Perceptual Interpretation

Transcription

1 LI.I...I ::l C o Perceptual Interpretation :E MODULE OVERVIEW Sensory Deprivation and Restored Vision (pp ) Module 17 explores how we interpret our sensations into meaningful perceptions. It deals with two important issues. The first issue is the role of experience, as opposed to heredity, in perception. Make sure you understand the results of studies of recovery from blindness, early sensory restriction, adaptation to distorted environments, and perceptual set. The second is the possible existence of ESP, or perception without sensation. You should be able to discuss both the claims made for ESP and the criticisms of these claims. Human factors psychologists study the interaction of people and machines and try to find ways to increase safety and productivity. NOTE: Answer guidelines for all Module 17 questions begin on page 201. MODULE REVIEW First, skim each section, noting headings and boldface items. After you have read the section, review each objective by answering the fill-in and essay-type questions that follow it. As you proceed, evaluate your performance by consulting the answers on page 201. Do not continue with the next section until you understand each answer. If you need to, review or reread the section in the textbook before continuing. David Myers at times uses idioms that are unfamiliar to some readers. If you do not know the meaning of the following words in the context in which they appear in the text, refer to page 203 for an explanation: Ping-Pong ball. Objective 17-1:Describe the contribution of restoredvision and sensory deprivation research in our understanding of the nature-nurture interplay in our perceptions. 1. The idea that knowledge comes from inborn ways of organizing sensory experiences was proposed by the philosopher 2. On the other side were philosophers who maintained that we learn to perceive the world by experiencing it. One philosopher of this school was 3. Studies of cases in which vision has been restored to a person who was blind from birth show that, upon seeing tactilely familiar objects for the first time, the person (can/cannot) recognize them. 4. Studies of sensory deprivation demonstrate that visual experiences during are crucial for perceptual development. Such experiences suggest that there is a for normal sensory and perceptual development. For this reason, human infants born with an opaque lens, called a, typically have corrective surgery right away. 197

2 r 198 Module 17 Perceptual Interpretation Objective 17-4: Explain why the same stimulus can evoke different perceptions in different contexts. Perceptual Adaptation (pp ) If you do not know the meaning of any of the following words in the context in which they appear in the text, refer to page 203 for an explanation: we may feel slightly disoriented, even dizzy. Objective 17-2: Explain how the research on distorting goggles increases our understanding of the adaptability of perception. 4. How a stimulus is perceived depends on our perceptual schemas and the in which it is experienced. 5. The context of a stimulus creates a (top-down/bottom-up) expectation that influences our perception as we match our (top-down/bottom-up) signal against it. 6. Our perception is also influenced by 1. Humans given glasses that shift or invert the visual field. (will/will not) adapt to the distorted perception. This is called about gender and the context of our experiences. Perception and Human Factor (pp ) 2. Animals such as chicks (adapt/ do not adapt) to distorting lenses. 3. When distorting goggles are first removed, most people experience a brief perceptual, as their perceptual systems continue to compensate for the shifted visual input. Perceptual Set (pp ) Objective 17-5: Describe the role human factors psychologists play in creating user-friendly machines and work settings. 1. Psychologists who study the importance of con- sidering perceptual principles in the design of machines, appliances, and work settings are called psychologists. 2. Victims of the "curse of knowledge," technology If you do not know the meaning of any of the following words, phrases, or expressions in the context in which they appear in the text, refer to page 203 for an explanation: to see is to believe... to believe is to see; a "monster" in Scotland's Loch Ness;from what's behind our eyes and between our ears; in the eyes of their beholders. Objective 17-3: Define perceptual set, and explain how it influences what we do or do not perceive. developers who assume that others share their, may create designs that are unclear to others. 3. Another example of failure to consider the human factor in design is the technology that provides embarrassing headsets that amplify sound for people with hearing loss. Is There Extrasensory Perception? (pp ) 1. A mental predisposition that influences percep- tion is called a 2. Through experience, people acquire perceptual, as reflected in children's drawings at different ages. This explains why we more accurately recognize of famous faces than these people's actual faces. 3. Our face recognition is especially attuned to the expressive areas of the and If you do not know the meaning of any of the following words, phrases, or expressions in the context in which they appear in the text, refer to pages for an explanation: uncanny; mind-blowing performance; unsatisfied hunger... an itch.

3 Progress Test Objective 17-6:Identify the three most testable forms of ESP, and explain why most research psychologists remain skeptical of ESP claims. 1. Perception outside the range of normal sensation is called 2. Psychologists who study ESP are called 3. The form of ESP in which people claim to be capable of reading others' minds is called. A person who "senses" that a friend is in danger might claim to have the ESP ability of. An ability to "see" into the future is called. A person who claims to be able to levitate and move objects is claiming the powerof 4. Analyses of psychic visions and premonitions reveal (high/ chance-level) accuracy. Nevertheless, some people continue to believe in their accuracy because vague predictions often are later to match events that have already occurred. In addition, people are more likely to recall or dreams that seem to have come true. 5. Critics point out that a major difficulty for parapsychology is that ESP phenomena are not consistently 6. Researchers who tried to reduce external distractions between a "sender" and a "receiver" in an ESP experiment reported performance levels that (beat/ did not beat) chance levels. More recent studies (failed to replicate the results/found equally high levels of performance). PROGRESS TEST Multiple-Choice Questions Circle your answers to the following questions and check them with the answers beginning on page 201. If your answer is incorrect, read the explanation for why it is incorrect and then consult the appropriate pages of the text A person claiming to be able to read another's mind is claiming to have the ESP ability of: a. psychokinesis. c. clairvoyance. b. precognition. d. telepathy. 2. Which philosopher maintained that knowledge comes from inborn ways of organizing our sensoryexperiences? c. Stratton a. Locke d. Norman b. Kant 3. Dr. Martin is using natural mapping to redesign the instrument gauges of automobiles to be more "user friendly." Dr. Martin is evidently a(n): a. psychophysicist. b. cognitive psychologist. c. human factors psychologist. d. experimental psychologist. 4. Kittens and monkeys reared seeing only diffuse, unpatterned light: a. later had difficulty distinguishing color and brightness. b. later had difficulty perceiving color and brightness, but eventually regained normal sensitivity. c. later had difficulty perceiving the shape of objects. d. showed no impairment in perception, indicating that neural feature detectors develop even in the absence of normal sensory experiences. 5. Adults who are born blind but later have their vision restored: a. are almost immediately able to recognize familiar objects. b. typically fail to recognize familiar objects. c. are unable to follow moving objects with their eyes. d. have excellent eye-hand coordination. 6. Which of the following influences perception? a. biological maturation b. the context in which stimuli are perceived c. expectations d. all of the above 7. Jack claims that he often has dreams that predict future events. He claims to have the power of: a. telepathy. c. precognition. b. clairvoyance. d. psychokinesis.

4 200 Module 17 Perceptual Interpretation 8. Researchers who investigated telepathy found that: a. when external distractions are reduced, both the "sender" and the "receiver" become much more accurate in demonstrating ESP. b. only "senders" become much more accurate. c. only "receivers" become much more accurate. d. over many studies, none of the above occur. 9. Experiments with distorted visual environments demonstrate that: a. adaptation rarely takes place. b. animals adapt readily, but humans do not. c. humans adapt readily, while lower animals typically do not. d. adaptation is possible during a critical period in infancy but not thereafter. 10. The phenomenon that refers to the ways in which an individual's expectations influence perception is called: a. perceptual set. b. perceptual adaptation. c. clairvoyance. d. telekinesis. 11. Thanks to, TiVo and DVR have solved the TV recording problem caused by the complexity of VCRs. a. parapsychologists b. human factors psychologists c. psychokineticists d. Gestalt psychologists 12. According to the philosopher to perceive the world. a. Locke c. Stratton b. Kant d. Norman, we learn 13. Which of the following statements best describes the effects of sensory restriction? a. It produces functional blindness when experienced for any length of time at any age. b. It has greater effects on humans than on animals. c. It has more damaging effects when experienced during infancy. d. It has greater effects on adults than on children. 14. Psychologists who study ESP are called: a. clairvoyants. c. parapsychologists. b. telepaths. d. levitators. 15. Which of the following statements concerning ESP is true? a. Most ESP researchers are quacks. b. There have been a large number of reliable demonstrations of ESP. c. Most research psychologists are skeptical of the claims of defenders of ESP. d. There have been reliable laboratory demonstrations of ESP, but the results are no different from those that would occur by chance. 16. Although carpenter Smith perceived a briefly viewed object as a screwdriver, police officer Wesson perceived the same object as a knife. This illustrates that perception is guided by: a. psychokinetics. b. perceptual adaptation. c. critical periods. d. perceptual set. 17. Regina claims that she can bend spoons, levitate furniture, and perform many other "mind over matter" feats. Regina apparently believes she has the power of: a. telepathy. c. precognition. b. clairvoyance. d. psychokinesis. 18. The predictions of leading psychics are: a. often ambiguous prophecies later interpreted to match actual events. b. no more accurate than guesses made by others. c. nearly always inaccurate. d. all of the above. True-False Items Indicate whether each statement is true or false by placing Tor F in the blank next to the item. 1. Laboratory experiments have laid to rest all criticisms of ESP. 2. Unlike other animals, humans have no critical period for visual stimulation. 3. Immanuel Kant argued that experience determined how we perceive the world. 4. After a period of time, humans are able to adjust to living in a world made upside down by distorting goggles. S. Perception is influenced by psychological factors such as set and expectation as well as by physiological events. 6. John Locke argued that perception is inborn.

5 Answers 201 KEY TERMS Using your own words, on a separate piece of paper write a brief definition or explanation of each of the following terms. 1. perceptual adaptation 2. perceptual set 3. human factors psychology 4. extrasensory perception (ESP) S. parapsychology ANSWERS Module Review Sensory Deprivation 1. Kant 2. Locke 3. cannot and Restored Vision 4. infancy; critical period; cataract Perceptual Adaptation 1. will; perceptual adaptation 2. do not adapt 3. aftereffect Perceptual Set 1. perceptual set 2. schemas; caricatures 3. eyes; mouth 4. context S. top-down; bottom-up 6. stereotypes; emotional Perception and the Human Factor 1. human factors 2. expertise 3. assistive listening Is There Extrasensory 1. extrasensory perception 2. parapsychologists Perception? 3. telepathy; clairvoyance; precognition; psychokinesis 4. chance-level; interpreted (retrofitted); reconstruct S. reproducible 6. beat; failed to replicate the results Progress Test Multiple-Choice Questions 1. d. is the answer. a. Psychokinesis refers to the claimed ability to perform acts of "mind over matter." b. Precognition refers to the claimed ability to perceive future events. c. Clairvoyance refers to the claimed ability to perceive remote events. 2. b. is the answer. a. Locke argued that knowledge is not inborn but comes through learning. c. Stratton experimented with distorting goggles. d. Norman hosts a Web site on designing equipment for people. 3. c. is the answer. 4. c. is the answer. a. & b. The kittens had difficulty only with lines they had never experienced, and never regained normal sensitivity. d. Both perceptual and feature-detector impairment resulted from visual deprivation. S. b. is the answer. Because they have not had early visual experiences, these adults typically have difficulty learning to perceive objects. a. Such patients typically could not visually recognize objects with which they were familiar by touch, and in some cases this inability persisted. c. Being able to perceive figure-ground relationships, patients are able to follow moving objects with their eyes. d. This answer is incorrect because eye-hand coordination is an acquired skill and requires much practice. 6. d. is the answer. 7. c. is the answer. a. This answer would be correct had Jack claimed to be able to read someone else's mind. b. This answer would be correct had Jack claimed to be able to sense remote events, such as a friend in distress.

6 202 Module 17 Perceptual Interpretation d. This answer would be correct had Jack claimed to be able to levitate objects or bend spoons without applying any physical force. 8. d. is the answer. 9. c. is the answer. Humans and certain animals, such as monkeys, are able to adjust to upsidedown worlds and other visual distortions, figuring out the relationship between the perceived and the actual reality; lower animals, such as chickens and fish, are typically unable to adapt. a. Humans and certain animals are able to adapt quite well to distorted visual environments (and then to readapt). b. This answer is incorrect because humans are the most adaptable of creatures. d. Humans are able to adapt at any age to distorted visual environments. 10. a. is the answer. b. Retinal disparity is a binocular depth cue based on the fact that each eye receives a slightly different view of the world. c. Convergence is a binocular depth cue based on the fact that the eyes swing inward to focus on near objects. d. Visual capture refers to the tendency of vision to dominate the other senses. 11. b. is the answer. a. Parapsychologists study claims of ESP. c. Psychokineticists are people who claim ESP has the power of "mind over matter." d. Gestalt psychologists emphasize the organization of sensations into meaningful perceptions. 12. a. is the answer. b. Kant claimed that knowledge is inborn. c. Stratton experimented with distorting goggles. d. Norman hosts a Web site on designing equipment for people. 13. c. is the answer. There appears to be a critical period for perceptual development, in that sensory restriction has severe, even permanently, disruptive effects when it occurs in infancy but not when it occurs later in life. a. & d. Sensory restriction does not have the same effects at all ages, and it is more damaging to children than to adults. This is because there is a critical period for perceptual development; whether functional blindness will result depends in part on the nature of the sensory restriction. b. Research studies have not indicated that sensory restriction is more damaging to humans than to animals. 14. c. is the answer. a., b., & d. These psychics claim to exhibit the phenomena studied by parapsychologists. 15. c. is the answer. a. Many ESP researchers are sincere, reputable researchers. b. & d. There have been no reliable demonstrations of ESP. 16. d. is the answer. The two people interpreted a briefly perceived object in terms of their perceptual sets, or mental predispositions, in this case conditioned by their work experiences. a. Both Smith and Wesson had the same sensory experience of the object, so linear perspective cues would not cause their differing perceptions. b. Shape constancy refers to the perception that objects remain constant in shape even when our retinal images of them change. c. Retinal disparity is a binocular depth cue; it has nothing to do with individual differences in perception. 17. d. is the answer. a. Telepathy is the claimed ability to "read" minds. b. Clairvoyance refers to the claimed ability to perceive remote events. c. Precognition refers to the claimed ability to perceive future events. 18. d. is the answer. True-False Items 1. F 2. F 3. F 4. T S. T 6. F Key Terms 1. Perceptual adaptation refers to our ability to adjust to an artificially displaced or even inverted visual field. Given distorting lenses, we perceive things accordingly but soon adjust by learning the relationship between our distorted perceptions and the reality. 2. Perceptual set is a mental predisposition to perceive one thing and not another. 3. Human factors psychology explores how people and machines interact and how machines and physical environments can be adapted to human behaviors and thus to increase safety and productivity.

7 Focus on Vocabulary and Language 4. Extrasensory perception (ESP) refers to the controversial claim that perception can occur without sensory input. Supposed ESP powers include telepathy, clairvoyance, and precognition. Memory aid: Extra- means "beyond" or "in addition to"; extrasensory perception is perception outside or beyond the normal senses. FOCUS ON VOCABULARY AND LANGUAGE Sensory Deprivation and Restored Vision Most had been born with cataracts- clouded lenses that allowed them to see only diffused light, rather as you or I might see a diffuse fog through a PingPong ball sliced in half. People born with cataracts cannot see clearly because the normally transparent lenses in their eyes are opaque. To understand what their vision is like, imagine what you would see if you had your eyes covered with half of a small, white, plastic ball that is used in table tennis (PingPong). When cataract patients have their vision restored, after being blind since birth, they can sense colors and distinguish figure from ground (innate capacities), but they cannot visually recognize things that were familiar by touch. Perceptual Adaptation Given a new pair of glasses, we may feel slightly disoriented, even dizzy. When we start wearing ordinary eyeglasses or when we are fitted with a new pair, our initial reaction is a little confusion and vertigo (dizziness). However, we quickly adapt within a few days. We can also adapt to lenses that distort what we are looking at by 40 to one side, and even to distortion lenses that invert reality (turn the visual image upside down-a topsy-turvy world). Fish, frogs, salamanders, and young chickens cannot adapt in this way. Perceptual Set As everyone knows, to see is to believe. As we also know, but less fully appreciate, to believe is to see. The expression "seeing is believing" means that we put much reliance on visual information when deciding (believing) what is true. Myers shows us that, on the contrary, what we believe may actually affect what we see. Our assumptions, expectations, and mental 203 S. Parapsychology is the study of ESP, psychokinesis, and other paranormal forms of interaction between the individual and the environment. Memory aid: Para-, like extra-, indicates "beyond"; thus, paranormal is beyond the normal and parapsychology is the study of phenomena beyond the realm of psychology and known natural laws. predispositions (perceptual sets) determine, to a large extent, our perceptions. In 1972, a British newspaper published genuine, unretouched photographs of a "monster" in Scotland's Loch Ness... People who had heard about, or believed in, the Loch Ness Monster before seeing a very ambiguous picture of a log were more inclined to see what they expected to see (i.e., a monster) because of their perceptual set. Clearly, much of what we perceive comes not just from the world "out there" but also from what's behind our eyes and between our ears. Myers is reiterating the point that our mental predispositions, expectations, beliefs, etc. (what's behind our eyes and between our ears) influence much more of what we perceive than the sensory stimulation received from the outside world. Some differences, it seems, exist merely in the eyes of their beholders. The familiar saying "beauty is in the eye of the beholder" means that what is perceived as beautiful has more to do with what the perceiver subjectively believes than with the absolute qualities of the person or object being judged. Likewise, our stereotypes (rigid, conventional ideas or beliefs) about gender or culture can greatly influence (color) what is perceived. Is There Extrasensory Perception?... uncanny... People who have dreams that coincide, by pure chance, with later events often have an eerie or strange (uncanny) feeling about the accuracy of their apparent precognitions.... mind-blowing performances. Some alleged (socalled) psychics, using magic tricks and not extrasensory ability, unethically manipulate and deceive (exploit) gullible (unquestioning) audiences with impressive and wondrous demonstrations (mindblowing performances). As Myers points out, after

8 204 Module 17 Perceptual Interpretation many, many years of investigation and thousands of experiments there is no scientific evidence that extrasensory abilities exist (believers in the paranormal need only produce one person who can demonstrate a single, reproducible ESP phenomenon to refute the claim that there is no ESP-this has not happened). But some people also have an unsatisfied hunger for wonderment, an itch to experience the magical. Some people are predisposed to believe in ESP because they have a deeply felt need (unsatisfied hunger) for surprise and amazement and a strong ambition or desire (an itch) to explore the mysterious and unknown.