Chapter 3 Neural Processing PDF

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Chapter 03: Neural Processing Multiple Choice 1. Hartline et al. (1956) selected the Limulus to demonstrate lateral inhibition because _____. a. it was possible to illuminate a single receptor without illuminating its adjacent receptor b. it was readily available to him and was extremely easy to breed in the lab c. the Limulus eye contained more cones than rods d. the Limulus has excellent color vision ANSWER: a 2. A receptor array in the Limulus is connected by the lateral plexus. Receptor “A” is located 5 receptors to the left of Receptor “B.” What stimulation will result in the greatest firing rate recorded from “A”? a. stimulate A with 10 units of illumination b. stimulate A with 10 units of illumination and stimulate B with 10 units c. stimulate A with 10 units of illumination and stimulate B with 20 units d. stimulate A with 5 units of illumination and stimulate B with 20 units ANSWER: a 3. _________: Limulus :: ________: human retina. a. Horizontal cells; amacrine cells b. Amacrine cells; horizontal cells c. Lateral plexus; horizontal and amacrine cells d. Lateral plexus; rods ANSWER: c 4. Human lateral inhibition is most likely accomplished by _____. a. end-stopped cells b. extrastriate cells c. bipolar cells d. dissociative cells ANSWER: c 5. Lateral inhibition has previously been used to explain _____. a. the Hermann Grid only b. Mach bands and the Hermann Grid, but not the Chevreul illusion c. Chevreul illusion only d. the Hermann Grid and Mach bands, and the Chevreul illusion ANSWER: d 6. The gray intersections in the Hermann Grid _____. a. are physically present b. are explained by dark adaptation c. support the claim that “perception is not the same as the physical stimulus” Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing d. support the claim that what is learned in animals is not applicable to humans ANSWER: c 7. In Hermann’s grid, a possible explanation for why gray areas appear at the intersections is because _____. a. the amount of inhibition right at the intersections is twice as great as the inhibition between each square b. the amount of inhibition right at the intersections is much less than the inhibition between each square c. the superior colliculus responds maximally as you move your eye from intersection to intersection d. moving the eye creates a blur at all the intersections ANSWER: a 8. In Mach bands, the darker area sends _____ lateral inhibition to the lighter area than the lighter area sends to the darker area. a. less b. more c. the same amount of d. no ANSWER: a 9. You can create a version of the _____ by illuminating a light-colored surface with a desk lamp and casting a shadow with a piece of paper. a. Hermann Grid b. Mach bands c. Benary Cross d. illusory square ANSWER: b 10. When _____, lateral inhibition can no longer account for the Hermann Grid. a. the lines are made curvy b. illumination is increased c. illumination is decreased d. the number of squares is increased ANSWER: a 11. The inability of lateral inhibition to account for more complex effects shows how _____. a. physiological explanations may need to be modified by perceptual results b. physiological explanations rarely hold across species c. perceptual explanations are typically consistent across species Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing d. what we learn from animals is rarely applicable to humans ANSWER: a 12. The inability of lateral inhibition to explain some perceptual effects suggests that some contrast effects are based in _____. a. the retina. b. the cortex c. the lateral plexus d. the macula ANSWER: b 13. The area on the retina that influences the firing rate of the neuron is called the _____. a. receptive field b. amacrine region c. divergence area d. inverted fovea ANSWER: a 14. A neuron with an excitatory center-inhibitory surround receptive field will respond most when we stimulate _____. a. only the center b. only the surround c. both the center and surround together d. part of the surround ANSWER: a 15. Most of the signals travel from the retina to the _____ via the optic nerve. a. temporal cortex b. lateral geniculate nucleus c. the superior colliculus d. the visual homunculus ANSWER: b 16. Chad is reading when he sees an insect land on the corner of his book. He then makes an eye movement to look at the insect. The structure of the visual system that is most likely responsible for making this eye movement is the _____. a. superior colliculus b. extrastriate cortex c. optic chiasm d. parietal cortex ANSWER: a Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing 17. Neurons in the LGN have _____ receptive fields. a. center-surround b. side-by-side columnar c. ill-defined d. ambiguous ANSWER: a 18. The flow of information in the LGN is best described as _____. a. unidirectional, with signals going from the retina to the LGN b. unidirectional, with signals going from the LGN to the retina c. unidirectional, with signals going from the LGN to the cortex d. signals coming from the retina and the cortex to the LGN ANSWER: d 19. The flow of information to the _____ from the _____ is greater than from the _____. a. cortex; LGN; retina b. LGN; retina; cortex c. retina; LGN; cortex d. LGN; cortex; retina ANSWER: d 20. The Nobel Prize winners who conducted the pioneering research on the physiology of striate cortex neurons were _____. a. White and Benary b. Hubel and Wiesel c. Mathers and Marshall d. Libby and Rizzutto ANSWER: b 21. Graphing the response of a simple cortical cell results in the _____. a. response compression curve b. orientation tuning curve c. response expansion curve d. motion-directive sensitivity function ANSWER: b 22. Unlike simple cells, complex cells respond best to _____. Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing a. stationary spots of light b. small spots of light c. moving stimuli d. stationary lines of any orientation ANSWER: c 23. ______ cells fire to moving lines of a specific length or to moving corners or angles. a. Complex b. Simplex c. Endstopped d. Edge ANSWER: c 24. As we travel farther from the retina, neurons fire to _____. a. more complex stimuli b. less complex stimuli c. more intense stimuli d. less intense stimuli ANSWER: a 25. The different types of cortical cells that respond to specific stimuli are also known as _____. a. inhibitory cells b. feature detectors c. direct circuits d. signal detectors ANSWER: b 26. A stimulus that contains alternating black and white bars is called a _____. a. grating b. grid c. Boolean array d. Moire pattern ANSWER: a 27. The difference in intensity between light bars and dark bars is called a. orientatio n b. wave form Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing c. phase d. contrast ANSWER: d 28. To measure _____, the experimenter decreases the intensity difference between the light bars and the dark bars until an observer can just barely detect the difference between the dark bars and the light bars. a. Mach bands b. contrast threshold c. phase continuity d. brightness constancy ANSWER: b 29. The results of experiments of selective adaptation to gratings with specific orientations can be related to the _____ of _____ cells. a. lateral inhibition; simple cortical b. lateral inhibition; end-stopped c. tuning curves; amacrine d. tuning curves; simple cortical ANSWER: d 30. When we view a stimulus with a specific property, neurons tuned to that property fire and will eventually become fatigued, an effect called _____ adaptation. a. selective b. refractor y c. depletion d. massed ANSWER: a 31. _____ refers to the fact that the response properties of neurons can be shaped by an animal’s or person’s perceptual experience. a. Selective adaptation b. Neural plasticity c. Sensory integration d. Perceptual analysis ANSWER: b 32. Selective rearing refers to _____. a. raising an organism in an environment that only contains certain types of stimuli b. genetically manipulating the organism prenatally c. genetically manipulating the organism in the first month after birth Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing d. presenting an array of stimuli to the organism in the first month after birth ANSWER: a 33. When a kitten is exposed to an environment of just horizontal lines, the kitten _____. a. would pay attention only to vertical lines b. would pay attention only to horizontal lines c. would have cortical cells that only respond to vertical lines d. would have cortical cells that respond to horizontal lines, but none to vertical lines ANSWER: d 34. In the 1990s, researchers discovered an area on the underside of the temporal lobe of the human cortex that was named the _____ face area because it responded strongly to faces. a. fusiform b. cingulate c. geniculat e d. occipital ANSWER: a 35. Neurons in the _____ respond to complex stimuli, but not simple stimuli such as straight lines. a. LGN b. striate cortex c. IT cortex d. retina ANSWER: c 36. Which proposed representational system is the least likely to actually be in place in the human visual system? a. sparse coding b. specificity coding c. representation by a small number of neurons d. distributed coding ANSWER: b 37. _____ coding is the representation of a particular object by the pattern of firing of a large number of neurons. a. Specificity b. Population c. Extrastriat e d. Sparse Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing ANSWER: b 38. Quiroga et al. (2008) studied sensory coding by _____. a. ablation of the IT in humans b. ablation of the FFA in humans c. using implanted electrodes in the limbic system of college student volunteers d. using implanted electrodes in the temporal lobe of epileptic patients ANSWER: d 39. _____ coding occurs when a particular object is represented by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent. a. Sparse b. Selectiv e c. Limited d. Specific ANSWER: a 40. In _____ coding, a particular neuron might respond to Jason’s face, another particular neuron to Sam’s face, and another particular neuron to Bill’s face. a. identity b. specificity c. individuated d. experiential ANSWER: b Essay 41. (a) What is lateral inhibition? (b) Select either the Hermann Grid or Mach bands, and discuss how lateral inhibition accounts for the phenomenon. ANSWER Lateral inhibition is inhibition that is transmitted across the retina. Explanations will : vary, but should focus on the effects of summing lateral inhibition over a circuit. 42. What happens when the straight lines of the Hermann Grid are made curvy? Why is this a problem? ANSWER When the grid’s usual straight lines are made curvy, the dark spots at the intersections : vanish! But making the lines curvy should have little or no effect on lateral inhibition. So a simple perceptual display has called into question an explanation that has been accepted for many years. Of course, the next question is, what is the mechanism responsible for these effects? A number of alternatives have been proposed involving interactions between neurons that are more complex than the simple lateral inhibition calculations, but these explanations are unproven, so further research will be needed to determine exactly what is going on. 43. Describe Hartline’s procedure for mapping receptive fields. Copyright Cengage Learning. Powered by Cognero.

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Chapter 03: Neural Processing ANSWER Hartline isolated a single fiber in the optic nerve of a frog by teasing apart the optic : nerve near where it leaves the eye. While recording from this teased-out fiber, Hartline illuminated different areas of the retina and found that the fiber he was recording from responded only when a small area of the retina was illuminated. He called the area that caused the neuron to fire the nerve fiber’s receptive field, which he defined as “the region of the retina that must receive illumination in order to obtain a response in any given fiber.” 44. (a) Describe the difference between simple cortical cells, complex cortical cells, and end-stopped cells. (b) Explain why these cells are called “feature detectors.” ANSWER Cells with side-by-side excitatory and inhibitory receptive fields are called simple : cortical cells. Complex cells, like simple cells, respond best to bars of a particular orientation. However, unlike simple cells, which respond to small spots of light or to stationary stimuli, most complex cells respond only when a correctly oriented bar of light moves across the entire receptive field. End-stopped cells fire to moving lines of a specific length or to moving corners or angles. Because simple, complex, and endstopped cells fire in response to specific features of the stimulus, such as orientation or direction of movement, they have been called feature detectors. 45. Discuss the relationship between neural plasticity and selective rearing as it relates to sensory functioning. ANSWER The idea behind selective rearing is that if an animal is reared in an environment that : contains only certain types of stimuli, then neurons that respond to these stimuli will become more prevalent. This follows from a phenomenon called neural plasticity or experience-dependent plasticity, i.e., the idea that the response properties of neurons can be shaped by perceptual experience. When animals are reared in an environment that, for example, contains only vertical lines, neurons that respond to vertical lines will come to dominate. 46. Describe how information would be represented under each of the following representational schemes: specificity coding, population coding, and sparse coding. ANSWER The idea that an object could be represented by the firing of a specialized neuron that : responds only to that object is called specificity coding. Population coding is the representation of a particular object by the pattern of firing of a large number of neurons. Sparse coding occurs when a particular object is represented by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent.

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