Chapter 08 Perceiving Motion PDF

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Chapter 08: Perceiving Motion Multiple Choice 1. The patient L.M. (studied by Zihl, et al.) had cortical lesions that affected her motion perception. What was her condition called? a. prosopagnosi a b. akinetopsia c. stroboscopia d. amblyopia ANSWER: b 2. The patient L.M. (studied by Zihl, et al.), who had cortical lesions that affected her motion perception, experienced a. no problems pouring a cup of coffee b. no difficulty crossing a street c. difficulty following dialogue d. only minor social inconveniences ANSWER: c 3. A mouse “freezes” when it sees a cat nearby. This assists the mouse’s survival because being motionless reduces _____. a. the attention-attracting effect of motion b. the effectiveness of camouflage c. the levels of stress hormones d. the pheromones the mouse gives off ANSWER: a 4. Camouflage can be interpreted as a problem of _____. a. figure-ground segregation b. binocular disparity c. induced movement d. the waterfall illusion ANSWER: a 5. Movies are to _____ as the waterfall illusion is to _____. a. apparent movement; induced movement b. real movement; apparent movement c. movement aftereffects; stroboscopic movement d. apparent movement; movement aftereffects ANSWER: d 6. Our ability to perceive movement when reading “message boards” that are used in advertising is based on _____. a. apparent movement b. movement aftereffects Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion c. waterfall effects d. motion agnosia ANSWER: a 7. Brian looks at the moon and some clouds at night. He perceives the moon moving through the clouds. This is an example of _____. a. induced motion b. the stroboscopic effect c. the Reichardt effect d. the Shedlock effect ANSWER: a 8. Larsen et al. (2006) used fMRI to study the responses of the brain to real and apparent motion and found that _____. a. the pathways overlapped but processing occurred in different brain regions b. both the pathways and the processing areas were distinct c. similar regions of the brain were activated for both d. there was a great deal of idiosyncrasy in the areas involved ANSWER: c 9. As Dore runs through the park, the flow signals that he is moving and not the environment. Gibson calls this _____. a. local disturbances in the optic array b. deletion in the optic array c. the global optic flow d. the bioptic flow ANSWER: c 10. Tom is watching Terri walk across the room. According to Gibson, Tom perceives Terri _____. a. to be moving because her image is moving across his retina b. to be stationary because the background is stationary c. to be moving because of a local disturbance in the optic array d. to be stationary because the background texture is fixed ANSWER: c 11. In addition to describing movement detection in terms of the environment, researchers have proposed different ways to detect movement from a physiological perspective. The Reichardt detector is one solution. Which of the following is the greatest weakness of the Reichardt detector? a. It only explains motion detection for images that cross the receptors. b. It only explains how eye movements can be accounted for in motion detection. c. It only is able to detect lateral movement of stimuli. d. It operates using excitatory and inhibitory signals. ANSWER: a Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion 12. According to corollary discharge theory, movement is perceived when _____. a. there is a disturbance in the global optic array b. the comparator receives the corollary discharge signal and image displacement signal simultaneously c. the comparator receives the corollary discharge signal alone or image displacement signal alone d. the comparator finds dissimilarities between the local and global optic arrays ANSWER: c 13. Which type of signal is sent from the brain to the eye muscles? a. image displacement signal b. ciliary signal c. motor signal d. comparator signal ANSWER: c 14. The _____ signal is sent to other areas of the brain relaying the message that a signal has been sent from the motor cortex to the eye muscles. It is analogous to using the “cc” (copy) function in an email. a. image displacement b. ciliary c. motor d. corollary discharge ANSWER: d 15. Which of the following is true about the corollary discharge theory? a. It can explain why you see a bird moving in flight when you are following it with your eyes. b. It has much behavioral support, but no physiological support yet. c. It has little behavioral support, but the comparator has been found in the IT cortex. d. It can explain why an afterimage seems to be stationary as you move your eye to different fixation points. ANSWER: a 16. An afterimage when viewed in the dark appears to move when you move your eyes. The corollary discharge theory predicts this because _____. a. there is an IDS, but not a CDS b. there is no IDS, but there is a CDS c. there is no IDS and no CDS d. there is both IDS and CDS ANSWER: b 17. Percy is injected with a drug that paralyzes his eye muscles. When he is instructed to try to move his eye when looking Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion a stationary scene, his brain is able to send a signal to his eye muscles but he is unable to move his eyes. As a result, he perceives _____. a. no movement, because his eye muscles can’t move b. no movement, because the scene is stationary c. movement, because there is a CDS and an IDS d. movement, because there is a CDS, but not an IDS ANSWER: d 18. Mira gently pushes on her eye with her finger. Because her eye muscles push against the force of her finger, which keeps the image in the same location, she perceives the visual scene _____. a. to be jiggling b. to be stationary c. to have exaggerated depth d. to be shrinking ANSWER: a 19. R.W., the man who experienced vertigo when he moved his eyes, suffered cortical damage that eliminated _____. a. corollary discharge signals b. image movement signals c. cortical magnification d. binocular cell firing ANSWER: a 20. The vertigo case of R.W. not only provided evidence for the corollary discharge theory, it revealed the importance of the _____ in producing CDS. a. MT area b. PPA c. STS d. MST area ANSWER: d 21. Real-motion neurons found in the monkey cortex fire when _____ moves, but do not fire when _____ moves. a. the eye; a stimulus b. a stimulus; the background c. a stimulus; the eye d. the background; a stimulus ANSWER: c 22. In monkeys, real-motion neurons have been located in _____. a. the extrastriate cortex Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion b. the striate cortex c. the retina d. the brain stem ANSWER: a 23. Newsome, Britten, and Movshon found that as the coherence between the dots’ direction of movement increased, _____. a. the MT neuron fired more rapidly b. the monkey judged the direction of movement less accurately c. the MT neuron fired less rapidly d. the MT neuron fired at rates less than the level of spontaneous activity ANSWER: a 24. A monkey with an intact MT cortex can detect the direction of moving dots when coherence is ____%, while a monkey that has had the MT cortex lesioned detects the direction of the moving dots when coherence is _____%. a. 1-2; 10-20 b. 10-20; 1-2 c. 1-2; 1-2 d. 1-20; 1-2 ANSWER: a 25. The connection between MT neurons and movement perception has been supported by _____. a. lesioning studies only b. microstimulation studies only c. both lesioning and microstimulation studies d. intact brain studies only ANSWER: c 26. The _____ is demonstrated when you look through a circle you make with your fingers, and move a pencil either horizontally or diagonally behind your fingers. a. kinetic depth effect b. structure-from-motion phenomenon c. correspondence problem d. aperture problem ANSWER: d 27. In the pooling solution to the aperture problem, MT neurons receive signals from a number of neurons in the _____ and then combine these signals to determine the actual direction of motion. a. striate cortex b. prefrontal cortex c. cerebellum Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion d. central sulcus ANSWER: a 28. Pack and Born (2001) found that the combining of responses from V1 cells occurs after about ______ after presentation of the moving bars. a. 1 msec b. 20 msec c. 140 msec d. 900 msec ANSWER: c 29. In an apparent motion demonstration, two pictures are used. In one picture, a fist is located behind a board; in the other, the fist is located in front of the board at the same height. When rapidly alternating between these pictures, what apparent motion would result? a. The fist would appear to go around the side of the board. b. The fist would appear to “magically” pass through the board. c. The fist would appear to smash the board. d. No apparent motion would occur; it would look like two still pictures. ANSWER: b 30. In an apparent motion demonstration, two pictures are used. In one picture, a person’s fist is located behind his head; in the other, the person’s fist is located in front of their face at the same height. When slowly alternating between these pictures (less the five times a second), what apparent motion would result? a. The fist would appear to go around the side of the head. b. The fist would appear to “magically” pass through the head. c. The fist would appear to smash the head. d. No apparent motion would occur because the alternation is too slow. ANSWER: a 31. A “point-light walker” wears lights on different body locations. When viewed in a dark room, an observer would perceive a(n) _____. a. person when the point-light walker is not moving b. person when the point-light walker is moving c. person if just one light on the person is moving d. unidentifiable biological organism when the point-light walker is moving ANSWER: b 32. The perceptual grouping of lights in biological motion has been shown physiologically to occur in the _____ area of the cortex. a. superior temporal sulcus b. lateral geniculate Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion c. premotor d. anterior intraparietal ANSWER: a 33. _____ is a technique that has been used to temporarily disturb brain area functioning in humans. a. Lesioning b. Ablation c. Transcranial magnetic stimulation d. Orbital magnetic gyration ANSWER: c 34. Presenting transcranial magnetic stimulation to the area of the STS in humans _____. a. increased the person’s ability to perceive biological motion b. decreased the person’s ability to perceive biological motion c. did not affect the person’s ability to perceive biological motion d. resulted in gender difference in perceiving biological motion ANSWER: b 35. Freyd (1983) presented two pictures sequentially that implied motion, such as a person jumping off a low wall. In the “same” condition, the second picture was identical to the first; in the “time-forward” condition, the second picture was the jumper closer to the ground; and in the “time-backward condition, the jumper was further from the ground. The observer’s task was to respond whether or not the two pictures were the “same” or “different.” The response time was longest for _____. a. the “same” condition b. the “time-forward” condition c. the “time-backward” condition d. both the “same” and “time-backward” conditions ANSWER: b 36. Which of the following stimuli is most likely to show the greatest representational momentum? a. a house b. a rocket c. a coffee mug d. a banana ANSWER: b 37. Kourtzi and Kanwisher (2000) used fMRIs to show that “implied motion” stimuli cause _____. a. greater responses in the MT and MST than “no-implied motion” stimuli b. less firing in the MT and MST than “no-implied motion” stimuli c. less firing in the amygdala than the “house” pictures d. the same amount of firing in the MST as “house” pictures ANSWER: a Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion 38. The real world contains instances of continuous motion that somehow are divided up into meaningful units. The point in time when one unit ends and another begins is referred to as the _____. a. breaking point b. segment marker c. event boundary d. transition period ANSWER: c 39. In one study, Zacks et al. (2009) recorded someone making a sandwich and asked participants to press a button when they thought one action was complete. The results of the study indicated that _____ were indicative of the end of an action. a. pauses b. changes in speed c. changes in hand orientation d. head movements ANSWER: b 40. When L.M. tried to pour a cup of tea, she _____. a. had some trouble aiming, but was able to get most of it in the cup b. perceived the tea as frozen, like a glacier c. could do it accurately if she talked herself through the steps d. typically under-filled the cup because she could not judge the level ANSWER: b Essay 41. Describe the case of the woman with akinetopsia. What does this case tell us about the importance of motion perception? ANSWER Perhaps the most dramatic way to illustrate the importance of motion perception to : daily life (and survival) comes from case studies of individuals who, through disease or trauma, suffer from damage to parts of the brain responsible for perceiving and understanding movement. When this happens, a person is said to suffer from a condition called akinetopsia or “motion blindness,” where motion is either very difficult or impossible to perceive. The most famous and well-studied case of akinetopsia is that of a 43-year-old woman known as L.M. (Zihl et al., 1983, 1991). Without the ability to perceive motion following a stroke, L.M. was unable to successfully complete activities as simple as pouring a cup of tea. As she put it, “the fluid appeared to be frozen, like a glacier,” and without the ability to perceive the tea rising in the cup, she had trouble knowing when to stop pouring. Her condition caused other, more serious problems as well. It was difficult for her to follow dialogue because she couldn’t see the motions of a speaker’s face and mouth, and people suddenly appeared or disappeared because she couldn’t see them approaching or leaving. Crossing the street presented serious problems because at first a car might seem far away, but then suddenly, without warning, it would appear very near. Thus, her disability was not just a social inconvenience but enough of a threat to the woman’s Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion well-being that she rarely ventured outside into the world of moving – and sometimes dangerous – objects. 42. Discuss three types of illusory motion and provide an example of each. ANSWER The most famous, and best studied, type of illusory motion is called apparent motion. : When two stimuli in slightly different locations are alternated with the correct timing, an observer perceives one stimulus moving back and forth smoothly between the two locations. This perception is called apparent motion because there is no actual (or real) motion between the stimuli. This is the basis for the motion we perceive in movies, on television, and in moving signs that are used for advertising and entertainment. Induced motion occurs when motion of one object (usually a large one) causes a nearby stationary object (usually smaller) to appear to move. For example, the moon usually appears stationary in the sky. However, if clouds are moving past the moon on a windy night, the moon may appear to be racing through the clouds. In this case, movement of the larger object (clouds covering a large area) makes the smaller, but actually stationary, moon appear to be moving. Motion aftereffects occur when viewing a moving stimulus causes a stationary stimulus to appear to move (Glasser et al., 2011). One example of a motion aftereffect is the waterfall illusion (Addams, 1834). If you look at a waterfall for 30 to 60 seconds (be sure it fills up only part of your field of view) and then look off to the side at part of the scene that is stationary, you will see everything you are looking at - rocks, trees, grass appears to move upward for a few seconds. If you’re short on waterfalls, next time you are at the cinema, you may be able to induce this illusion by carefully watching the rolling credits at the end of the movie (you should sit toward the rear of the theater). 43. (a) What does Gibson mean by the “optic array”? (b) Specify how changes in the optic array affect movement perception. ANSWER Gibson’s approach (1950, 1966, 1979) involves looking for information in the : environment that is useful for perception. This information for perception, according to Gibson, is located not on the retina but “out there” in the environment. He thought about information in the environment in terms of the optic array – the structure created by the surfaces, textures, and contours of the environment – and he focused on how movement of the observer causes changes in the optic array. Local disturbance in the optic array occurs when there is movement relative to the environment, covering and uncovering the stationary background. According to Gibson, this local disturbance in the optic array provides information that movement is occurring relative to the environment. 44. What is the aperture problem? How does the visual system “solve” this problem? ANSWER The fact that viewing only a small portion of a larger stimulus can result in misleading : information about the direction in which the stimulus is moving is called the aperture problem. There are at least two solutions to the aperture problem. 1. A neuron could use information about the end of a moving object (such as the tip of the pencil) to determine its direction of motion. As it turns out, neurons that could Copyright Cengage Learning. Powered by Cognero.

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Chapter 08: Perceiving Motion signal this information, because they respond to the ends of moving objects, have been found in the striate cortex. 2. The second solution is to pool, or combine, responses from a number of neurons. Apparently, MT neurons receive signals from a number of neurons in the striate cortex and then combine these signals to determine the actual direction of motion. 45. (a) Describe the major components and principle of the corollary discharge theory. (b) Describe two behavioral demonstrations that support the corollary discharge theory and specify how the theory predicts the result. ANSWER The three components of corollary discharge theory are: : 1. An image displacement signal (IDS) occurs when an image moves across receptors in the retina. 2. A motor signal (MS) occurs when a signal is sent from the brain to the eye muscles. 3. A corollary discharge signal (CDS) is a copy of the motor signal that, instead of going to the eye muscles, is sent to a different place in the brain. This is analogous to using the “cc” (copy) function when sending an email message. The email goes to the person it is addressed to, and a copy of the email is simultaneously sent to someone else at another address. Why does an afterimage appear to move when you move your eyes? The answer cannot be that an image is moving across your retina because the circle’s image always remains at the same place on the retina. (The circle’s image on the retina has created a small area of bleached visual pigment, which remains in the same place no matter where the eye is looking.) Without motion of the stimulus across the retina, there is no image displacement signal. However, the motor signals sent to ...