Read The Story of Psychology Online
Authors: Morton Hunt
A completely different kind of evidence supporting the limbic-system theory of the emotions was produced in the 1970s by J. E. Steiner, a developmental psychologist. He took pictures of newborn infants to whom, before their first feeding by breast or bottle, he gave water flavored sweet, sour, or bitter. The sweet water caused the babies to lick their lips, the sour water to purse them and wrinkle their noses, and the bitter water to open their mouths and spit or retch. Steiner then did the same with anencephalic newborns (anencephaly is a tragic anomaly in which the fetus develops no brain tissue above the brain stem; the newborn soon dies); they exhibited exactly the same facial expressions and reactions. Simple emotions and their facial expressions thus appear to be generated by the brain stem, although the responses are modified later, in normal children, by higher nervous centers as the children learn what is acceptable emotional behavior in their society.
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In the 1950s Magda Arnold, a Czech-born psychologist at Loyola University in Chicago (one of the few women to attain eminence in psychology before midcentury), and others proposed “arousal theory,” an integrated explanation of both motivation and emotion that held their origin to be the “reticular formation” (a network of neurons connecting the brain stem to the thalamus) and the limbic system.
Arousal theory, supported by research using electrode stimulation of the brain, holds that incoming stimuli “activate” parts of the reticular formation and limbic system, which alert the cortex and ready the creature for action.
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Sounds or smells, for instance, will awaken a sleeping animal; a baby’s whimper will bring its sleeping mother wide awake and on her feet in an instant. Such stimuli as deprivation of water, food, or air, or an increase in sex hormone levels, were also shown by electroencephalograms (EEGs)—brain recordings—to activate the reticular formation and, through it, to increase heart rate and overall activity.
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In sum, the theory envisioned the reticular formation as a regulatory device that, on receiving signals by the senses, turns on both physiological activity and emotional responses.
But as Phil Evans, senior lecturer in psychology at North East London Polytechnic, has ruefully said of arousal theory, “Few concepts in psychology have proven so bothersome and yet so superficially attractive.”
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For although it provides a neural explanation of both motivation and emotion, and makes sense of a wide array of data, it is too general. It presents only one dimension of emotion—the degree of arousal— which leaves unexplained the diversity of the emotions. Also, physiological measures of arousal like heart rate and skin conductance often fail to agree with EEG data and observed levels of activity. Finally, studies of sleep have shown that during periods of rapid eye movement (REM), an animal or human is deeply asleep yet has brain waves indicating high arousal of the reticular formation.
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The arousal theory has not been abandoned, but theorists now say that arousal is not the source of the emotions but a concomitant of them. Nor is it a unidimensional condition; there are different types of arousal— behavioral, ANS, and cortical—each with its own characteristics.
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The higher-level cortical influences on motivation and emotion, in fact, have been in the forefront of research for nearly half a century. A single recent case history will document the broad-ranging role of the frontal cortex—the center of cognitive processes—on emotions. “Elliot,” a man in his early thirties, developed severe and incapacitating headaches, due to a large benign tumor behind his eyes. Surgeons
removed it but could not help removing some of the surrounding frontal lobe tissue. Elliot recovered physically but lost the capacity to make decisions and, most curiously, had no emotional reactions to the many mistakes he began making in his career and personal life. The eminent neurologist Antonio Damasio examined him and reported, “I never saw a tinge of emotion in my many hours of conversation with him: no sadness, no impatience, no frustration with my incessant and repetitious questioning.” When Elliot was shown disturbing pictures such as severely injured bodies, he said he knew the pictures were disturbing and that before the surgery he would have felt disturbed—but now felt nothing.
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Philosophic and religious traditions have held that our emotions and drives originate in our animal or physical side, but modern cognitive psychology, drawing on data of cases like that of Elliot and many other sources of more specific information, finds that many of our emotions and motivations are influenced by, or even originate in, the mind. Let us see the evidence.
Psychologists, in stressing first the somatic and then the thalamic-limbic sources of motivation, were ignoring an everyday truth taken for granted by the average person: human beings and higher-level animals often exhibit emotions and motivations stemming from mental needs, not physiological ones.
Dog owners are well aware of this. They have seen their pet, turned loose in a new or unfamiliar house, immediately explore and sniff around the territory, driven not by hunger or any other somatic need but by a need to know.
Parents are aware of it. They have seen their small child happily push the buttons and pull the levers of a toy cash register or similar toy by the hour, driven by a need to find out how things work.
Everyone knows that after being housebound for a day or two by a storm or a minor illness, one feels a need to get out, look around, and see other places and faces, and after long hours of routine work, a need to do something refreshing to the spirit.
Hull, on a behaviorist basis, and Freud, on a psychodynamic one, held the basic motivation of creatures to be drive reduction, but in the 1960s, as cognition was again becoming the central concern of psychology,
a number of researchers began to consider drive reduction theories seriously incomplete and to conduct experiments showing that more advanced creatures are often motivated by cognitive needs and processes.
We learned earlier of two such experiments. The monkeys that opened a window to watch a toy train and those that undid latches without any reward for doing so were motivated not by a physiological need or arousal of the primitive brain but by a cognitive need, namely, for mental stimulation.
Other experiments conducted in the 1950s and after showed that, contrary to behaviorist theory, rats will learn to behave in ways that are unrewarded—at least not by food, water, or other physical gratifications. In several studies, rats chose a path that led them not to food but into a maze, preferred to take a new path rather than a known one leading to food, learned to take a particular fork of a Y maze or to discriminate white from black for the reward of exploring a checkerboard maze, and learned to press a bar to turn on a light when their cage was dark or to turn it off when their cage was bright.
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Not only were the animals aroused by novelty; they actively sought novel situations in order to arouse themselves. Human beings are especially likely to try to arouse their own minds and feelings. We seek to frighten ourselves by going to horror movies, to stir ourselves up sexually by reading erotic material, to challenge ourselves by playing games against opponents as good as or better than ourselves, and to make our minds work by solving puzzles. One psychologist, Fred Sheffield, persuasively made the case that it is not drive reduction that reinforces human behavior so much as drive
induction;
we seek not so much the completion of the movie, book, or game as the excitement of watching, reading, or playing.
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Such behavior makes sense in terms of evolutionary theory. As the motivation theorist Robert White suggested in 1959, highly developed animals, in order to survive, must learn to deal effectively with their environment. To be curious about novel situations and to be self-arousing is to increase the chance of learning to deal effectively with the environment, and consequently of surviving and reproducing.
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But we do not like or seek as much arousal as possible; we prefer moderate stimulation and dislike what is unduly stressful, extremely frightening, or chaotic.
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This, too, has survival value: we and other creatures function best at intermediate levels of arousal.
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In one of many experiments attesting to this, volunteers were given up to a hundred seconds to
solve each of twenty difficult anagrams for a small cash reward. Their level of motivation was measured by having them rate how attractive they found the goal; those who were moderately motivated solved the most anagrams.
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The principle is familiar to everyone. All those who drive cars, play games requiring physical or mental skill, or work for others know that they do not do their best when bored or sleepy—or when under extreme pressure to do well.
Some of the best evidence that the motivation behind self-arousal and exploratory behavior is the desire to achieve competence and control of the immediate environment comes from Piaget’s and others’ studies of children’s cognitive development through play and schooling. We heard about some of Piaget’s relevant observations earlier, but one more example is apropos here. One day Piaget gave his son Laurent, aged ten months, a piece of bread; Laurent dropped the bread, picked it up, broke off pieces, and let them drop again and again, watching each fall with great interest. The next day, Piaget writes,
he grasps in succession a celluloid swan, a box, and several other small objects, in each case stretching his arm and letting them fall. Sometimes he stretches out his arm vertically, sometimes he holds it obliquely in front of or behind his eyes. When the object falls in a new position (for example on his pillow) he lets it fall two or three times on the same place, as though to study the spatial relation; then he modifies the situation.
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The obvious satisfaction such activities yield comes from finding out how the world works and achieving some degree of control over it. In Robert White’s words:
The child appears to be occupied with the agreeable task of…discovering the effects he can have on the environment and the effects the environment will have on him. To the extent that these results are preserved by learning, they build up an increased competence in dealing with the environment. The child’s play can thus be viewed as serious business, though to him it is merely something that is interesting and fun to do.
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This is true not only during childhood; in adulthood, though to a lesser extent, we are impelled to expand our knowledge of, and competence in dealing with, the world we live in.
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But this does not explain the intense motivation of some human beings to seek answers to questions that have no utilitarian value: the age and size of the universe, for instance, or the means by which bees tell each other where to find honey, or the extent to which human personality is genetically determined. As Daniel Berlyne, a gifted motivation theorist, wrote about the motivating force of curiosity:
Few phenomena have been the subject of more protracted discussion than human knowledge. Yet this discussion has usually paid little attention to the motivation underlying the quest for knowledge… Strangely enough, many of the queries that inspire the most persistent searches for answers and the greatest distress when answers are not forthcoming are of no manifest practical value or urgency. One has only to consider some of the ontological inquiries of metaphysicians or the frenzy of crossword enthusiasts to be convinced of this.
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The desire to learn and understand, said Berlyne, could be accounted for in part by psychoanalytic theory, Gestalt psychology, and reinforcement theory, but a fuller explanation lies in the motivation of curiosity. In Berlyne’s view, there is a subtler need behind curiosity than the desire for practical knowledge. Strange or puzzling situations arouse conflict in us, and it is the drive to reduce the conflict that impels us to seek answers.
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What motivated Einstein to develop his general theory of relativity was not its immense practical consequences but what he called a “passion for comprehension”—specifically, a need to understand why his special theory of relativity was at odds with certain principles of Newtonian physics.
In the 1950s and 1960s, psychologists turned up, along with their new findings about cognitive influences on motivation, a wealth of evidence that the mind, rather than the viscera, thalamus, or limbic system, is often the major source of emotional experiences and their physical symptoms. Some of that evidence:
—For half a century it had been known that when a person guilty of some crime is read a list of words or asked questions, some of which are neutral and others of which relate to the crime, the latter often cause a rise in the suspect’s blood pressure and galvanic skin conductance. In the 1950s and 1960s further research found other telltale
symptoms and improved the technology of lie detection equipment. The premise that the conscious mind influences the emotions—or at least guilty anxiety and its associated physical symptoms—was confirmed.
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—In 1953 Howard S. Becker, a sociologist, studied fifty people who had become marijuana users. He found, among other things, that new users have to be taught to notice and identify what they feel, label the state as “high,” and identify it as pleasant. The physiological feelings of the high acquire their meaning in considerable part from cognitive and social factors.
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—In 1958, in a celebrated experiment, Joseph Brady subjected pairs of monkeys to regular stress in the form of electric shock. One monkey of each pair could postpone the shock for twenty seconds by pressing a lever; the other monkey’s experiences were linked to the first one’s. (He was either not shocked or shocked according to what the first one did or failed to do.) Surprisingly, the monkeys who could avoid the shock developed ulcers, the passive ones did not. Evidently the anticipation and burden placed on the first monkey by the ability to control the shock produced anxiety and its somatic symptoms. Those in the shock-controlling group were soon dubbed “executive monkeys,” their situation being likened to that of human executives working under high pressure and constant anticipation of crisis.
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It was not, however, only anticipation that caused ulcers; it was also the uncertainty about when they had to take action. When a researcher named Jay Weiss repeated Brady’s experiment (with rats instead of monkeys), he added a warning tone that signaled the executive rats (but not the passive ones) to take action. Both groups developed ulcers, but the executive rats, thanks to the security of the warning tone, developed distinctly fewer than the passive rats.
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—In 1960, Eckhard Hess (whom we saw, a while back, imprinting mallard ducklings on a mechanical mother) photographed the eyes of volunteers while they looked at different pictures. The pupils of the men widened when they saw pictures of women, especially pin-ups; the pupils of the women did so when they saw pictures of babies, particularly of one with his mother. The mind, recognizing and evaluating the content of the pictures, sent signals to the limbic system, which then generated both peripheral and central responses, namely, the pupillary widening and a sense of sexual interest.
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