University of California, Berkeley
Department of Psychology

Psychology 1
Summer 2011

Midterm Examination 1

## Scoring Key and Item Analysis

In the scoring key that follows, correct answers are marked with double pound signs (##).

The average score on the exam, before rescoring, was 67.52% correct, which was within the historical range of 65-70% correct on exams in Psych 1.

Following procedures outlined in the Exam Information page, the statistical analysis identified three (3) bad items, #s 14, 23, and 46. Both items were rescored correct for all responses. No other items will be rescored.

The average score on the exam, after rescoring, was 34.76, with a standard deviation of 6.70, or 70% correct, which is pretty good by historical standards.

The exam scores entered into the ANGEL gradebook already reflect this rescoring. Because of the rescoring, many students will notice that the exam score posted to the gradebook grade is higher, by 1-3 points, than the initial score they received as feedback when they submitted their exam.

In what follows, I provide the percentage of the class that got each item correct, as well as the item-to-total correlation (rpb)for each item. I also include commentary on why the right answer is right, and the others wrong.

Choose the best answer to each of the following 50 questions. Questions are drawn from the text and lectures in roughly equal proportions, with the understanding that there is considerable overlap between the two sources. Usually, only one question is drawn from each major section of each chapter of the required readings; again, sometimes this question also draws on material discussed in class. Read the entire exam through before answering any questions: sometimes one question will help you answer another one.

Most questions can be correctly answered in one of two ways: (1) by fact-retrieval, meaning that you remember the answer from your reading of the text or listening to the lecture; or (2) inference, meaning that you can infer the answer from some general principle discussed in the text or lecture. If you cannot determine the correct answer by either of these methods, try to eliminate at least one option as clearly wrong: this maximizes the likelihood that you will get the correct answer by chance. Also, go with your intuitions: if you have actually done the assigned readings and attended the lectures, your "informed guesses" will likely be right more often than they are wrong.

Correct answers are marked with ##.

1. Why did many philosophers consider psychology to be an 'impossible' science?

a. They believed that, because mind was different from body, mental states could not be measured. ##

b. They believed that neural processes accounted completely for behavior.

c. They believed in reductionism.

d. They believed that only sensory experience could be studied under conditions of strict experimental control.

90.6% of the class got this question correct; item-to-total rpb = .35. Psychology is a science of mental processes, and at its inception the prevailing thought was that the mind and the body were entirely separate. Unlike today, no inferences about the mind were made from behavior. Philosophers (such as Kant) thought that since science is based on measurement, and mental states aren't measurable, and mental states weren't available for study, that psychology could never be a science. [Lecture 1]

2. A typical human cell has ___________ genes as the roundworm (C. elegans).

c. about the same number of ##

56.3% correct; rpb = .39. Before the human genome was sequenced, it was believed that an organism as complex as humans must have more genes than more simple animals. In fact, scientists had anticipated that we would have 4 to 5 times more genes than we actually have. However, a human cell has about 20-30,000 genes, and a C. elegans cell has about 20,000 as well. [Chapter 2]

3. In evolutionary theory, proximate causes refer to the _____ while ultimate causes refer to _____.

a. mechanisms within an organism's life; mechanisms within a population over many generations ##

b. mechanisms within a population over many generations; mechanisms within an organism's life

c. local cause of a trait; the final causation for a trait

d. the final causation for a trait; the local cause of a trait

65.6%; .39. Proximate causes are the mechanisms within the organism's lifetime that lead to its individual phenotype (for example, the proximate causes of intelligence might be SES or nutrition). Ultimate causes are the reasons why a species' trait might have been adaptive for survival and reproduction and therefore exist, but are not necessarily influenced by the current environment (for example, humans as a species have evolved specific forms of intelligence that other species have not). [Chapter 2]

4. Which of the following is NOT an example of niche construction in humans?

a. building new shelters

b. finding new sources of food

c. creating social alliances

d. highly stereotyped fear behavior ##

79.2%; .41. Niche construction is the process in which organisms alter the environment and create their own circumstances, rather than just reacting in a pre-defined fashion. Stereotypies are by definition not flexible and do not function to specifically change an organism's environment. Finding food, meeting people and building structures all alterations to an environment. [Chapter 2]

5. Heritability ratios for human intelligence suggests that the degree of heritability _____.

a. depends on the group being considered

b. depends on the environment being considered

c. depends on both the group and environment being considered ##

d. is stable and does not change across groups

68.8%; .11 Heritability is a measure of the degree to which genes influence a particular trait for a given population of people, taking into account the environment's influence. The ratio will change when the environment changes, and/or when the genetic variability of a population changes. For example, one study estimated the heritability of intelligence in a middle class sample to be 70%, whereas in a low SES group, heritability was close to zero. [Chapter 2]

6. Why do female mammals choose the mate in most species?

a. Reproduction places a huge burden on the mammalian female. ##

b. Female mammals are better at choosing than males.

c. Males are careless when it comes to mate selection.

d. All of the above.

75.0%; .32. The female is the individual who has more investment in her reproduction (larger gamete size, the giving of physical nourishment during gestation and nursing which she has to generate, and the care of young for comparatively extended periods, often at the cost to her own activities), and therefore has a limited number of offspring she can produce in a lifetime. It is in her own best interests, given these limits, to pick partners that are the best available, to ensure that this large investment has the best chance of surviving and passing on her genes. [Chapter 2]

7. _____ are bundles of neurons that conduct excitation from the brain or spinal cord.

a. Receptors

b. Effectors

c. Efferent nerves ##

d. Afferent nerves

7.9%; .37. Since the direction given is from brain to spinal cord, these would be efferent nerves, or those that extend away from the brain as opposed to back to it. One way to remember is to think of the 'e' as standing for 'exit.' Receptors are parts of the neurons themselves, and receive messages from neighboring neurons; they are not bundles of neurons. [Chapter 3]

8. Agonist is to _____ as antagonist is to _____.

a. reducing the action of a neurotransmitter; increasing the action of a neurotransmitter

b. increasing the action of a neurotransmitter; reducing the action of a neurotransmitter ##

c. destroying the neurotransmitter; creating a neurotransmitter

d. creating a neurotransmitter; destroying a neurotransmitter

90.6%; .20. Definitional question. One way to remember the difference between the two terms is to note that antagonist has the common prefix 'ant,' which denotes an opposing or resisting force. Agonists potentiate, or increase effects and so by contrast, an 'antagonist' will reduce or inhibit it. Neither term means create or destroy. [Chapter 3]

9. Which is one of the functions of the cerebral spinal fluid?

a. to act as a shock absorber for the brain when the head moves abruptly ##

b. to keep the brain and spinal cord moist

c. to increase the function of hormones in the CNS

d. all of the above

56.3%; .02. The cerebral spinal fluid acts as a shock absorber for the brain, absorbing force generated by abrupt movements of the head. It is a cushion that provides basic mechanical protection. It does not increase hormonal function. [Chapter 3]

10. The brain seems to consist of a large number of separate and specialized modules. There is, in other words, a localization of brain function. At the same time, research also has shown that _____.

a. the module that performs certain tasks varies from person to person

b. there are no links from one module to another

c. multiple brain areas are activated for any task we do ##

d. all of the above are correct answers

83.3%; .37. The brain, while modular, is highly interconnected and functions cooperatively. This means that many areas will be activated for any given task. For example, though we produce language largely in Broca's area, we also have to involve the sensory areas that move our tongues, the regulatory areas that arrange our breathing and we have to focus our attention on what we are doing and saying. This involves many brain areas, and these areas do not vary from person to person, but are instead anatomically consistent. [Chapter 3]

11. The region of the brain closest to Broca's area is the _____.

a. motor representation for the hand

b. somatosensory representation for the hand

c. motor representation for the tongue ##

d. somatosensory representation for the tongue

74.0%; .37. Since Broca's area is related to language production, and since most languages involve the use of the tongue, the area closest would be the region that governs the motor performance of the tongue. The hands are not usually involved in the production of language, and are therefore not as closely situated and connected to Broca's area. [Chapter 3]

12. One of the central findings of brain research, whether based on clinical observation or neuroimaging studies, is that the _____.

a. brain is incapable of self-repair

b. brain is set up holistically: any part can perform any function, if needed

c. individual parts of the nervous system are each highly specialized ##

d. brain cannot form new connections after age 15

61.5%; -.02. Research clearly shows that the brain is capable of repair in limited circumstances. For example, stroke and trauma patients often recover some of their lost function with time and effort, demonstrating that at least some repair is possible. The brain is not limitlessly malleable, though, and has specialized modules that perform clearly-defined functions. Lastly, the brain forms new connections throughout life; indeed, all learning is about creating new synaptic connections, and learning is something that has no predefined termination point. [Chapter 3]

13. In the autonomic nervous system:

a. the sympathetic branch is responsible for homeostatic regulation.

b. interneurons connect the 31 spinal nerves with the 12 cranial nerves.

c. the parasympathetic branch is characterized by slow onset and slow offset. ##

d. blood flow is redirected from the muscles to the surface of the body.

67.7%; .49. The autonomic nervous system is responsible for non-voluntary body actions (such as sweating, digestion etc.), primarily through acting on the internal organs. It has two branches: the sympathetic and parasympathetic nervous system. The SNS readies the body for activity, and the PNS responds more slowly, helping the body rest and restore homeostasis. Readying for action happens quickly, but returning to a resting state takes longer. [Lecture 2]

14. Patients in a coma:

a. show some reflex functions.

b. are totally unresponsive to stimulation. ##

c. continue to show the normal sleep-wake cycle

d. can respond only through eye movements.

46.9%, .11, a bad item. Coma is caused by damage to the reticular formation, meaning no sensory information can enter the brain at all. Patients in a coma would be unable to respond to any sensory stimulation or be able to produce voluntary movement. Since they are not asleep, they do not have sleep-wake cycles. On the other hand, some coma patients may show some spinal reflexes (though not the pupillary reflex, which is mediated by cranial nerves. [Lecture 3]

15. A patient with 'receptive' aphasia would most likely show brain damage in the _____ lobe.

a. frontal

b. temporal ##

c. occipital

d. limbic

83.3%, .26. Aphasia refers to language impairment, and 'receptive' means taking in sensory info. The temporal lobe is the one associated with speech reception, so this is probably the area most likely damaged in receptive aphasia. Limbic systems govern emotional processing, occipital regions process vision, and your frontal lobes are more associated with executive function like planning, regulation and inhibition. [Lecture 4]

16. Lashley's 'Law of Mass Action' states that

a. following a closed head injury, the entire brain oscillates inside the skull, creating extensive damage.

b. complex cognitive functions like language require the entire brain.

c. learning is mediated by the cerebral cortex as a whole. ##

d. specific items of knowledge are localized in discrete bundles of neurons.

69.8%, .32. Lashley's law says the degree of memory impairment is related to the extent of cortical damage, but not to the location of the damage. A is incorrect because Lashley's law doesn't discuss the specifics of how any given damage occurs. B is incorrect because it is known that the brain is modular, and that the temporal lobe is associated with language. D is incorrect because knowledge is distributed widely in the cortex, over entire systems of neurons, and is preserved if enough of the network is preserved. [Lecture 5]

17. A study is considered internally valid if _____.

a. the experimental and control groups are treated differently from one another, except for experimental manipulation

b. all confounds have been measured

c. the experimental and control groups are treated identically, including experimental manipulation

d. all confounds have been eliminated ##

53.1%, .46. There are several types of validity. Remember that internal validity refers to the causal relationship between two variables being properly demonstrated. If all confounds have been eliminated, then we can be sure that any effects found in the study are due to the experimental manipulation, rather than to some other confounding variable, and this means that the study is internally valid. A is incorrect because the two groups should be treated the same except for the manipulation; B is incorrect because though it is helpful to measure confounds, real validity comes from eliminating them altogether; C is incorrect because the experimental manipulation should be given only to the experimental group, not to the control group. [Chapter 1]

18. In a correlational study of level of education and level of depression, the investigators are trying to observe the relationship between these two variables. This type of study would differ from experimental studies in several important respects. For instance, _____.

a. in correlational studies, it is difficult to determine what is causing what

b. correlational studies can suffer from what is called the third-variable problem

c. random assignment is not an option in correlational studies

d. all of the above are correct ##

83.3%, .47. All of these are true of correlational studies. In these studies, there is no experimental manipulation; we simply measure different variables and see how they relate. Because there is no manipulation, correlation does not establish causation; a third (unmeasured) variable may be causing the relation between the two that are measured, and by definition correlational studies don't involve random assignment, which is part of experimental manipulation. [Chapter 1]

19. In a quasi experimental study, the groups _____.

a. were randomly assigned

b. likely exist independent of the research study ##

c. always involve studies investigating gender effects

d. typically investigate aggression

72.9%, .38. Remember that a quasi-experiment differs from an experiment in that an experiment randomly assigns participants to treatment groups, but in a quasi-experiment this is not done for some reason, often because it is impossible (e.g., you can't randomly assign a person to have one gender or the other) or because it is unethical (e.g., you can't randomly assign children to either be maltreated or not). Thus, in a quasi-experiment, researchers compare groups that already existed independent of the research study (e.g., men and women; maltreated versus non-maltreated children). These studies thus may involve gender effects, but they do not always do so. [Chapter 1]

20. Let's say you want to assess the effect of subliminal suggestions on ratings of attractiveness. You ask 20 students to listen to subliminal tapes and then have them rate the attractiveness of 20 peers. You discover that all the peers were rated as highly attractive, with a mean of 8 out of a possible 10. Why is the above experimental design inadequate?

a. It lacks demand characteristics.

b. It lacks an independent variable.

c. It lacks a dependent variable.

d. It lacks a control group. ##

87.5%, .45. A is incorrect because demand characteristics are things to avoid having in a study, and therefore lacking them would not make the study inadequate. B is incorrect: the IV is hearing the subliminal tapes. C is incorrect: the DV is attractiveness ratings. The problem with the study is lack of control group: everyone heard the tapes, and thus we don't know how the peers' attractiveness would have been rated by students who had not heard them. [Chapter 1]

21. Deception _____.

a. can never be used in psychological research because of ethical concerns

b. is used in most psychological research

c. should be minimized for ethical reasons and followed by careful debriefing ##

d. is not a problem for psychological research because all subjects are debriefed

66.7%, .23. Deception is allowed in research, but only rarely, only if there is no other good way to answer the research question, and only if it would not pose more than minimal risk to participants. Thus, it can be used in research, but is not used in most research, and should never be considered 'not a problem,' even if subjects are debriefed, because of the potential risk to participants. [Chapter 1]

22. A particular test of extraversion has a mean score of 100 and a standard deviation of 10. Jake scores 120 on this test. This means that Jake is more extraverted than _____ of the population.

a. 20%

b. 50%

c. 68%

c. 97% ##

58.3%, .43. If the standard deviation is 10, then Jake is two standard deviations away from the average person. According to the rule of 68, 95, and 99, 95% of the population lies within 1 standard deviation of the mean, but this 95% has to be split, half (47.5%) above and half (the other 47.5%) below the mean. So, if Jake scores 120, then he scores higher than 50% (all those who lie below the mean) plus 47.5% (those who lie two standard deviations above the mean) of the population. Thus, Jake scores higher than about 97% of the population. One standard deviation above is 34%, the second adds 13.5%; this adds to 47.5%. But, remember that you must also add the 50% of the population that falls below the mean. Thus, Jake's score puts him at the 97th percentile for extraversion. [Lecture 6]

23. What is the adaptive significance of habituation?

a. It greatly intensifies the effects of sensitization.

b. It allows organisms to ignore familiar but harmless stimuli. ##

c. It paves the way for associative conditioning.

d. It keeps neurons active when they might otherwise degenerate.

29.2%, .21, bad item.The intended correct answer was B. But when the exam was transcribed into ANGEL, an error was made in which option A was copied over into option B as well. Because the correct answer, B, was not available, we rescored this item correct for all responses. Anyway, stimulation is constant in the life of an organism, and it would be difficult to attend to everything, trying to sort out what is meaningful and what isn't for everything you can perceive. It is much more adaptive to be able to determine that some stimuli are not to be attended to and then to stop responding, saving responses and attention for stimuli that are more meaningful. You cannot associate events that you have stopped responding to, so C cannot be right, and habituation is the opposite of sensitization, which means an organism responds more acutely to stimuli. [Chapter 7]

24. Surprise appears to play an important role in classical conditioning. In terms of surprise, which of the following is most important if effective conditioning is to occur?

a. the extent to which the US is surprising ##

b. the extent to which the UR is surprising

c. the extent to which the CR is reflexive

d. the extent to which the UR provides redundant information

68.8%, .52. In all cases, conditioning depends on whether the probability of the US after the CS is different from the probability of the US without the CS. The more unlikely it is that you receive, say, food, after an event, the more it stands out in your mind and can be paired with the preceding event, creating a stronger expectation. If the food is surprising, you remember the conditions under which it appeared. If you just expect it, then receiving it makes less of an impact. Your own UR being surprising should have no bearing, as it's not variable. [Chapter 7]

25. In an experiment, a dog undergoes 20 trials in which he hears a tone and gets meat powder in various combinations. On 18 of the trials, he gets a tone and meat powder; on one trial, he gets a tone and no meat powder; and on one trial, he gets meat powder and no tone. What is true of this situation?

a. There is a contingency between the sound of tone and meat powder. ##

b. There is a contingency between the CS and the UR.

c. There is a negative contingency.

d. There is no contingency.

55.2%, .30. As long as there is a majority of trials associating two events together, there high a high likelihood of an association, making these two elements contingent. Since there is no mention of an unconditioned response (salivation, presumably), B cannot be correct. Negative contingencies are when something will not occur, and since both are presented, this would be false, and though there is one trial where the two elements are not linked together, it is not enough to influence the phenomenon that the 18 other trials have established. [Chapter 7]

26. When you gamble, there is no way to tell which of your many responses will bring a reward. Gambling, therefore, is an example of _____.

a. a variable-ratio reinforcement schedule ##

b. a fixed-ratio reinforcement schedule

c. a variable-interval reinforcement schedule

d. a fixed-interval reinforcement schedule

72.9%, .29. A fixed-interval schedule says that you'll be rewarded after an exact amount of time has gone by no matter how many responses you give in that time (gambling isn't a timed event); a variable-interval schedule says that you'll be rewarded after an average amount of time has gone by, again, irrespective of responses (checking email, for example); a fixed-ratio is when you get rewarded after an exact number of responses (you get a bonus after every 5th gadget you sell), and a variable-ratio means you get rewarded after an number of responses somewhere around a set average. Slot machines have a set probability of when they'll payout, so you have to have a variable number of responses until it does. [Chapter 7]

27. What does latent learning show?

a. Learning can occur without behavioral change. ##

b. Learning can occur suddenly, in a single trial.

c. Learning will not occur if blocking is present.

d. Learning requires a certain amount of response control.

82.3%, .50. Latent learning means learning that isn't demonstrated until such a time that the eliciting stimulus is presented, even though the learning itself took place during a previous event. It does not have the constraint that it happen in a single trial, only that it isn't demonstrated while in the learning phase. Blocking is not a part of latent learning specifically, and since there is no response initially, response control isn't an issue. Remember the experiments with rats in a maze that, while not receiving any rewards for exploring, still learned the layout of the maze that they then could use in subsequent trials. [Chapter 7]

28. According to the principle of preparedness or belongingness, which of the following would be the most difficult to do?

a. training a pigeon to flap its wings to avoid shock

b. training a rat to associate a flashing light with nausea ##

c. training a pigeon to peck a piano key to get a food reward

d. training a cat to rub your legs to get you to open a can of cat food

65.6%, .43. The principle of belongingness says that some things will be more easily learned than other things, due to their evolutionary significance in function. Avoiding shock by flying away makes sense, and so is easy to teach. Similarly, birds peck to get food in their natural environment, and cats rub up against owners' legs before being fed. These are all behaviors that are connected to food acquisition already, and so reinforcing them is a relatively simple matter. However, flashing lights aren't inherently linked to food acquisition in the rat, and the association between lights and subsequent nausea caused by eating food isn't one the rat can therefore easily make. There is no 'natural' connection between lights and food, and so the rat isn't 'prepared' to make that mental connection. [Chapter 7]

29. What is one limitation on innate responses to stimulation, such as instincts or fixed action patterns?

a. they involve only single muscles, or small groups of muscles, as opposed to the entire skeletal musculature.

b. evolution does not permit individual organisms to respond to changing environments. ##

c. they only control the behavior of invertebrates, and are lacking in vertebrates.

d. Innate responses cannot generalize from one individual species member to another.

59.4%, .51. Evolutionary changes are slow, while environments change quickly. Since a fixed action pattern is determined by something innate to the organism, it cannot be changed as easily as the environment can be. They vary widely, however, and can be complex behaviors such as nest building (insects) and are not limited to invertebrates. They cannot be transmitted to other organisms, but since they are in all of the members of that species, it is not a limitation. [Lecture 7]

30. What is an implication of spontaneous recovery?

a. Extinction can never completely succeed.

b. Extinguished responses are suppressed rather than lost from the organism's repertoire. ##

c. The acquisition of a conditioned response is subject to time-induced forgetting.

d. Re-acquisition of a CR proceeds more slowly than the original acquisition phase.

77.1%, .24. That a behavior can spontaneously recover demonstrates that it's not forgotten, but rather suppressed. Extinction can eventually succeed, but you have to keep it going for an extended period of time, to extinguish 'beyond zero' and so that no savings in learning is demonstrated. If there is a savings, relearning will happen much more quickly. [Lecture 8]

31. Instrumental conditioning differs from classical conditioning in that:

a. In instrumental conditioning, reinforcement is contingent on the organism's behavior. ##

b. In classical conditioning, the CR is 'voluntary' behavior, freely emitted by the organism.

c. Relatively few behaviors are subject to instrumental conditioning.

d. Classical conditioning cannot control reflexive behaviors.

81.3%, .38. Instrumental (or 'operant') conditioning relies on consequences being connected to behavior, thus making that behavior more likely to recur in the future. B cannot be right because in classical conditioning the behavior emitted is not under voluntary control (salivation, heart rate increase). C cannot be right because just about any behavior you can do voluntarily is subject to instrumental conditioning, and D says that classical conditioning cannot control reflexive behavior when the opposite is actually true. [Lecture 9]

32. In observational learning:.

a. Animals learn to imitate the behavior of others in order to gain reinforcement.

b. Reinforcement is not critical to learning. ##

c. Hunger is the most important motive for learning.

d. Exposure has no effect on learning in the absence of some motivational state.

26.0%, .24. In observational learning, the mechanism of action is watching another organism receive reinforcement or punishment, and inferring from that, rather than experiencing that consequence yourself. It isn't just the imitation of others that distinguishes it, but the lack of receipt of the consequence. Hunger isn't crucial, because food isn't the only reinforcement one can receive. [Lecture 10]

33. The philosopher Immanuel Kant (1724'1804) held the position that perception is only possible because the mind _____.

a. is made up of cells with their own receptive fields

b. associates different sensory experiences into coherent wholes

c. organizes sensory information into preexisting categories ##

d. lacks the capacity for 'turning off' the visual world

71.9%, .27. Kant argued that perception is possible only because we organize sensory information into preexisting categories, and that we have an innate grasp of spatial, temporal and causal relationships built in as a framework. Kant didn't know about cells, and his position was not specific to visual stimulation, so A and D don't work. B is close, but Kant's main point was that the mind already has preexisting categories into which to put sensory info, not that we organize it as it comes in. [Chapter 4]

34. The smaller the Weber fraction, _____.

a. the less sensitive the sense modality

b. the higher the response criterion

c. the more sensitive the sense modality ##

d. the shorter the duration of response to any sensory impression

71.9%, .33. Weber's law allows us to compare the sensitivities of different sensory modalities which are difficult to compare otherwise (for example, is the ear 'as sensitive' to sound as the eye is to light?). Since the equation is 'change in intensity over intensity,' the smaller the number, the lower the threshold for detection is, and therefore the more sensitive that sense is. [Chapter 4]

35. What is true of signal-detection theory?

a. Signal-detection theory allows one to separate actual perceptual ability from response tendencies. ##

b. Signal-detection theory suggests that, for each subject, there exists a constant stimulus intensity corresponding to a zero stimulus.

c. Signal-detection theory suggests that perceived sensation occurs only in the presence of an external stimulus.

d. Signal-detection theory suggests that confusion about whether or not a stimulus has been presented is most likely to occur when the signal is much greater than the noise.

55.2%, .54. B is not correct because signal detection theory allows that a given subject will sometimes detect low-level stimuli and sometimes not; their performance will not be constant. C is not correct because it has a category for 'false alarms,' in which the subject thinks they have detected a signal when there was no signal. D is not correct; this should be reversed ' confusion grows as the noise becomes much greater than the signal; a strong signal in low noise is easy to detect. A is one of the basic ideas of signal detection theory; by separating hits, misses, correct rejections, and false alarms, it can separate a subject's sensitivity to the signal from their tendency to respond either positively or negatively when they are unsure of the signal. [Chapter 4]

36. Emotional processing of pain occurs in the _____ while the processing of the actual sensation of pain occurs in the _____.

a. C-fiber; A-delta fiber

b. A-delta fiber; anterior cingulated cortex

c. anterior cingulate cortex; somatosensory cortex ##

d. C-fiber; somatosensory cortex

53.1%, .31. Recall that the anterior cingulated cortex is a part of the limbic system, which processes emotions. The somatosensory cortex, in contrast, processes bodily sensations. The A-delta fibers and C-fibers transmit the sensation of pain from the tissues, but that happens prior to processing. Processing happens once the brain has received the signal! [Chapter 4]

37. According to place theory, what structure in the human ear moves in different locations in response to different sound frequencies?

a. the ossicles

b. the eardrum

c. the oval window

d. the basilar membrane ##

85.4%, .51. Remember that the basilar membrane is the part of the inner ear, inside the cochlea, which deforms in response to movement of inner ear fluid. This deformation stimulates the hair cells that send auditory signals to the brain. The cochlea is a long, wound-up tube, and the basilar membrane stretches down the middle of its length. Place theory states that sounds of different frequencies will deform only particular places along the length of the basilar membrane, stimulating only certain hair cells, and this is how the brain is able to perceive pitch. The ossicles, eardrum and oval window can't move in 'different locations.' [Chapter 4]

38. What can be said of an object that is seen out of the corner of one's eye (i.e., in one's peripheral vision)?

a. It is clearest when seen in infrared light.

b. It can be seen only at night.

c. It activates the opponent-color system.

d. It primarily stimulates the perceiver's rod vision. ##

85.4%, .23. Cones are for color, and are concentrated in the fovea (center of the retina). Rods respond only to light level, and are more plentiful in non-central areas of the retina, which constitute our peripheral vision, therefore anything seen peripherally would be utilizing rods. [Chapter 4

39. You are shown the character '1'. When presented in the figure 2,134, you call it the number 'one'; when it is presented in the word 'lift' you call it the letter 'L.' Why do you perceive it differently across the two situations when the actual character has not changed?

a. You have learned two names for the character.

b. You perceive that the context '2,134' is different from the context 'lift'.

c. Because you are a skilled reader, you can perceive the subtle differences in the shape of the character.

d. Both a and b. ##

83.3%, .33. C is incorrect because this will work even when the character is exactly the same shape. Context powerfully affects how we interpret what we see, and when we have learned more than one name or use for a character, the context will tell us how to perceive that character in order to make sense of the scene. 2,L34 does not make sense, and thus the brain will not perceive the ambiguous character '1' as an L. Context is an important shaper of our responses. [Chapter 5]

40. A patient suffers from damage to the pathway between her occipital cortex and her temporal cortex. What task will she most likely have difficulty with?

a. identifying an object ##

b. reaching for an object

c. seeing an object

d. keeping track of time

62.5%, .45. The occipital cortex is associated with vision, and the temporal with language. Thus, if the pathway between these lobes is damaged, a patient may have trouble applying a verbal label to something she sees. Reaching involves the motor cortex, seeing involves only the occipital, and time is not related to either structure, though the label might have tricked you; in this example, only the path between 'seeing' and 'language' has been itself damaged, so only naming or identifying an object would likely be affected. [Chapter 5]

41. Objects A and B both cast the same size image on your retina, yet distance cues indicate that A is closer to you. Which of the following will you perceive to be true?

a. A is larger than B.

b. A is smaller than B. ##

c. A and B are objects of the same size, at different distances from you.

d. A and B are objects of the same size, at the same distance from you.

72.9%, .35. The brain integrates distance and size cues to determine the relative sizes and distances of two objects. If distance cues clearly indicate that one object is closer, the brain must attribute the same-sized retinal images to a difference in actual size between the objects. Far-away images that are the 'same size' as close ones must therefore be bigger in reality. [Chapter 5]

42. Which of the following best describes the phenomenon of motion parallax?

a. Points closer than the target of our gaze seem to be moving in the opposite direction to us, while points beyond the target of our gaze appear to be moving in the same direction as we are. ##

b. Points closer than the target of our gaze appear to be moving in the same direction as we are, while points beyond the target of our gaze seem to be moving in the opposite direction to us.

c. As we approach an object, it appears to grow in size. As we move away from it, it appears to get smaller.

d. As we approach an object, the image gets sharper. As we move away from an object, the image gets fuzzier.

55.2%, .43. Remember that motion parallax happens when you are moving, and see things going by. If you focus your gaze at any one point in the distance, the things closer to you than that point will appear to move in the opposite direction, and the things farther away than that point will appear to move forward with you. And while C and D can happen, it isn't a part of the motion parallax. [Chapter 5]

43. What would happen if you suddenly experienced an involuntary twitch of one of your eye muscles?

a. The world would seem to move. ##

b. The world would remain stationary.

c. There would be a momentary 'blank' time in your perceptual experience.

d. You would experience motion parallax and optic flow.

59.4%, .39. The brain 'filters out' voluntary movement of the eye muscles when it is perceiving motion in the world, but involuntary eye movements would be perceived by the brain as actual movement in the world. When your eye moves voluntarily your brain expects the same shift in vision and that 'cancels out' the perception of movement. If you move involuntarily, the brain is not expecting the movement and there is no cancellation. [Chapter 5]

44. What is suggested by research in which subjects are asked to take part in a dichotic listening test, in which different stimuli are delivered to each ear?

a. The auditory stimulus is received by the receptors in the unattended-to ear, but the information is only partly processed. ##

b. The auditory stimulus is completely blocked out of the unattended-to ear.

c. The auditory stimulus in the unattended-to ear and the attended-to ear are both blocked out.

d. The auditory stimulus in the unattended-to ear and the attended-to ear are both clearly received and attended to.

50.0%, .48. Attention is serial. We really attend to only one thing at a time, and so other sensory information tends to be filtered out and only partially processed. But, the unattended-to information is not completely blocked out, because the sensory organ is still collecting information and sending it to the brain, where it is processed at least at a low level in the corresponding primary sensory area. [Chapter 5]

45. In sensation, transduction is accomplished by the:

a. proximal stimulus.

b. receptor organ. ##

c. sensory tract.

d. projection area.

55.2%, .43. Transduction is the transformation of a received stimulus to a neural impulse. The proximal stimulus is the sensory input that actually 'touches' the sensory organ: light waves, sound waves, etc. and so could not perform any transduction. The impulse is carried via the sensory tract to the projection area for that sense, but that is subsequent to transduction. [Lecture 11]

46. Which is not a problem with the Young-Helmholtz trichromatic theory of color vision?

a. Yellow can be created out of a mix of red and green. ##

b. Color blindness comes in two major forms.

c. There appear to be 7 primary colors.

d. Negative afterimages of color stimuli.

31.7%, .18, a bad item. The Young-Helmholtz theory says that any visible color can be produced by mixing the three primary colors corresponding to the three color cones (red, green and blue), so therefore yellow would be created by mixing red and green, using a subtractive process. Problems with the trichromatic theory include that color blindness can cause people to lose red/green, leaving yellow/blue, which would be impossible with three distinct receptors, and this and the existence of negative afterimages both support the opponent-process theory of color vision. [Lecture 12]

47. A subject in a signal-detection experiment has a hit rate of 80% and a false alarm rate of 75%. These values indicate that:

a. She is highly sensitive to the presence of the stimulus.

b. She has adopted a very conservative bias in responding.

c. She has adopted a very liberal bias in responding. ##

d. The experimenter has increased the proportion of catch trials in the payoff matrix.

81.3%, .41. Remember that both hits and false alarms happen when the subject indicates that they think they have indeed detected a stimulus. The fact that both of these numbers are high indicates that this subject says 'yes' a lot: a liberal bias. High sensitivity, as in a, would be reflected in a high hit rate but a low false alarm rate. A conservative bias, in b, would be reflected in both a lower hit rate. [Lecture 13]

48. According to Gibson's ecological view of perception:

a. Behaving organisms learn through experience to see the world the way it really is.

b. Perception of the environment is subject to all sorts of illusions and ambiguities.

c. Perception involves extracting information from the stimulus. ##

d. The perceiver must go 'beyond the information given' in the stimulus.

68.8%, .49. Gibson's view states that all information needed for a stimulus is provided by the environment. Humans see not only stimuli in the environment, we also provide top-down information that helps us make sense of what we see, so we do not 'see the world the way it really is,' making A incorrect. While perception is subject to illusions and ambiguities, this is not part of Gibson's ecological view. 'Going beyond,' and seeing illusions are part of the constructivist view. [Lecture 14]

49. The 'Gestalt' principles of perception pose a problem for Gibson's theory because:

a. Principles such as proximity and similarity violate the 'minimum principle' of perception.

b. They reveal a role for 'top-down' processing in perception. ##

c. They show that subjective contours cannot arise in perception.

d. They illustrate the role of 'bottom-up' processes in perception.

58.3%, .52. Gibson's view says all information needed for perception is supplied by the stimulus and it doesn't allow for any need for top-down processing, thus the Gestalt principles (e.g., continuity, closure, etc.) are a challenge to the theory, because for all of these principles, the stimulus does not contain all the features needed to perceive its 'gestalt.' [Lecture 15]

50. The constructivist view of perception:

a. is illustrated by the role of distance cues in the Muller-Lyer and Ponzo illusions.

b. holds that perception is intelligent problem-solving activity.

c. is consistent with Helmholtz' arguments concerning 'unconscious inferences' in perception.

d. all of the above. ##

74.0%, .45. The constructivist view of perception says that perception goes beyond the information given, and that we actively construct a mental representation of the world. The Illusions in answer A are a good illustration of this, since each of the lines are the same size, yet you don't perceive them as so. If you were seeing the world ecologically, or as it really is, there would be no illusion. Perception therefore is the taking in of the features available and solving the 'problem' they present of what they are, making inferences based on the information you take in through your senses. [Lecture 16]

A provisional answer key will be posted to the course website tomorrow.

The exam will be provisionally scored to identify and eliminate bad items.

The exam will then be rescored with bad items keyed correct for all responses.

Grades will be posted to the course website.

A final, revised, answer key, and analyses of the exam items,

will be posted on the course website after grades are posted.

Requests for rescoring must be received within

two (2) days of the posting of grades.

Each request should be accompanied by a paragraph

indicating why the answer given in the key is incorrect

or why the answer you chose was better.