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University of California, Berkeley

Department of Psychology

 Psychology 1

Summer 2014

 Midterm Examination 1


Scoring Key and Item Analysis

In the scoring key that follows, correct answers are marked with a double asterisk (**).

Two items were rescored.

  • Items #19 was miskeyed in Canvas.  The correct answer is D.  However, students who checked their grades before I had an opportunity to perform the item analysis, and who answered A (incorrectly), still got credit from Canvas.  So, we counted both A and D as correct.  But D is the only correct answer to this question.
  • The statistical analysis of this exam revealed just one (1) bad item, as defined in the Exam Information page: #23.  It was the only item with a relatively low pass percent and a low item-to-total correlation.  This item was rescored correct for all responses.
By statistical definition, they were difficult but fair.  So no items had to be rescored. 

Before rescoring, the mean score on the exam was 31.59 (63%), SD = 7.32.  This is pretty close to the usual range for my exams, which is 65-70% correct (again, see the Exam Information page).  The reliability of the exam was .86, which is excellent by psychometric standards.

After rescoring the mean score rose to 32.81 (66%), SD = 7.69.  Most students saw their scores increase by 1 or 2 points.  The figure at the left shows the distribution of scores.

In this feedback, I provide the percentage of the class that got each item correct and the item-to-total correlation (rpb) for each item, as well as 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.   


A provisional answer key will be posted to the course website tomorrow, after the window for the exam has closed. 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 on the rescored exam 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.   

1. The philosophical position that every behavior has a cause is known as

A. free will.

B. determinism.**

C. hereditarianism.

D. environmentalism.

90% of the class got this item correct; item-to-total correlation (rpb) = .28.  The doctrine of determinism states that the idea that every event has a cause, or determinant, that one could observe or measure. According to determinist assumption, everything we do has a cause. This approach assumes that we live in a universe of cause and effect. This is different from hereditarianism, which suggests that your behavior is only influenced by your heredity and experiences.  Chapter 1



2. The term “monism” refers to which belief?

A. People have the free will to decide their own destiny.

B. Children’s relationship with their parents influences their later social behavior.

C. People in cultures throughout the world have certain similarities in their behavior.

D. Brain activity and mental activity are the same thing.**

85% correct; rpb = .31.  Monism is the view that conscious experience is inseparable from the physical brain. That is, mental activity is brain activity. Consciousness can’t exist without brain activity, and it is presumably also true that certain kinds of brain activity can’t exist without consciousness.  Chapter 1



3. Why did other psychologists abandon Titchener’s interest in the structures of the mind?

A. They considered the question uninteresting.

B. They considered the question unanswerable. **

C. They considered his research unethical.

D. The government stopped funding research on this topic.

84%; .19.  Titchener’s structuralism is an attempt to describe the structures that compose the mind, particularly sensations, feelings, and images. For example, imaging you are the psychologist: I look at a lemon and try to describe my experience of its brightness to you separately from my experience of its yellowness. The problem with this approach is that we can’t trust that people’s reports are accurate reflection of the structure. Therefore, psychologists later abandoned his approach because it was neither interesting nor answerable.  Chapter 1



4.  Reductionism in psychology is the idea that

A. the ultimate causes of behavior have to do with genetics.

B. we should abandon psychological concepts in favor of biological ones.**

C. behavior should be explained by reference to the individual’s mental states.

D. It is impossible to achieve a truly scientific psychology, because some variables will always remain unexplained by science. 

38%; .39.  Reductionism holds that behavior can be explained in terms of biological (i.e., neural and endocrine) principles, without invoking mental states at all. This is different from mentalism, for instance, which suggests that mental (i.e., cognitive, emotional, or motivational states) stand in relation to action as cause and effect.  Lecture 1



5. The part of a neuron receiving messages is the ____. The part sending messages is the ___

A. axon ... cell body

B. cell body ... dendrites

C. axon ... dendrites

D. dendrites ... axon**

92%; .21.  A neuron consists of three parts: a cell body contains the nucleus of the cell. The dendrites are widely branching structures that receive input from other neurons. The axon is a single, long, thin, straight fiber with branches near its tip. As a rule, an axon transmits information to other cells, and the dendrites or cell body receives that information. The information can either be excitatory or inhibitory.  Chapter 3



6. If a drug prevents the inhibitory neurotransmitter GABA from attaching to its receptors, what happens to the postsynaptic cell?

A. It increases its production of new GABA molecules.

B. Its dendrites begin to shrink.

C. It produces more action potentials than usual. **

D. It creates additional GABA receptors.

67%; .19.  At each synapse, a neuron releases a chemical that either excites or inhibits the next neuron. That is, the chemical makes the next neuron either more or less likely to produce its own action potential. GABA is one neurotransmitter molecule that diffuses across a narrow gap to receptors on the postsynaptic neuron. A neurotransmitter fits into its receptor as a key fits into a lock, and it either excites or inhibits the postsynaptic neuron. Inhibitory synapses are important because it acts as a brake and activates your reflex.  Chapter 3



7. How do morphine, heroin, and other opiates affect the nervous system?

A. They distort the shape of the axon membrane.

B. They decrease the supply of blood to the cerebral cortex.

C. They increase the number of sodium ions in the brain.

D. They bind to receptors that use endorphins as their neurotransmitters. **

93%; .21.  Morphine, heroin and other opiates are narcotics that produce drowsiness, insensitivity to pain and decreased responsiveness. They stimulate endorphin synapses, decrease pain and binds to specific receptors in the brain. The discovery of neurotransmitter receptor demonstrated that opiates block pain in the brain, not in the skin. Neuroscientists then found that the brain produces several chemicals, called endorphins that bind to the opiate receptors.  Chapter 3



8. Damage or immaturity of which brain area is linked to impulsive decisions?

A. hypothalamus

B. prefrontal cortex**

C. occipital cortex

D. corpus callosum

89%; .25.  Unlike the occipital cortex, for instance, the prefrontal cortex is located in the forebrain that and is important for memory of what has just happened and what you are planning to do next. It is critical for decision making, especially for bypassing a current pleasure in favor of a greater pleasure later. People with impairments of the prefrontal cortex often make impulsive decisions because they have trouble imagining how good they might feel after one outcome and how sad or guilty they might feel after another. Chapter 3



9. What does the parasympathetic nervous system do?

A. It promotes digestion and other activities that occur during rest. **

B. It readies the body for vigorous fight or flight activities.

C. It controls movements of the skeletal muscles.

D. It integrates information from two or more sensory systems.

94%; .22.  Whereas the sympathetic nervous system readies the body for vigorous fight or flight activities, the parasympathetic system roughly perform the opposite functions. For instance, the parasympathetic nervous system is controlled by cells at the top and bottom levels of the spinal cord, decreases heart rate, increases digestive activities, and in general, promotes body activities that take place during rest and relaxation. It puts the brake on vigorous activity and prepares the body for rest and digestion.  Chapter 3



10. Which of the following is considered strong evidence in favor of heritability?

A. Adopted children resemble their adoptive parents more than their biological parents.

B. Adopted children resemble their biological parents more than their adoptive parents. **

C. Dizygotic twins resemble each other more than monozygotic twins do.

D. Monozygotic twins reared together resemble each other.

78%; .32.  All behavior depends on both heredity and environment, but variations might depend more on the variation in genes or variations in the environment. Heredity is an estimate of the variance within a population that is due to heredity. Heritability ranges from 1, indicating that heredity controls all the variance, to 0, indicating that it controls none of it. The definition of heritability includes the phrase “within a population.”  Chapter 3



11. A neuron fires after receiving 5 units of stimulation from a presynaptic neuron.  What happens if it then receives 10 units of stimulation?

A. It will fire twice as strongly.

B. It will fire at the same strength as it did previously.**   

C. It may fire again during the absolute refractory period.

D. It will not fire again until the relative refractory period is over. 

58%; .44.  Axons convey information by a process called an action potential, an excitation that travels along an axon at a constant strength, no matter far it travels. Information is regenerated without loss of strength at each point along the axon. Thus, it will fire 10 units if it received 10 units from the previous neuron to the next neuron.  Lecture 2



12.  In response to stress, the parasympathetic branch of the autonomic nervous system:

A. has a rapid onset and a slow offset.

B. has a slow onset and a slow offset.**

C. has a slow onset and a rapid offset.

D. has a rapid onset and a rapid offset.

51%, .39.  The sympathetic nervous system predominate during danger and the parasympathetic nervous system predominate during recovery after the danger. Thus, during stress, the parasympathetic system has a slow onset so that the sympathetic nervous system can fully perform its fight or flight response. The parasympathetic nervous then slowly comes on as the danger gradually subside, enabling the need the sympathetic response system to kick in again if required. Lecture 2




13.  Coma and the persistent vegetative state are most likely to result from damage to the:

A. pons (metencephalon)

B. medulla (myelencephalon)

C. reticular formation (mesencephalon)**

D. cerebral cortex (telencephalon)

49%, .45.  The midbrain, comprising the middle portion of the brainstem, includes the reticular formation (from the Latin word reticulum, meaning "net").The reticular formation also is important in regulating cortical arousal. Cats who have suffered surgical destruction of the reticular formation lapse into a constant state of sleep, and can be awakened only by loud noises or other intense stimulation, if at all. Cats whose reticular formation is continually stimulated by implanted microelectrodes remain constantly awake; when the current is turned off, they return to their regular sleep-wake cycle.  Lecture 3



14. In the motor homunculus, the area controlling the mouth, lips and tongue is located:

A. in the parietal lobe, near the cerebral commissure.

B. in the occipital lobe, near the junction with the temporal lobe.

C. in the frontal lobe, near the lateral fissure.**

D. in the temporal lobe, near the fusiform gyrus.

61%, .26.  The motor homunculus (from the Greek, freely translated as "little man in the head") represents the regular association between the location of a particular body part, and the cortical site that controls its motor activity. The legs and feet are controlled by portions of the frontal lobe tucked inside the longitudinal fissure; the trunk and arms and hands along the upper surface of the frontal lobe, along the central fissure; the face is there too, right near the temporal lobe; and the vocal apparatus is tucked inside the lateral fissure. Note that the amount of cortex dedicated to each are of the body is proportional to the need of that body part for precise motor control. There is also a "speech area" in the frontal lobe, adjacent to the motor areas controlling the mouth, tongue, throat, and larynx: more about this later. Similarly, the sensory homunculus represents the regular association between the location of a particular body part, and the cortical site that receives tactile sensations from that body part: the feet are near the legs, adjacent to the longitudinal fissure, the hands are near the arms, adjacent to the central fissure, with the trunk is in between them; the face is near the temporal lobe, near the lateral fissure; and the internal organs are tucked inside the lateral fissure. Again, there is proportional representation, with greater amounts of cortical tissue devoted to those body parts (like the hands and feet) that make fine tactile discriminations.  Lecture 4.



15.  The brain structures important for the central control of attention are locate in the ____ lobe.

A. frontal**

B. parietal

C. occipital

D. temporal

65%, .07.  Research on attention show how different parts of the brain, each performing their own specialized function. According to stage of model of attention proposed by Posner and colleagues, attention is something that involves a sequence of activities. Brain imaging studies showed that alerting function is performed by areas in the frontal lobe. Frontal lobe is also important for executive functions, such as decision making and bypassing current pleasure for future gain.  Lecture 4



16.  A “split-brain” patient cannot:

A. point with his left hand to an object whose name is presented to his left visual field.**

B. point with his right hand to an object whose name is presented to his left visual field.

C. speak the name of an object presented in the center of his visual field.

D. point to an object presented in the center of his visual field.

46%, .31.  Each hemisphere of the brain gets sensory input mostly from the opposite side of the body and controls muscles on the opposite side. Contralateral projection is vividly illustrated by so-called “split-brain” patients. The two hemisphere constantly exchange information. If you feel something with the left hand and something else with the right hand, you can tell whether they are made of the same material because the hemisphere pass information back and forth through the corpus callosum, a set of axons that connect the left and right hemispheres of the cerebral cortex. Specifically, the right hemisphere controls the left side of the body and the left hemisphere controls the right side of the body. Thus, a split-brain patient would not be able to point with his left hand to an object whose name is presented to his left visual field because that area is controlled by his right hemisphere.  Lecture 5



17.  Recovery of function following brain damage, such as a stroke, is most likely a result of:

A. neurogenesis.

B. plasticity in neural organization.**

C. equipotentiality in the late stages of brain development.

D. reverberations across the corpus callosum and anterior commissure.

75%, .16.  When we talk about brain anatomy, it is easy to get the impression that the structures are fixed. In fact, brain structure shows considerable plasticity, that is, change as a result of experience. Early researchers believed that the nervous system produced no new neurons after early infancy. Later researchers found that undifferentiated cells called stem cells develop into new neurons in certain brain areas and not others. New experiences stimulate various axons and dendrites to expand and withdraw their branches. These changes, which occur more rapidly in young people but continue throughout life, enable the brain to adapt to changing circumstances. Lecture 5



18. To say that a theory is falsifiable is to say that

A. it is based on results that are not replicable.

B. investigators have replaced it with a more accurate theory.

C. we can imagine results that would contradict it. **

D. it is so vague that it fits any and all possible results.

84%, .32.  A well-informed theory is falsifiable. That is, stated in such clear, precise terms that we can see what evidence would count against it – if, of course, such evidence existed. Falsifiable does not mean we actually have evidence against a theory. (If we did, it would be falsified). Falsifiable means we can imagine something that would count as evidence against the theory. A theory that makes only vague predictions is not falsifiable.  Chapter 2



19. An operational definition is a definition that

A. explains where the term came from.

B. describes the underlying cause of something.

C. gives synonyms or antonyms.

D. tells us how to produce or measure something. **

79%, .04.  An operational definition is a definition that specifies the operations (or procedures) used to produce or measure something, ordinarily a way to give it a numerical value. A famous (some would say notorious) example is "Intelligence is what intelligence tests measure".  An operational definition is not like a dictionary definition. An operational definition just says how to measure something. It lets us get on with research. Chapter 2



20. Which of the following would be most likely to rely on naturalistic observations?

A. a psychologist studying the effects of reward and punishment on animal behavior

B. a biopsychologist studying the role of various brain structures in memory

C. a cognitive psychologist studying memory for concrete versus abstract words

D. a cross-cultural psychologist studying how people in different cultures settle disputes**

78%, .34.  A naturalistic observation is a careful examination of what happens under more or less natural conditions. Psychologists sometimes try to observe human behavior “as an outsider”. A psychologists might observe how often strangers smile at each other when they pass on a street.  Chapter 2



21. What is the advantage of the experimental method as opposed to correlational studies?

A. An experiment is better suited to studies of unusual individuals.

B. An experiment can consist of as little as one observation of a single individual.

C. An experiment can demonstrate cause-and-effect relationships. **

D. An experiment is easier to do and poses fewer ethical problems.

83%, .23.  To determine causation, an investigator uses an experiment, a study in which the investigator manipulates at least one variable while measuring at least one other variable. The independent variable is the item that an experimenter changes or controls. If the procedure causes different groups to behave differently, you can think of the independent variable as the cause and the dependent variable as the effect. Chapter 2



22. Results of a before-and-after study are often difficult to interpret. Why?

A. Participants in such studies are randomly assigned to groups.

B. Such studies use a falsifiable hypothesis.

C. Such studies lack an operational definition.

D. Such studies lack a control group. **

70%, .31.  Imagine a chemist adding one clear liquid to another. Suddenly the first mixture turns green and explodes. Can we conclude cause and effect? No. Instead of a before and after study, a better design is to compare two groups: An investigator provides the treatment for one group (the experimental group) and not the other (the control group), with participants randomly assigned to the two groups. The difference, if any, that emerges between the groups is an indication of the treatment’s effect. Even then, we should beware of generalizing the results too far.  Chapter 2



23. In the following distribution of scores, the _____ is the most appropriate measure of central tendency.

 1   2   3   3   5   7   7   9   9   9   10

A. mean

B. median**

C. mode

D. standard error of the mean

37%, .18.  A bad item.  When the population distribution is far from symmetrical, as this one seems to be, we can better represent the typical scores by the median instead of the mean. But maybe the skewness was too subtle.  To determine the median, we rearrange the scores in order from the lowest to the highest. The middle score is the median. While the mean is the sum of all the scores divided by the total number of scores.  The standard error of the mean is a measure of variance, not of central tendency.  Lecture 6



24.  In a scatterplot, an “envelope” drawn around the points resembles a fat cigar going from the upper left to the lower right.  The correlation between the two variables is probably:

A. positive and relatively weak.

B. positive and relatively strong.

C. negative and relatively weak.

D. negative and relatively strong.**

52%, .22.  In a scatterplot, the correlation can be estimated by the shape formed by the points. If the correlation is +1.00, the points form a perfectly straight line marching from the lower left to the upper right. If the correlation is -1.00, they form a straight line going from upper left to lower right. In a correlation of 0 (zero), an envelope drawn around the points forms something resembling a circle or a square. If the correlation is nonzero, the envelope forms an oblong, football-like shape. The narrower the oblong, the higher the correlation; and the orientation of the oblong (lower left to upper right or upper left to lower right) indicates the direction of the correlation, positive or negative.  Lecture 6



25. What do modern behaviorists generally believe?

A. All behavior can be described as simple responses to current stimuli.

B. Psychologists should devote their efforts to understanding human thought.

C. Behavior results from a history of experiences as well as current stimuli. **

D. Behavior is best explained in terms of free will.

68%, .30.  Behaviorism, a field of psychology that concentrates on observable, measurable behaviors and not on mental processes. Most researchers in the mid-1900s believed that psychology is the study of behaviors. They had little to say about minds or experiences. The behaviorist approach is still alive and well today, but it no longer dominates experimental psychology as it once did.  Chapter 6



26. A tone is followed by a puff of air to the eyes. After several repetitions, subjects blink their eyes when they hear the tone. The tone is the __________ and blinking is the __________.

A. conditioned stimulus...unconditioned stimulus

B. conditioned stimulus...conditioned response**

C. unconditioned stimulus...unconditioned response

D. conditioned response...unconditioned response

86%, .31.  The acquired response is a conditioned reflex. The term conditioned indicates that it arose from previous conditions, not from genetics. The process by which an organism learns a new association between two stimuli, a neutral stimulus and one that already evokes a reflexive response is known as classical conditioning. The metronome in Pavlov’s study is the conditioned stimulus because a dog’s response to it depends on the preceding conditions. The salivation that follows the metronome is the conditioned response. The conditioned response is whatever response the conditioned stimulus elicits as a result of the condition (training) procedure. At the start, the conditioned stimulus elicits no significant response. After conditioning, it elicits a conditioned response. Chapter 6



27.  Some people have been classically conditioned to blink their eyes when they see a flashing blue light. How could we test them for stimulus generalization?

A. Present the flashing blue light without the puff of air.

B. Present the puff of air without the flashing blue light.

C. Present a flashing green light. **

D. Produce extinction, then wait and test response to the flashing blue light. 

76%, .50.  Other major phenomena of classical conditioning can be observed once the conditioned response has been established. For example, the organism may show generalization of the CR to new test stimuli, other than the original CS, even there have been no acquisition trials on which these new stimuli have been associated with the US. The extent to which generalization occurs is a function of the similarity between the test stimulus and the original CS.  Chapter 6



28.  Suppose we want to find an event that will serve as an effective reinforcer for a given person. According to the disequilibrium principle, we should begin by determining

A. which brain areas are more active than average for this person.

B. which other people this person admires and wants to resemble.

C. how old this person is, and how old are his or her friends.

D. which behaviors the person has recently not had an opportunity to do. **

77%, .42.  According to the disequilibrium principle of reinforcement, anything that prevents an activity produces disequilibrium, and an opportunity to return to equilibrium will be reinforcing. Suppose something kept you away from doing one of your daily activities for the last day or two. An opportunity to do that activity would get you back toward equilibrium. Of course, some activities are more insistent than others. If you have been deprived of oxygen, the opportunity to breathe will be extremely reinforcing. If you have been deprived of reading time or phone time, the reinforcement value will be less.  Chapter 6



29. Skinner punished bar pressing in rats attempting to obtain food by having the bar slap their paws when they pressed it. Based on the results, Skinner concluded that punishment is ineffective in the long run. A more accurate conclusion would be that

A. punishment becomes more effective with the passage of time.

B. punishment is effective in the long run only if it inflicts enough pain.

C. punishment does not weaken a response if no other response is available. **

D. brief punishment is ineffective, but repeated punishment becomes effective.

72%, .26.  In contrast to reinforcer, a punishment decreases the probability of a response. A reinforcer can be either a presentation or a removal. Punishment is most effective when it is quick and predictable. An uncertain or delayed punishment is less effective. Punishments are not always effective. If the threat of punishment were always effective, the crime rate would be zero. A better conclusion would be that punishment does not greatly weaken a response when no other response is available. Skinner’s food deprived rats had no other way to seek food. If someone punished you for breathing, you would continue breathing nevertheless.  Chapter 6



30.  What is unusual about birdsong learning?

A. It occurs rapidly but is also forgotten rapidly.

B. It occurs while the individual makes no response and receives no reinforcement. **

C. It does not begin to occur until a bird reaches reproductive age.

D. It occurs more rapidly in females than in males.

75%, .21.  Song learning is unlike standard examples of classical and operant conditioning. During the sensitive period, the infant bird listens, makes no response, and receives no reinforcement. His only reinforcer is recognizing that he has sung correctly. The male learns his song most readily during a sensitive period early in his first year of life. Similarly, human children learn language most easily when they are young. Chapter 6



31.  Evolution by natural selection:

A. allows individuals to adjust to changing environmental circumstances.

B. applies to body morphology, but not to behavior.

C. allows species to adapt to changes in their environmental niche.**

D. occurs rapidly in response to sudden environmental changes

85%, .00.  Evolution doesn't really have any effect on individuals' characteristics.  Fit ones reproduce, unfit ones don't, but the unfit ones don't change.  Learning is what enables individual orgnisms to adjust to rapid environmental changes.  Lecture 7



32.  The strength of a conditioned response increases most at the _____ of acquisition trials:

A. beginning

B. middle**

C. end

D. none of the above.

36%, .26.  The process by which a conditioned stimulus acquires the power to evoke a conditioned response is known as acquisition. In traditional accounts of conditioning, acquisition of the CR occurs by virtue of the reinforcement of the CS by the subsequent US. The strength of the CR is measured in various ways: The magnitude of the CR (such as the number of drops of saliva or its liquid volume). The magnitude of the CR is typically limited by the magnitude of the UR. The probability that the CR will occur at all (e.g., the likelihood that any amount of salivation will follow presentation of the bell. On the initial acquisition trial, when the CS and the US are paired for the very first time, there is only an unconditioned response to the US; there is no conditioned response to the CS. On later trials, we begin to observe a response that resembles the UR, occurring after presentation of the CS but before presentation of the US. This is the first appearance of the CR. Even later, we may observe the CR immediately after the presentation of the CS, well before the presentation of the US. In fact, almost from the time of Pavlov, there was a debate about the precise shape of the learning curve.  Ebbinghaus thought it was negatively accelerated, and that view stuck for quite a while, until a more thorough analysis came to the conclusion that the learning curve is negatively accelerated, positively accelerated, or not accelerated at all (i.e., there is no change in the rate of learning), depending on where in the learning curve you look.  The most generalized shape of the learning curve is the one depicted in Lecture 8, Slide 7: slow growth at the beginning, rapid growth in the middle, and slow growth at the end.  In some cases, where the subject (human or animal) can capitalize on prior learning, the first part of the curve is foreshortened or eliminated entirely, giving rise to the appearance of negative acceleration.  But there's absolutely no question that, however you look at it, learning increases most in the middle of the acquisition trials.  Lecture 8



33.  Discrimination learning

A. combines acquisition and extinction.**

B. increases the generalization of the conditioned response.

C. reduces spontaneous recovery of an extinguished response.

D. promotes savings in relearning.

44%, .33.  Discriminate is to respond differently to stimuli that predict different outcomes. You discriminate between a bell that signals time for class to start and a different bell that signals a fire alarm. The process that establishes or strengthens a conditioned response is known as acquisition. On the other hand, the decrease of the conditioned response is called extinction. Extinction is not the same as forgetting. In discrimination learning, people become sensitive to cues that enhance a behavior (acquisition, learning to make a behavior) and cues that decreases a behavior (extinction, learning to inhibit it). Lecture 8



34.  Preparedness does not violate which of the following assumptions of the S-R theory of learning.

A. Arbitrariness.

B. Empty organism.

C. Association by contiguity.

D. Association by reinforcement.**

38%, .37.  Traditional stimulus-response theories of learning were based on three assumptions. Association by Contiguity: associations are formed between events that occur close together in space and time. Arbitrariness: By virtue of reinforcement, any stimulus can become associated with any response, so long as the stimulus can be sensed by the organism (a blind rat can't respond to a visual stimulus) and the response is in the organism's repertoire as a voluntary or involuntary action (a rat can't be conditioned to fly). The empty organism: Behavior (remember that the proponents of the S-R theory were mostly behaviorists in the mold of Watson and Skinner) can be understood solely in terms of stimulus inputs to and response outputs from the organism. However, in both classical and instrumental conditioning, learnable associations are not arbitrary. It is not the case that just any CS can be attached to just any CR. Taken together, these results illustrate what Martin E.P. Seligman, Paul Rozin, and James Kalat have called the preparedness principle. By virtue of its evolutionary history, each species comes predisposed to learn certain associations. These associations are called prepared. Other associations are unprepared: it is possible to learn them, but the learning is relatively difficult because it cannot capitalize on evolved predispositions. Still other associations are contraprepared: impossible to learn even under ideal conditions. The species is simply not "built" by evolution to learn them.  Lecture 9



35. Kamin’s “blocking” effect shows that:

A. reinforcement is not necessary for learning to occur.

B. extinction involves the unlearning or forgetting of a conditioned response.

C. conditioning occurs when the unconditioned stimulus surprises the organism.**

D. trace conditioning involves contiguous, but not contingent, stimuli.

53%, .24.  When animals are first conditioned to the noise, and then receive further conditioning trials with the noise/light compound, testing with the light yields no conditioned response. It's as if they never received any pairings of the light and noise at all. Apparently, the prior conditioning to the noise has "blocked" conditioning to the light. the outcome would be different under different conditions. For example, if the light preceded the noise, which in turn preceded the shock, conditioning would accrue to the light as well as the noise: this is because the light predicts the noise which predicts the shock. Similarly, if there was a change in the US, such as its latency or intensity, conditioning would also accrue to the light as well as the noise: this is because the light predicts this change, providing extra information about when it will occur, or how strong it will be. Finally, consider an experiment in which the animal is conditioned to the noise, and then receives trials where the noise/light compound is not followed by shock. Ordinarily, unreinforced presentation of the noise would yield extinction of fear to the noise. But in this case, testing response to the noise alone yields a big conditioned fear response. The noise alone still predicts shock; the light, in combination with the light, noise predicts the absence of shock. Conditioning occurs only when the CS signals a change in the US. Kamin concluded, further that conditioning only occurs when the US surprises the organism. In the presence of a surprising event, the organism then searches the environment for possible predictors of that event. Among these, it will pay attention to the most reliable predictor, which becomes the effective CS. If there is more than one reliable predictor, it will attend to most salient predictor, leading to the phenomena observed in the "overshadowing" experiment. And it will ignore stimuli that lack predictive power, leading to the phenomena observed in the blocking" experiment.  Lecture 9



36. Observational learning:

A. shows that reinforcement is necessary for learning.

B. occurs in both mammalian and non-mammalian species.**

C. occurs in humans and other primates, but not in non-primate species.  

D. enables an infant to recognize words, but not grammatical rules. 

62%, .26.  Monkeys who are born in the wild have fear of snakes. However, monkey who are born and raised in the laboratory do not fear snakes. Therefore, it seems that snake-fear must be acquired through experience. Therefore, Mineka proposed that monkeys acquire their fear of snakes vicariously, from observing the reactions of other monkeys when they encounter snakes. Thus, snake fear is not innate, but a learned part of what might be thought of as "monkey-culture". Similar findings were also demonstrated in young children by Albert Bandura and colleagues (1963).   Lecture 10



37. If you want to see something in detail you focus it on the

A. fovea. **

B. cornea.

C. periphery.

D. iris.

78%, .32.  The cornea, a rigid transparent structure on the surface of the eyeball, always focuses light in the same way. The lens, a flexible structure that varies its thickness, enables the yet to accommodate and adjust its focus on for objects at different distances. When you focus on a distant object, your eye muscles relax and let the lens become thinner and flatter. When you focus on a close object, your eye muscles tighten and make the lens thicker and rounder. The fovea, on the other hand, is the central area of the human retina. It is adapted for detailed vision. Of all retinal areas, the fovea has the greatest density of receptors. Also, more of the cerebral cortex is devoted to analyzing input from the fovea than input from other areas. Chapter 4



38. Cones send their messages to bipolar cells. Exciting a particular bipolar cell in the retina produces a yellow sensation. According to the opponent-process theory, what sensation comes from inhibiting that cell?

A. green

B. red

C. blue**

D. black

82%, .44.  The opponent process theory of color vision holds that neural impulses arising from the rods and cones excite six neural processes (localized in the retina, optic nerve, and lateral geniculate nucleus) which are themselves arranged into three opposing pairs: black/white; red/green and yellow/blue. Each member of the pair serves as an antagonist of the other, so that excitation of one member inhibits the other. Stimulation by short-wavelength light activates the blue element and inhibits the yellow element.  Chapter 4



39. The place principle--hearing a pitch based on which hair cells along the basilar membrane respond to the sound--applies to which type of sound?

A. low frequency sounds (less than 100 Hz)

B. intermediate frequency sounds (100-4000 Hz)

C. high frequency sounds (above 4000 Hz) **

D. any frequency of sound, if the intensity is low

52%, .21.  We hear pitch by different mechanisms at different frequencies. At low frequencies (up to about 100hz), a sound wave through the fluid of the cochlea vibrates all the hair cells, which produce action potentials in synchrony with the sound waves. This is the frequency principle. Beyond about 100Hz, hair cells cannot keep pace. Still, each sound wave excites at least a few hair cells, and groups of them respond to each vibration with an action potential. This is known as the volley principle. At still higher frequencies, we rely on a different mechanism. At each point along the cochlea, the hair cells are tuned resonators that vibrate only for sound waves of a particular frequency. The highest frequency sounds vibrate hair cells near the stirrup end and lower frequency sounds (down to about 100-200 Hz) vibrate hair cells at points farther along the membrane. This is the place principle.  Chapter 4



40. If a stimulus is slightly weaker than the absolute sensory threshold, how often would we expect a person to be able to identify its presence?

A. never

B. never consciously, but almost always at an unconscious level

C. about 75% of the time

D. a little less than half the time**

35%, .29.  Researchers define absolute sensory threshold as the intensity at which a given individual detects a stimulus 50% of the time. In the experiments in which people are presented either no tone or one of various faint tones, people can either report hearing or not hearing something. However, people sometimes report hearing a tone when none was present. When people try to detect weak stimuli, they can be correct in two ways: reporting the presence of a stimulus (a “hit”) and reporting its absence (a “correct rejection”). They can also be wrong in two ways: failing to detect a stimulus (a “miss”) and reporting it present when it was absent (a “false alarm”). Chapter 4



41. One reason why the moon appears larger at the horizon is that

A. we compare the moon at the horizon to the sizes of other objects at the horizon. **

B. eye muscles fatigue more rapidly when we look up than when we look straight ahead.

C. the light is distorted as it passes through the atmosphere.

D. Most eyes are not exactly round.

85%, .36.  To most people, the moon at the horizon appears about 30% larger than it appears when it is higher in the sky. This moon illusion is so convincing that many people have tried to explain it by referring to the bending of light rays by the atmosphere or other physical phenomena. However, if you photograph the moon and measure its image, you will find that it is the same size at the horizon as it is higher in the sky. One explanation is size comparison. When you see the moon low in the sky, it seems large compared to the tiny buildings or trees you see at the horizon. When you misjudge the distance to something, you misjudge its size. Chapter 4



42. Which sensory modality is paired with the wrong projection area?

A. Vision; Occipital lobe

B. Audition; Temporal lobe

C. Pain; Parietal lobe

D. Equilibrium; Frontal lobe**

81%, .38.  Equilibrium or otherwise known as vestibular sense detects the tilt and acceleration of the head, and the orientation of the head with respect to gravity. It plays a key role in posture and balance. Intense vestibular sensations are responsible for motion sickness. The vestibular system, therefore, is important for balance, a characteristic that maps onto the cerebellum. The cerebellum is part of the hindbrain and is important for any behaviors that require aim or timing, such as tapping out a rhythm, judging which of the two visual stimuli is moving faster.  Lecture 11.



43. In the perceptual constancies:

A. the distal stimulus changes and the proximal stimulus remains constant.

B. the distal stimulus and the proximal stimulus both remain constant.

C. the proximal stimulus changes and the distal stimulus remains constant. **

D. the proximal stimulus and the distal stimulus both change.

48%, .20.  The contribution of the perceiver is also revealed by the perceptual constancies. In size constancy, the perceived size of an object is does not change as its distance from the observer changes. In some ways, this is surprising, because the perceived size of an object is a function of the size of its retinal image, and retinal size varies with the distance between the observer and the object of regard. Therefore, as an object moves closer its retinal image gets larger, and as it moves away, its retinal image gets smaller. However, under natural viewing conditions moving objects do not appear to change in size. In the perceptual constancies, the pattern of proximal stimulation changes, but the perception of the distal stimulus remains constant. Therefore, perception is not entirely driven by the stimulus.  Lectures 11 and 15.



44. In reversible figures:

A. the distal stimulus changes and the proximal stimulus remains constant.

B. the distal stimulus and the proximal stimulus both remain constant.**

C. the proximal stimulus changes and the distal stimulus remains constant.

D. the proximal stimulus and the distal stimulus both change.

19%, .23.  In all the reversible figures, the same stimulus can be perceived in at least two quite different ways, "depending on how you look at it". Just as in the perceptual constancies, perception remains constant despite transformations in the stimulus, so in the reversible figures perception varies even though the pattern of proximal stimulation remains constant. Either way, the observer is going beyond the information given in the stimulus. Perception is not driven exclusively by stimulation.  Lectures 11 and 16.



45. Which fact contradicts the trichromatic theory of color vision?

A. Red, Yellow, and Blue are experienced as primary colors.**

B. Color blindness comes in two major forms.

C. Orange can be decomposed into red and green.

D. Some visible colors cannot be produced by color mixing.

33%, .39.  Television, and the computer you're using right now, relies on the RGB system to produce all the millions of colors. Technically, artists and theater lighting designers produce colors by subtractive mixture, while television and computers produce them by additive mixture. All of this gets accounted for in the trichromatic theory of color vision, originally proposed by Thomas Young in 1802 (Young also proposed the wave theory of light, and translated the Rosetta stone) and by Hermann von Helmholtz in 1866 (in his Treatise on Physiological Optics, 1856-1867). The trichromatic theory, also known as the Young-Helmholtz theory, gets its name from the idea that there are three types of cones, each maximally sensitive to one of three primary colors: "red" (sensitive to long wavelengths), "blue" (sensitive to short wavelengths), and "green" (sensitive to medium wavelengths).  Lecture 12.



46. In some animal, an increase of 20 units is required to detect a change from an original stimulus 100 units in strength. How great an increase would be required to detect a change from a stimulus that is 200 units in strength?

A. 10 units.

B. 20 units.

C. 30 units

D. 40 units.**

765, .28.  Just as each neuron has a threshold for firing, so each modality has a threshold for detection -- for conscious awareness of a stimulus event. The absolute threshold is the weakest stimulus that can be detected in a modality. The human sensory apparatus is remarkably sensitive: under optimal circumstances, we can see a candle flame 30 miles away on a dark night; and smell a single drop of perfume in a 6-room house. The relative threshold is the smallest change in intensity that can be detected -- the "just-noticeable difference" (JND) in stimulation. Notice that the absolute threshold is a special case of the relative threshold, as it represents the JND between nothing and something. In psychophysical terms, intensity is related to the amount of stimulus energy falling on the sensory surfaces. The more intense the stimulus, the stronger the sensation. This would seem fairly obvious. But, in fact, there is no isomorphism between physical and sensory intensity. For example, the relative threshold -- the amount of change in physical energy needed before that change is detectable -- depends on the intensity of the original stimulus. If the original intensity is low, even a very small change is noticeable. If it is high, a relatively large change is required.This principle is represented in Weber's Law: In other words, the amount of intensity which must be added to a stimulus to produce a JND is a constant fraction of that intensity.  Lecture 13.



47.  In a signal detection experiment, an observer receives a reward of 35 cents for every hit, and a penalty of 10 cents for every false alarm.  Under these circumstances:

A. The observer’s sensory acuity will increase.

B. The observer’s sensory acuity will decrease.

C. The observer’s response bias will lean toward saying “yes”.**

D. The observer’s response bias will lean toward saying “no”. 

74%, .42.  In a signal detection experiment, people’s responses depend on their willingness to risk misses or false alarms. (When in doubt, you have to risk one or the other.) Under these circumstances, people are going to be more likely to guess yes when in doubt because a correct answer will lead to more reward than penalty. On the other hand, if the rules change: You receive a reward of 10 cents for every hit and 35 cents for every false alarm, now you only say yes when certain.  Lecture 13.



48.  Optic flow is a ____ cue to distance.

A. ocular and binocular

B. ocular and monocular

C. optical and binocular

D. optical and monocular**

39%, .40.  Optic flow also refers to the movement of images across the retina as the observer moves around the environment. If you're a pilot landing an airplane, objects appear to diverge outwards from a convergence point directly in front of you (this follows from the principles of linear perspective). Objects that are close by, like the near end of the runway, diverge very quickly, compared to distant objects, like the far end of the runway. If you're in the rear car of a train looking out the back window, objects appear to converge inwards toward the convergence point. And, again, nearby objects appear to go by quickly, while faraway objects don't appear to move much at all. So, in both cases, the relative velocity of images across the retina is a cue to the relative distance of the objects.  Lecture 14



49.  Feature detectors:

A. illustrate the Gestalt principle of closure.

B. are acquired through experience

C. are examples of “bottom-up”, data-driven processing.**

D. are examples of “top-down”, conceptually driven processing.

55%, .46.  How do we recognize patterns? According to one explanation, we begin by breaking a stimulus into its parts. For example, when we look at a letter of the alphabet, specialized neurons in the visual cortex, called feature detectors, respond to the presence of simple features, such as lines and angles. One neuron might detect the feature “horizontal line”, while another detects a vertical line, and so forth. In a study by Hubel and Wiesel recorded the activity of neurons in the visual cortex. Most neurons responded vigorously only when a portion of the retina saw a bar of light oriented at a particular angle.  Lecture 15



50. Many perceptual illusions:

A. reflect unconscious inferences from knowledge such as the “size-distance rule”.**

B. show that the perceptual system evolved to pick up size and distance cues in the environment.

C. occur only in ambiguous figures.

D. show that contextual surround is not important for perceptual organization.

74%, .22.  According to the ecological view, the perceptual systems have evolved in such a way that we directly perceive the world as it really is. But in the perceptual illusions, we perceive things that aren't there. Relative Size: The size of a retinal image depends on the visual angle subtended by the object. According to the size-distance rule: If the distance from the observer to two objects is constant, the size of their retinal images will be a function of the size of the objects. If the size of two objects is constant, the size of their retinal images will be a function of their distance from the observer. Thus, if two images are of similar shape, but different relative size, there are two possibilities: both are at the same distance from the observer, but one is smaller than the other; both are of the same size, but one is closer than the other.  Lecture 16