The correct answer appears first and is boldface.

1. a. Habituation is a learning process that involves a gradual decline in a response following repeated presentations of a stimulus. Cassy has become habituated to the dog's barking and is no longer startled by it.

b. In classical conditioning, responses come to be elicited more frequently by a neutral stimulus that has been paired with an unconditioned stimulus. The dog's barking no longer elicits a response from Cassy; therefore, it has not become a conditioned stimulus.

c. In operant conditioning, the individual would have to make a response and that response would have to be followed by a reward or the removal of an aversive stimulus to increase in frequency. Cassy's response was initially a reflexive response to the loud noise and was not followed by any consequences that would lead to an increase in her crying responses.

d. Imitation involves the observational learning of a model's behavior. Cassy has not learned to imitate the dog's bark.

2. c. The conditioned stimulus is originally neutral and gets associated with the unconditioned stimulus. Presumably, hearing the song before any conditioning takes place would not have made David cry. At the same time the unconditioned stimulus (the shock) was presented, he heard the song, therefore associating the song with the stimulus.

a. The conditioned response is crying after hearing the song. A response is always a behavior on the part of the person being conditioned.

b The unconditioned response is crying after receiving the shock. This is a. natural, unlearned response.

d. The unconditioned stimulus is the shock. This is an event in the environment that will elicit a response, without any learning taking place.

3. c. The song was a neutral stimulus at one time, but after repeated pairings with the bottle, it has become a conditioned stimulus.

a. This scenario describes a classical conditioning procedure. "Positive reinforcer" is an incorrect answer because it is an operant conditioning term, not a term describing classical conditioning.

b. The unconditioned stimulus is the nipple on the bottle.

d. The conditioned response is the sucking elicited by the conditioned stimulus.

4. b. Operant behaviors are those that, when followed by a desired consequence (a positive reinforcer), increase in frequency. Colin likes to see the mobile move, and therefore he has learned to kick to get this result.

a. In classical conditioning, conditioned and unconditioned stimuli occur before the responses. Colin's behavior does not match the behavior elicited by classical conditioning, since he is making a response to receive stimulation.

c. Imitation is a form of learning that does not require reinforcement. There is no reason to believe that Colin is imitating someone's behavior.

d. Observational learning occurs without reinforcers. There is no reason to believe that Colin learned to kick by observing someone else kicking.

5. d. Older infants and young children may experience illness, teething, or some other discomfort that causes them to have difficulty falling asleep. These problems must be ruled out if the sleep problem is caused by factors other than learned behaviors designed to maintain interactions with caregivers.

a. Active games just prior to bedtime may increase arousal level and expectations of continued exchanges that are difficult to stop.

b. Although brief, gentle rocking prior to bedtime may reduce arousal level and promote sleep, the positive reinforcement from social interactions associated with rocking may encourage the child to make efforts to remain awake for increasingly longer times.

c. Placing the child in the midst of other family members is not likely to promote sleep because of the positive nature of social and other kinds of interactions that may take place.

6. b. Piaget suggested that deferred imitation is one of the behaviors that signifies the emergence of symbolic or representational capacities. The fact that the imitation is deferred, often over a period of days or longer, indicates long-term memory.

a. Habituation, the decline in attention to the repeated occurrence of a stimulus, is already demonstrated in newborns, well before the appearance of deferred imitation.

c. Intermodal perception involves the coordination of information from two or more sensory modalities. Deferred imitation does not depend on this coordination.

d. Social exchanges between young children appear to be strengthened when one child imitates the behavior of another. However, this heightened socialization is probably less likely when the imitation is deferred than when it occurs shortly after the model's behavior.

7. c. Preferential behavior usually is measured by the relative amount of attention given to different stimuli, and habituation involves the decline in attention to a repeatedly observed stimulus and its recovery to a novel stimulus. Operant conditioning is a form of learning.

a. This answer is incorrect because attention is the dependent measure associated with preferential behavior and habituation, and learning is the dependent measure in operant conditioning.

b. Intermodal perception refers to the coordination of information from two or more modalities and is seldom involved in research investigating a single perceptual capacity such as vision. Learning, however, is the dependent measure associated with operant conditioning.

d. Attention, not learning, is the dependent measure when preferential behavior and habituation procedures are involved in testing visual capacities. Intermodal perception refers to the coordination of information from two or more modalities and is seldom involved in research investigating a single perceptual capacity such as vision.

8. b. Benjamin is displaying amblyopia, the failure of both eyes to converge, that is, to turn to focus on where he is looking. This condition, if not corrected, can lead to loss of depth perception.

a. It is possible that Benjamin's visual acuity, particularly in the eye that does not converge appropriately, will be affected by amblyopia. However, his dominant eye, the one that does converge appropriately to view an object, should not suffer from loss of visual acuity as a result of this condition.

c. Color vision is unaffected by amblyopia.

d. Although amblyopia may limit sensorimotor abilities that depend on good depth perception, no evidence exists to suggest that the loss of depth perception interferes with intellectual development.

9. d. The hair or outer contour of the face and head are typically the aspects of a stimulus that a one-month-old is likely to scan; this is referred to as the externality effect.

a. Eyes are an internal component of the face stimulus; infants under two months of age typically do not scan the internal features of a complex stimulus.

b. The mouth is an internal component of the face stimulus; infants under two months of age typically do not scan the internal features of a complex stimulus.

c. The smile is an internal component of the face stimulus; infants under two months of age typically do not scan the internal features of a complex stimulus.

10. c. Infants demonstrate the ability to perceive depth shortly after birth and develop a fear of falling once they begin to crawl; thus, Carlos is not likely to crawl off the bed. However, parents need to be alert since Carlos may not be able to stop crawling in time to avoid falling off the bed.

a. Research indicates that once infants have been crawling for some time, they develop a fear of falling. It is not likely that Carlos will crawl off the edge of the bed because he is capable of perceiving the depth to the floor and is afraid of falling.

b. Carlos is not likely to crawl off the bed because he has developed a fear of falling.

d. Binocular depth perception, or stereopsis, develops during the first six months of life. Carlos, a nine-month-old, has binocular perception and perceives the depth to the floor from the edge of the bed; therefore, he is not likely to crawl off the bed.

11. b. When mothers read The Cat in the Hat to their unborn babies, the babies later preferred to hear them read the familiar passage rather than an unfamiliar one.

a. Studies show that infants can distinguish their mothers' voices from other voices.

c. Infants were able to discriminate between the familiar and unfamiliar passages.

d. Studies show that infants can distinguish their mothers' voices from other voices.

12. d. Researchers have found that infants as young as four to six months of age prefer to listen to normally arranged passages of Mozart. This finding suggests that infants have a preference for musical styles that adults also generally find satisfying.

a. Infants prefer some variations in auditory stimulation and likely would rapidly habituate to a recurrent intermittent tone.

b. Music played in reverse order would likely result in an auditory experience that did not contain cadences and transitions that adults generally prefer to listen to. Thus, we would not expect infants to prefer this music either.

c. Music in which segments are played randomly are likely to contain cadences and transitions that adults generally do not prefer to listen to. Thus, we would not expect infants to prefer this music either.

13. a. Infants between six and twelve months of age have little difficulty distinguishing among the many different phonemes found in languages, even those languages to which they are not exposed.

b. By twelve months of age, infants have begun to lose some of the ability to easily perceive the many different phonemes found in different languages around the world, although those Ephraim has heard expressed in Arabic and Hebrew are still likely to be perceived.

c. By eighteen months of age, infants have lost the ability to easily perceive the many different phonemes found in languages other than the one they are learning to speak.

d. By two years of age, Pablo will be able to easily perceive only those phonemes he repeatedly hears as part of Spanish and Portuguese.

14. d. Newborns typically respond to bitter-tasting substances with a mouth opening and a facial expression that suggests disgust.

a. The receptors for taste are well developed before birth. Bitter-tasting stimuli will yield a disgust reaction in newborns; thus, Karen most likely did not take the medicine without a problem.

b. Infants will suck sweet stimuli vigorously, but not bitter stimuli.

c. Newborns lack the voluntary ability to spit out something in the mouth, even if that stimulus is unpleasant.

15. b. Emerging evidence suggests that certain substances, such as sucrose, given during a potential pain-inducing procedure significantly reduce distress in infants, probably because such substances are effective in eliciting the infant's own pain inhibitors.

a. The brain centers for the detection of pain appear to begin developing even before birth, so experiencing some distress is possible even in very young infants. We have no way to measure whether such distress is lower in neonates than in older infants.

c. The parents face the risk that the less effective procedure will not be successful and therefore the infant will still have to undergo the more distressing procedure.

d. No evidence exists to suggest that infants become habituated to pain. In fact, the opposite seems more likely given that infants who have undergone circumcision without pain-reducing medication appear to become more distressed when receiving immunizations later in development compared to infants who received some pain-reducing medication during this earlier operation.

16. b. Research shows that four-month-olds can discriminate, and prefer to look at, visual displays that are synchronized with the audio soundtrack.

a. Infants are able to discriminate between a synchronized film and a nonsynchronized one.

c. Infants do show a preference for looking at a film with a synchronized soundtrack.

d. Infants are also able to visually select their mothers' film images from their fathers' if the mothers' voices are being played on the soundtrack.

17. b. With repeated experience and inspection of the letters of the alphabet, the child recognizes the regularities and differences among such stimuli.

a. Research on perceptual learning reveals that younger children do not discriminate certain perceptual changes in letterlike stimuli until they have had experience with such stimuli. These early perceptual difficulties are normal and do not necessarily indicate a learning disability.

c. Systematic reinforcements by parents or teachers do not appear to be necessary for the child to distinguish among perceptual events; repeated experience and exposure to these events are all that is necessary for perceptual learning.

d. There is no evidence that Janet has a visual perception deficit; her responses are normal for her age.

18. b. Taking the toy away decreases the occurrence of future behavior, and so is a negative punishment. Negative punishment, a type of operant conditioning, refers to the idea that when a desired stimulus is removed, the behavior will decrease the next time the child is in the situation.

a. Positive punishment would be when a stimulus is added to the environment, and as a result, the behavior decreases in the future.

c. Positive reinforcement occurs when a behavior is followed by a stimulus that then strengthens that behavior. For instance, rewards are often types of positive reinforcers.

d. Negative reinforcement also increases or strengthens the behavior, by removal of an aversive stimulus.

19. d. Newborns respond to odors at a very early age. Research shows that when given the choice of smelling pads that had been worn next to their mother's skin versus another women's skin, newborns preferred the pads worn by their mothers.

a. Although infants' sense of smell may continue to develop as they get older, as described above, newborns can distinguish odors.

b. As described above, infants are very capable of making fine-tuned distinctions with their sense of smell.

c. Not only can infants distinguish such odors, they show a clear preference for their mother's scent, as well as for other pleasant scents, such as vanilla or banana.