timing the subject. The three sheets should be placed face down in front of the subject in order of presentation. Reading each list will constitute a trial. In each case, the subject will be instructed to read the list from left to right from the top line down, as quickly as possible. When finished, the subject should say, “done.” The experimenter will time the reading of each list and note it on the data sheet.
3. Present List #1 and ask the subject to read the words in order. When presenting List #2, ask the subject to name the color on the patches in the same order as before. For List #3 ask the subject to name the color of the ink in which each word is printed.
4. Collect the data for all subjects and work out a class average for each of the three lists. If the Stroop Effect has occurred, you should find that the subjects took about the same amount of time to read Lists #1 and #2, and longer for #3.
If you have time, reverse the roles of experimenter and subject and repeat the experiment. The only difference would be in reading List #3. The new subject would be asked to read the words on the third list instead of identifying the color of the word. This may provide a different average time when compared with the average time for the first subjects.
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Some questions for discussion:
1. Was the Stroop Effect evident? Explain how it manifested itself.
2. How can you account for the differences in average time?
3. Did the change in the reading of List #3 produce a different average time? How great was the difference? How could it be explained?
(based on a demonstration by William C. Titus, Arkansas Tech University)
Exercise 4 16: Eyewitness Testimony
For a dramatic and time-honored demonstration of the inaccuracies of eyewitness testimony, arrange for a confederate to “make a scene” in class. Ideally, the confederate should wear unusual or distinctive clothing (different colored socks, an outlandish hat, etc.). The confederate should charge into class, ask loudly if you are “Professor (your name),” “douse” you with a bucket full of paper clippings, and then run out. Immediately after, ask the class to write a description of your “attacker.” Then compare details of the descriptions. For an interesting twist, tell students to be sure to include the color of the visitor’s socks in their descriptions. In this variation, of course, the confederate wears no socks!
Exercise 4.17: Mental Telepathy
Provide students with apparent examples of “mental telepathy.” In groups have them decide how the following occurrences could be mere coincidences:
“I suddenly woke up and knew that something tragic had happened to my mother. That morning I received a call that she had died at that precise hour.”
“My sister and I live 3,000 miles apart. We have never visited each other’s homes. I didn’t know what to buy her for a holiday gift but somehow knew she would like a specific set of towels. I was not surprised to learn that she had already bought a shower curtain of that brand for her bathroom and needed the towels I sent to complete the décor.”
Exercise 4 18: It’s in the Cards
Procedure:
1. Distribute a response sheet (Handout 4.3) to each member of the class and explain how it is to be used.
2. Shuffle the deck of cards thoroughly in full view of the class and place the deck face down on the table.
3. Pick up one card at a time, look at it carefully for about two seconds, and place it face down on a new pile. Do not let students see the face of the card. While concentrating on the card, try to shut out any distracting thoughts. If you are preoccupied with running the demonstration, have a student, prepared beforehand, do the telecommunicating.
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4. Give the students time to write down on their data sheets the symbol which they think you saw on the card. Note on your own record sheet what the symbol was. Proceed through the deck in the same way.
5. After completing a trial (one run through the deck), shuffle the cards thoroughly and go through the stack again. Repeat this until you have completed five trials, being sure to shuffle the cards before each one. Also, be sure you have kept an accurate record of each card for each trial run.
6. After the fifth run through the deck, give the students the correct listing of cards so they can score their sheets.
7. Ask the students to total the number of correct responses for each of the five trials. They can work out the percentage for each run by dividing the number right by 25 and multiplying by 100.
8. Then ask them to total the number right for all five trials. Divide this total by 125 and multiply by 100 to get a percentage for the whole experiment.
Discussion:
Ask the students to discuss their findings. They should first determine what they could expect to score by chance alone, i.e., by guessing. Then they can compare their scores with the chance score to see if they did as well, poorer, or better.
1. Do those who did better have ESP?
2. In this case, do they have the power of telepathy?
3. What would happen if you did it many more times?
4. Of what value is it to do better than chance?
Role-Playing Scenario 4.1: Imagine That You Have Lost One of Your Major Senses
Which sense would be most difficult to lose? Why? Describe this situation as if it had actually happened to you. Next, imagine that you have lost only the ability to feel heat, cold, or pressure. How would you act? How would you cope?
Role-Playing Scenario 4.2: Deafness
Place yourself in each of the following scenarios:
a. You are 40 years old, a college professor, and have never been able to hear. You lip-read and know American Sign Language. Describe your life and the reactions others have had to you.
b. You are 40 years old, a college professor, and recently lost your hearing due to an infection that destroyed the structures of the inner ear. Describe your life and the reactions others have had to you.
Role-Playing Scenario 4.3: Expanding Your Senses
You suddenly become able to hear sounds above 20 kilohertz and to see infrared and ultraviolet light. Try to explain what you are experiencing to a person with normal sensory thresholds.
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Role-Playing Scenario 4.4: Eyewitness Testimony
Ask a student to run through class and grab an item off a desk in the front (your purse, your wallet, your notes, etc.). Try to express anger and surprise. While the student remains outside the class, choose a witness to question. Appoint two other students as inquisitors. These questioners should try to find out what the witness knows about the crime and which of the details provided by the witness are most reliable. Conclude by bringing the culprit back into view and discuss any inaccuracies in the witnesses’ testimony.
Role-Playing Scenario 4.5: ESP Research Should be Supported
Set up a debate of the proposition that “ESP is a confirmed sensory process and research in this area should receive federal financial support.” Select two students to serve as the advocates for the proposition; select two students to oppose this statement.
Role-Playing Scenario 4.6: Lacking Depth Perception
Ask a student to mime the role of a person who lacks depth perception and who sees the world as if it were a flat surface.
Key Terms
Absolute threshold The minimum amount of physical energy necessary to produce a sensation.
Accommodation Changes in the shape of the lens of the eye.
Apparent-distance hypothesis An explanation of the moon illusion stating that the horizon seems more distant than the night sky.
Astigmatism Defects in the cornea, lens, or eye that cause some areas of vision to be out of focus.
Binocular depth cues Perceptual features that impart information about distance and threedimensional space which require two eyes.
Bottom-up processing Organizing perceptions by beginning with low-level features.
Brightness constancy The apparent (or relative) brightness of objects remains the same as long as they are illuminated by the same amount of light.
Color blindness A total inability to perceive colors.
Color weakness An inability to distinguish some colors.
Conductive hearing loss Poor transfer of sounds from the eardrum to the inner ear.
Cones Visual receptors for colors and daylight visual acuity.
Dark adaptation Increased retinal sensitivity to light.
Depth cues Features of the environment and messages from the body that supply information about distance and space.
Depth perception The ability to see three-dimensional space and to accurately judge distances.
Difference threshold The minimum difference between two stimuli that is detectable to an observer.
Dishabituation A reversal of habituation.
Extrasensory perception (ESP) The purported ability to perceive events in ways that cannot be explained by known capacities of the sensory organs.
Figure-ground organization Organizing a perception so that part of a stimulus appears to stand out as an object (figure) against a less prominent background (ground).
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Gate control theory Proposes that pain messages pass through neural “gates” in the spinal cord.
Gustation The sense of taste.
Habituation A decrease in perceptual response to a repeated stimulus.
Hair cells Receptor cells within the cochlea that transduce vibrations into nerve impulses.
Hallucination An imaginary sensation such as seeing, hearing, or smelling something that does not exist in the external world.
Hyperopia Difficulty focusing nearby objects (farsightedness).
Illusion A misleading or misconstructed perception.
Inattentional blindness A failure to notice a stimulus because attention is focused elsewhere.
Kinesthetic senses The senses of body movement and positioning.
Lock and key theory of olfaction Holds that odors are related to the shapes of chemical molecules.
Monocular depth cues
Perceptual features that impart information about distance and threedimensional space which require just one eye.
Müller-Lyer illusion Two equal-length lines tipped with inward or outward pointing V’s appear to be of different lengths.
Myopia Difficulty focusing distant objects (nearsightedness).
Noise-induced hearing loss Damage caused by exposing the hair cells to excessively loud sounds.
Olfaction The sense of smell.
Opponent-process theory Theory of color vision based on three coding systems (red or green, yellow or blue, black or white).
Organ of Corti Center part of the cochlea, containing hair cells, canals, and membranes.
Frequency theory Holds that tones up to 4,000 hertz are converted to nerve impulses that match the frequency of each tone.
Perception The mental process of organizing sensations into meaningful patterns.
Perceptual construction A mental model of external events.
Perceptual expectancy (or set) A readiness to perceive in a particular manner, induced by strong expectations.
Perceptual features Basic elements of a stimulus, such as lines, shapes, edges, or colors.
Perceptual habits Ingrained patterns of organization and attention that affect our daily experience.
Perceptual hypothesis An initial guess regarding how to organize (perceive) a stimulus pattern.
Perceptual learning Changes in perception that can be attributed to prior experience; a result of changes in how the brain processes sensory information.
Peripheral (side) vision Vision at the edges of the visual field.
Pictorial depth cues Monocular depth cues found in paintings, drawings, and photographs that impart information about space, depth, and distance.
Place theory Theory that higher and lower tones excite specific areas of the cochlea.
Presbyopia Farsightedness caused by aging.
Psi phenomena Events that seem to lie outside the realm of accepted scientific laws.
Psychophysics Study of the relationship between physical stimuli and the sensations they evoke in a human observer.
Reality testing Obtaining additional information to check on the accuracy of perceptions. Reminding system Pain based on small nerve fibers; reminds the brain that the body has been injured.
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Retina The light-sensitive layer of cells at the back of the eye.
Rods Visual receptors for dim light that produce only black and white sensations.
Run of luck A statistically unusual outcome (as in getting five heads in a row when flipping a coin) that could still occur by chance alone.
Selective attention Giving priority to a particular incoming sensory message.
Sensation A sensory impression; also, the process of detecting physical energies with the sensory organs.
Sensorineural hearing loss Loss of hearing caused by damage to the inner ear hair cells or auditory nerve.
Sensory adaptation A decrease in sensory response to an unchanging stimulus.
Sensory analysis Separation of sensory information into important elements.
Sensory coding Codes used by the sense organs to transmit information to the brain.
Sensory conflict theory Explains motion sickness as the result of a mismatch among information from vision, the vestibular system, and kinesthesis.
Shape constancy The perceived shape of an object is unaffected by changes in its retinal image.
Size constancy The perceived size of an object remains constant, despite changes in its retinal image.
Skin senses The senses of touch, pressure, pain, heat, and cold.
Somesthetic senses Sensations produced by the skin, muscles, joints, viscera, and organs of balance.
Stereoscopic vision Perception of space and depth due to the fact that the eyes receive different images.
Taste bud The receptor organ for taste.
Top-down processing Applying higher-level knowledge to rapidly organize sensory information into a meaningful perception.
Transducers Devices that convert one kind of energy into another.
Trichromatic theory Theory of color vision based on three cone types: red, green, and blue.
Vestibular senses The senses of balance, gravity, and acceleration.
Visual acuity The sharpness of visual perception.
Warning system Pain based on large nerve fibers; warns that bodily damage may be occurring.
Video Suggestions
The Brain: Teaching Modules (Visual Information Processing: Elementary Concepts) (Annenberg, 1997, 8 min. 45 seconds)
This video clip depicts the original pioneering research on how the brain's visual systems transmit and encode information. Researchers present their work on the visual cortex of the monkey using x-ray images. Two Nobel laureates also recount their serendipitous discovery of "feature detector" cells in the striate cortex that respond only to stimuli of certain sizes or direction of movement.
The Brain: Teaching Modules (Perception: Inverted Vision) (Annenberg, 1997, 4 min. 54 seconds)
This video examines the peculiar process of image inversion that is part of normally functioning human vision. It follows an art student who wears lenses that invert her visual world.
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The Brain: Teaching Modules (Sensory-Motor Integration) (Annenberg, 1997, 3 min. 11 seconds)
This video clip showsthree spectacular dives of Olympic gold-medalist Greg Louganis to provide vivid illustration of the human body in motion. The complex visual and motor coordination involved in sophisticated sensory-motor integration calls upon the faculties of the motor cortex, cerebellum, and basal ganglia. The roles of kinesthesis, vestibular functions, and cutaneous sensitivity are also covered.
Discovering Psychology: Sensation and Perception (Annenberg, 2001, 30 min.)
This film demonstrates how visual information is gathered and processed and how our culture, previous experiences, and interests influence our perception,
Eye Exam (Films for the Humanities and Sciences, 2008, 19 minutes)
This video addresses common sight defects including myopia, presbyopia, hyperopia, floaters, and many more.
Is Seeing Believing? (Films for the Humanities and Sciences, 2010, 60 minutes)
This film looks at cutting edge research on how the five senses work together, sometimes creating illusions.
Mystery of the Senses (PBS, 2007, 276 min. on five discs)
This series examines the science behind the five major senses.
Perception (Films for the Humanities and Sciences, 1998, 48 minutes)
This film explores major theories of perception (e.g., constructivism, structuralist, gestalt, and so forth) along with the organizational principles from the Gestalt tradition.
The Secret World of Pain (Films for the Humanities and Sciences, 2011, 52 minutes)
This film reveals the psychological foundations of both chronic pain and the lack of pain. Case studies are used to make the film interesting for student viewers.
Sight. (Films for the Humanities and Sciences, 2008, 44 min.)
The king of senses, vision, is explored in this DVD. It examines the importance of human vision and how new technology may help the sightless.
Multimedia Resources
PowerLecture with JoinIn™ and ExamView ® for Introduction to Psychology: Gateways to Mind and Behavior, 13th Edition.
Websites
Companion Site www.cengage.com/psychology/coon
Rods and Cones
http://www.innerbody.com/image/nerv07.html
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Seeing, Hearing, and Smelling the World
http://www.hhmi.org/senses
Ishihara Test for Colorblindness
http://www.toledo-bend.com/colorblind/Ishihara.html
World Health Organization: Deafness
http://www.who.int/topics/deafness/en/
The Perception of Depth
http://webvision.med.utah.edu/KallDepth.html
Visual Illusions
http://www.visualillusion.net/Intro/
Digital Media Library 3.0
“Anatomy of Skin” (Simulation allowing practice in identifying parts of the skin, 1 minute)
“Anatomy of the Eye” (Simulation allowing rotation of the eye to view various structures, NT)
“Artificial Eye” (Video showing how new technology helps the blind with spatial recognition and navigation, 2 minutes, 13 seconds)
“Change Blindness” (Video illustrating change blindness, 6 minutes, 1 second)
“Color Blindness in Visual Periphery” (Simulation illustrating features of peripheral vision, NT
”Common Fate” (Simulation of this Gestalt grouping principle, 1 minute)
“Cone Response Profiles and Hue” (Simulation of relations between cones and response to wavelength, 1 minute)
“Convergence as a Depth Cue” (Simulation of eye movement in response to distance, 2 minutes)
“Dark Adaptation of the Rods and Cones” (Simulation, NT)
“Depth Perception” (Simulation that tests your depth perception, NT)
“Dichromats and Monochromats” (Simulation of how these different types of people view a scene, NT
“Disparity and Retinal Location” (Simulation of this depth cue, NT)
“Figure-Ground Ambiguity” (Simulation of how real-world cues alter our perceptions of visual illusions, 30 seconds)
“Hearing” (Learning module on the steps in the hearing process, 8 minutes)
“Moon Illusion”(Animation of this illusion with respect to size constancy, 4 minutes 3 seconds)
“Motion Parallax” (Video demonstration, 13 seconds)
“Olfactory System” (Simulation allowing practice identifying parts of this system, 2 minutes, 30 seconds)
“Overview of the functioning of the Eye and Retina” (Animation, 28 seconds)
“Ringtones and the Cochlea” (Video of a new ringtone popular with the younger crowd, 3 minutes, 24 seconds)
“Size Constancy” (Brief) (animation, 1 minute)
“Taste System” (Simulation allowing practice in identifying parts of this system, 1 minute, 45 seconds)
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“The Gate Control System” (Simulation of different pathways in this system, 1 minute, 30 seconds)
“The Müller-Lyer Illusion” (Simulation, 2 minutes)
Supplemental Lecture
Have the students read the section in the text on the skin senses, noting that pain is one of these. This lecture should interest students because it deals with a topic of interest to everyone, i.e., control of pain. You should establish what pain is and then discuss how to cope with it. You should be able to generate some lively discussion.
CONTROL OF PAIN
I. The Skin Senses
A. Is there a sense of touch? Discuss the popular notion. Ask students to identify what makes up the so-called sense of touch.
B. Discussion should yield the information that there are really at least three distinct sensations (pressure, temperature, and pain) involved in what has been lumped together as the touch sense.
II. The Pain Sense
A. Is it one sense or many? Discuss the types of pain found in the skin, in the head, teeth, ankle, knee, etc., and in the internal organs.
B. Distinguish between sudden sharp pain, as in a pin prick, and chronic pain, such as a backache or headache.
III. Treatment of Pain
A. Sudden and sharp pain can often be diagnosed and treated because the source can be identified.
B. Chronic pain may be harder to diagnose and treat. Some techniques may be useful to minimize the pain, even when the source of pain is unclear and/or untreatable as is found in arthritis, cancer, and lower back problems.
IV. Techniques for Minimizing Pain
A. Some techniques have been gaining recognition by professionals. The following are some examples. Others could be explored.
1. Preparation
a. Knowing what will happen is a good way to ease pain.
b. Anxiety causes pain to be more intense. Preparation relieves anxiety. A good example is prenatal classes preparing for natural childbirth.
c. Control over painful stimuli lessens anxiety and distress, resulting in less suffering.
2. Reinterpretation
Pain tolerance can be increased by interpreting the circumstances or stimuli in a positive way. The pain of training for an athlete may be reinterpreted as good because it is evidence of progress: “no pain, no gain.” Also the pain suffered for religious reasons by a martyr may be seen as sanctifying and a pleasurable “cross to bear.”
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3. Selective Attention
a. Paying attention to only part of the sensory input and shutting out (tuning out) the rest, including pain, may give relief. A headache may disappear when some emergency situation arises. Injured persons may not feel pain until after the traumatic experience is over.
b. Distractions will help turn attention from pain A dentist may give a patient headphones and soothing music while he is drilling. Fantasizing or daydreaming may relieve the pain of a teacher’s lecture.
c. Hypnosis is a way to direct attention and give relief from pain. For those who can be hypnotized, there could be considerable, or total, pain relief. It has been used in major surgery, dentistry, and childbirth.
4. Sensory Gating
a. One type of pain may cancel another. Discuss this concept in class.
b. Acupuncture is thought to work this way and has been used for centuries in the Far East to kill pain.
c. Electrical stimulation is an interesting modern technique to interfere with pain messages. Gating is said to explain how it works.
d. We often use counter-irritation to relieve pain. Pain in another area may relieve uncontrollable pain. As a result, someone who has a severe localized pain in one area may cause a controlled pain in another area to get relief. The “white knuckle” phenomenon in the dentist’s chair may be an example of this.
5. Drugs
a. Analgesics are pain-killing drugs. Aspirin is one of these. For severe pain, major pain-killing drugs may be needed. Morphine has been used. Discuss the various types and the problems with side-effects including addiction.
b. Placebos are not real drugs but may give relief from pain. These may stimulate production of endorphins, or they may simply have some other psychological effects. Discussion of these may be interesting.
B. A discussion of endorphins as nature’s way of giving relief should be productive. How some of the above techniques might stimulate production of these chemicals should be examined.
C. A class assignment which could be given prior to this lecture, or after, is to have students do some research on these techniques. Give each type to a group of students to study and report to the rest of the class.
Supplemental Lecture
CLOSURE
Closure is one principle of perception that is often treated somewhat superficially. Many seldom go beyond seeing it as joining dots to form a line or a figure. It is interesting to think about ways in which closure may be a factor in our everyday experiences. This lecture should be a discussion with the class about their experiences with this phenomenon. They will be surprised to find that it is an important factor in their perception of the world.
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I. Definition
A. The common definition refers to closure as the tendency to complete a figure. Where gaps are found in a line, people tend to see it as continuous. This is a rather simplistic definition. The phenomenon presents itself in a number of other ways that are significant to the individual.
B. A fuller definition of closure says that we have a natural tendency to perceive stimuli as wholes. This concept is basic to Gestalt psychology. It is the inclination to complete incomplete stimuli, the tendency to fill in the gaps when sensory data are incomplete.
C. Another way to look at it is that we have a natural tendency to give meaning to our experiences. It is possible to extend the concept to explain how people interpret events in their lives, ideas about the world, news reports, etc. It helps us to see why people who have the same experiences interpret them differently.
II. Applications of the Principle
A. As gossip is spread, it grows and changes. Most of the time, gossip comes in fragments of information. The natural tendency to bring closure, to complete the picture, results in some embellishment or addition. When we pass it on, it is tidied up a bit, and some “gaps” are filled in. Each participant in spreading the gossip does the same. The story grows and becomes more interesting with each transmission.
B. Projective tests use closure. They present ambiguous stimuli, and the subject is asked to fill in the gaps. The subject is required to tell what s/he sees in response to incomplete, vague, or inconclusive stimuli.
C. Television makes use of closure. The picture on the screen is made up of a series of dots, and the viewer is required to fill in the spaces to produce the images which flow out of “the tube.” Marshall McLuhan coined the expression, “The medium is the message.” He believed that television shapes the viewer’s perception of the world because the viewer must become involved with producing the images. He pointed out that the stories and pictures about the Viet Nam War, which the American citizens saw on the evening news, made them participants. He saw television as a “hot medium” because it got the viewer involved. This was, and is, the principle of closure at work in our perception of the world through television.
D. Eyewitness accounts of an accident or crime almost always differ. Most viewers see only a part of the whole event, and what they see may pass by quickly. The natural tendency to want to make experiences complete results in a story by the witness which is only partially factual. Usually several witnesses are needed to piece together what really happened.
III. With What Does a Person Fill in the Gaps?
A. This is a good discussion question because students should begin to see that it has to come from within the perceiver. It is from one’s own experience. That is what makes a projective test work. The subject reveals something of himself/herself in the responses. People who hear a siren in the distance may think it is an ambulance, a police car, or a fire truck, depending on their past, and often their most recent, experiences.
B. Discuss why people disagree about the meaning of world events reported in the news media.
C. Ask the students to think about the effects of television violence on viewers, especially on children. What would McLuhan say about this important question?
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IV. An Exercise
A. Ask the students to stand in straight lines of about ten persons each. Prepare ahead of time an ambiguous message about a test or assignment. Write the message on a piece of paper and give it to the first person in each line. Ask that person to read the message silently and return it to you. Then ask this person to whisper the message to the next person. Ask each one to pass the message on. Ask the last person to write the message on a pad.
B. Compare the message given at the beginning and the message received at the end. Discuss how closure is a factor in this process.
Suggestions for Further Reading
Journal Articles:
Bem, D. (2011). Feeling the future: Experimental evidence for anomalous retroactive influences on cognition and affect. Journal of Personality and Social Psychology, 100, 407425.
Boduroglu, A., Shah, P., & Nisbett, R. E. (2009). Cultural differences in allocation of attention in visual information processing. Journal of Cross-Cultural Psychology, 40(3), 349360.
Boksa, P. (2009). On the neurobiology of hallucinations. Journal of Psychiatry & Neuroscience, 34(4), 260-262.
Cammaroto, S., D'Aleo, G., Smorto, C., et al. (2008). Charles Bonnet syndrome. Functional Neurology, 23(3), 123-127.
Danziger, N., Prkachin, K. M., & Willer, J.-C. (2006). Is pain the price of empathy? The perception of others’ pain in patients with congenital insensitivity to pain. Brain: A Journal of Neurology, 129(9), 2494–2507.
Dixon, M. J., Smilek, D., & Merikle, P. M. (2004). Not all synaesthetes are created equal: Projector versus associator synaesthetes. Cognitive, Affective, & Behavioral Neuroscience, 4(3), 335–343.
Hollins, M. (2010). Somesthetic senses. Annual Review of Psychology, 61, 243-271.
Johnson, K. J., & Fredrickson, B. L. (2005). “We all look the same to me”: Positive emotions eliminate the own-race bias in face recognition. Psychological Science, 16(11), 875–881.
Rolls, E. T. (2008). Top-down control of visual perception: Attention in natural vision. Perception, 37(3), 333–354.
Simons, D. J., & Chabris, C. F. (1999). Gorillas in our midst: Sustained inattentional blindness for dynamic events. Perception, 28, 1059–1074.
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Wise, R. A., & Safer, M. A. (2010). A comparison of what U.S. judges and students know and believe about eyewitness testimony. Journal of Applied Social Psychology, 40(6), 14001422.
Textbooks: Foley, H. J., & Matlin, M. W. (2010). Sensation and perception (5th ed.). Boston: Pearson/Allyn and Bacon.
Goldstein, E. B. (2010). Sensation and perception (8th ed.). Belmont, CA: Cengage Learning/Wadsworth.
Popular Press Articles and Books:
Alcock, J. E., Burns, J., & Freeman, A. (2003). Psi wars: Getting to grips with the paranormal. Exeter, UK: Imprint Academic Press.
Barry, S. R., & Sacks, O. (2009). Fixing my gaze. New York: Basic Books.
Marks, D. F. (2000). The psychology of the psychic. Buffalo, NY: Prometheus.
Schick, T., & Vaughn, L. (2001). How to think about weird things: Critical thinking for a new age. New York: McGraw-Hill.
Seckel, A. (2000). The art of optical illusions. London: Carlton Books.
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Handout 4.1
Name _________________________________
CUTANEOUS TWO-POINT THRESHOLD
Some guidelines for doing this exercise:
1. Be sure the subject is securely blindfolded.
2. Apply even, firm, but not excessive pressure with one point or two, as directed. You should avoid causing pain to (or breaking the skin of) the subject.
3. Make exact measurements when setting the two points for each trial.
4. Do not repeat any trials.
5. Ask the subject for a response after each application of pressure.
6. Do not give hints or clues to help the subject. Encourage the subject to make an immediate response.
For each response made by the subject, put a 1 or 2 in the appropriate box.
© 2013 Wadsworth, a division of Cengage Learning.
Handout 4.1 (continued) DATA SHEET
On the chart below, the distance (Dst) between points and the number of points (Pts) to be applied are indicated. Record the responses (Res.) of the subjects in the space provided.
© 2013 Wadsworth, a division of Cengage Learning.
arm
Dst. Pts. Res . Dst. Pts. Res . Dst. Pts. Res . 2” 1 2 2 1 1/2 ” 2 1 2 3/4 ” 2 1 2 1 3/4 ” 2 1 2 1 1/4 ” 1 2 2 5/8 ” 1 2 2 1 1/2 ” 1 1 2 1” 1 2 1 1/2 ” 1 2 1 1 1/4 ” 1 2 1 3/4 ” 2 2 1 3/8 ” 1 1 2 1” 2 1 2 1/2 ” 1 2 1 1/4 ” 2 1 2 3/4 ” 2 2 1 1/4 ” 1 1 2 1/8 ” 2 2 1 1/2 ” 1 2 1 1/8 ” 2 1 2 1/1 6” 1 2 1 1/4 ” 1 2 1 1/1 6” 2 1 2
back of hand finger
© 2013 Wadsworth, a division of Cengage Learning.
Handout 4.2
Name _________________________________
THE STROOP EFFECT: COLOR WORD LIST
YELLOW YELLOW BLUE YELLOW
GREEN RED YELLOW GREEN
GREEN BLUE RED YELLOW
RED GREEN BLUE RED
GREEN BLUE GREEN BLUE
BLUE RED RED YELLOW
THE STROOP EFFECT: DATA SHEET
©
2013 Wadsworth, a division of Cengage Learning.
SUBJECT TIME (in seconds) LIST #1 LIST #2 LIST #3 1 2 3 4 5 6 7 8 9 10
Handout 4.3
Name _________________________________
MENTAL TELEPATHY; OR, IT’S IN THE CARDS DATA SHEET
© 2013 Wadsworth, a division of Cengage Learning.
TRIALS 1 2 3 4 5 1 2 3 4 5 6 7 8 9 10 11 12 13 TRIALS 1 2 3 4 5 1 2 3 4 5 6 7 8 9 10 11 12 13
©
2013 Wadsworth, a division of Cengage Learning.
