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Grand Central
EARLY BRAIN ANATOMY AND VIOLENCE

“But, I don’t understand,” said Dorothy, in bewilderment. “How was it that you appeared to me as a great Head?”

“That was one of my tricks,” answered Oz. “Step this way, please, and I will tell you all about it.”

He led the way to a small chamber in the rear of the Throne Room, and they all followed him. He pointed to one corner, in which lay the great Head, made out of many thicknesses of paper, and with a carefully painted face.

“This I hung from the ceiling by a wire,” said Oz. “I stood behind the screen and pulled a thread, to make the eyes move and the mouth open.”

—L. FRANK BAUM,
The Wonderful Wizard of Oz

Psychiatric testing shows that he is neither psychopathic or sociopathic. He has a problem controlling his impulses. Sometimes he does things without being able to stop what he is doing. He can know it is very wrong when he starts and still keep doing it or he can know that something he is doing is right and then do it excessively. He constantly seeks attention as if he has been deprived of it. He has social skills that are sufficient to interact with other people but his relationships, for the most part, are superficial. . . . He comes from an extremely chaotic, tense, and abusive home environment which is characterized by harsh and inconsistent discipline. Not surprisingly, given his early home environment, he has significant interpersonal difficulties. This is to be expected. If you don’t know how to act and you are not taught this at home, you will act inappropriately elsewhere. As this pattern of interpersonal difficulties continues, anger or violent behavior may result. To cope with his frightening and unpredictable home environment, Jeffrey learned to think of himself first and others later. . . . He functions within the normal range in his intellectual capacities and outside the normal range in his ability to control some of his impulses. At the time of this evaluation, he showed extreme anxiety and was extremely depressed. He had alcohol and substance abuse problems from a relatively early age. . . . He was introduced to serious drugs before the age of five. This is significant in that many of the drugs he reports ingesting are mood intensifiers that affect the limbic region of the brain.

—TESTIMONY OF FORENSIC PSYCHOLOGIST
FROM JEFFREY’S LEGAL DEFENSE FILE

THE HUMPTY DUMPTY YEARS

Like the Wizard of Oz manipulating the show of sounds and lights for Dorothy, the human brain lies at the seat of control of all human behavior. Until very recently we had limited opportunities to look inside at this mysterious three-pound wizard nestled inside the human skull. Because of ethical considerations the primary research methodologies have historically been limited to studies on animals and the rare human specimens available through autopsy. But with new technologies like the positron-emission tomography (PET) scan and magnetic resonance imaging (MRI), we can now look inside the living human brain with noninvasive techniques that produce graphic images of what is going on. The “wizard,” while becoming less mysterious, is inspiring even more awe as we begin to comprehend the complex machinations that take place to produce even the simplest behaviors.

Seemingly normal at birth, Chelsea was born more than forty years ago in a small coastal town in the Pacific Northwest. But unknown to her parents—and to a host of doctors who by school age evaluated her as retarded—Chelsea was deaf. She was isolated in school, where she was classified as being of low intelligence. It wasn’t until she was thirty-one years old that a neurologist recognized her real disability and had her fitted with a hearing aid. Now Chelsea is an active member of her community. She works in a veterinary clinic. The only problem is that after fifteen years of therapy and with normal intelligence, she still cannot speak intelligibly. Chelsea is living testimony to the lesson that in human brain development, there is a critical period for spoken language. Because her brain was deprived of the sounds she needed to hear at a crucial time, the physical connections necessary for organizing speech in coherent sentences have forever been lost to her. Chelsea will never master normal sentence construction.1

Ryan was born to an unmarried college student who decided that the best future for her baby would be secured by placing him with married parents through adoption. However, the adoption agency, unaware at that time of the importance of earliest attachment, was concerned about Ryan’s irregular heartbeat. A response to anesthesia his mother had received for her cesarean delivery, the arrhythmia disappeared fairly quickly. But since medical assurances were paramount to the agency, it placed Ryan in a private foster home where, without the social worker’s knowledge, the foster mother was taking care of nine other children under age three.

Ryan lay in a crib day after day. He drank cold milk from bottles that were propped to feed him. He heard the sounds of the other children, but he rarely saw an adult face. He was handled infrequently; his diapers went unchanged for most of the day. He developed a full-body rash, a bleeding diaper rash, cradle cap, ear infections in both ears, and, most fearsome, an unwillingness to be held or to look at an adult face. At nine weeks, when Ryan was finally placed in his adoptive home, he would turn away from efforts to engage him, staring instead at a bright light or a shining object. He had gained weight normally and, in spite of his rash, was a handsome, red-haired baby. But he did not want to be touched. If he cried, he preferred to lie on a flat space, where he would comfort himself. Ryan was not autistic. He was twice separated from major caregivers and severely neglected. What his brain had missed was touch, trust, and reciprocal contact with a parent. Now twenty-five years old, Ryan looks normal. He is a college student and works full-time. But he is still somewhat withdrawn, and his relationships with people, while improving each year, are superficial and lack spontaneity. Trust is still precarious for Ryan. Touch is still measured.

Neither Chelsea nor Ryan is a violent individual in spite of early losses. Both were raised in loving homes and environments that were protective and prosocial. But Chelsea and Ryan remind us that there are “critical periods” and sensitive periods for several key aspects of human development, including the ability to trust or to feel connected to other people. While we might like to believe that given sufficient opportunity we can reverse any damage done to children, the research tells us that the effects of some early experiences cannot be undone. Scientists use two terms to describe these specifically timed processes. “Critical periods” is a phrase used to describe a window of time in which a specific part of the brain is open to stimulation, after which it closes forever. In human development, neurobiological researchers have confirmed two functions that develop in such critical periods—vision and spoken language. Both fall into a very specific “use it or lose it” opportunity in early life. “Sensitive periods” is a phrase used primarily by psychologists to describe a less precise period of time when it appears that key functions are strongly affected but may not be lost forever. Examples of these functions include the acquisition of a second language and math and logic development.

The enormous power of human experience in shaping the brain has only been gradually accepted following the pioneering work of Dr. David Hubel and Dr. Torsten Wiesel done nearly forty years ago. The doctors sewed shut one eye of newborn kittens to test the effects of sensory deprivation. When the sewn eyes were opened a few weeks later, they were permanently blinded. But the eyes that had remained open could see better than normal eyes. No amount of visual stimulation following this experience could restore sight in the blind eyes. The same procedures performed in adult cats did not result in this rewiring. The doctors received a Nobel Prize for their landmark finding that sensory experience is essential to teach developing brain cells their jobs and that there is a short and early critical period for connecting the retina to the visual cortex, beyond which the opportunity is forever lost.

Babies born with cataracts have taught us that this dependence on environmental input is also true for humans in the development of vision. Babies with cataracts who did not receive surgery in the earliest months grew up blind because the brain cells that would normally process vision died or were called to work elsewhere. By four months of age, babies totally deprived of vision from birth are blind. Children who grow up alone or in the wild without exposure to language until age ten cannot ever learn to speak. In addition, when a baby is deprived of hearing human voices, the connections that allow brain cells to process sound, and consequently language, can become ineffectual. Instead of the neat columns of cells that are characteristic of normal brain structure, the cells are scrambled. The resulting aberrant formation of the cells that provide the biological underpinnings of speech may cause language disorders and in some cases may result in childhood seizures and epilepsy.2

Capacities acquired during critical periods have been confirmed by new graphic-imaging techniques that actually illustrate the growth of connections between brain cells going on inside the brain at specific sites such as the visual cortex during the critical period. Sensitive periods have been delineated primarily through the longitudinal study of human behavior. Some scientists speculate that growth and changes occurring during sensitive periods involve the integration of several rather than one key system of the developing brain. As knowledge of the human brain and its development becomes more sophisticated, it is possible that scientists will develop techniques to document the neural components of the now much more ephemeral behavioral changes, such as the development of trust, with graphic images of corresponding changes in brain physiology or chemistry.

While the last two decades of brain science have shown that the developing brain retains great “plasticity,” including the ability to offset damages in most areas, there are exceptions. And the exceptions primarily occur with key systems developing in earliest childhood. We used to believe that the brain and its activity were set on course and developed on a path controlled entirely by heritable genetic programming. From this perspective, we believed that the brain like any other organ grew to its genetically predestined size and function uninterrupted from the outside world except by injury or disease or the influence of drugs. A burst of new research in the last decade has shown us conclusively that this is far from reality. To the surprise of no one who has specialized in observing the rapid pace of fetal and newborn development, the new technologies show the rest of us some previously unimaginable truths about human brain growth.

The most amazing result of all has been the portrait that emerges of the brain itself. Far from the preset, isolated, and independently functioning organ pictured in our biology texts of a decade ago, the brain is, in fact, a dynamic organism that is constantly reflecting and adjusting to the environment the individual is experiencing. While genetics do set the broad parameters, actual matter in the brain is built—or not—by sound, sight, smell, touch, and movement from the outside environment. By the eighteenth week of gestation, when the brain is still primitive, the fetus has developed all of the one hundred billion to two hundred billion basic brain cells or neurons that it will ever have in a lifetime. But by birth, connecting structures (dendrites and synapses) between those nerve cells have just started to form. Those connections now depend on the outside environment for completion. Stimulation from the baby’s world actually generates the building of the corresponding systems to process that stimulation in the baby’s brain. Seeing people and objects, for example, generates the building of dendritic and synaptic growth in the visual cortex; hearing sounds builds the auditory cortex; and so forth.

Both the matter of the brain and to some degree the function this matter performs are generated by exposure to stimulation. Because we are each different genetically and because each of our environments is different, no two brains are exactly alike. Babies who are talked to and read to or who are exposed to more than one language are building a different set of connections than those who are receiving primarily large-muscle stimulation—patty-cake, pre-walking games, etc. While there are scientists such as Dr. Frank Kiel of Yale University who believe that the brain comes prewired with some concepts, such as a preference for a human face over inanimate objects, there is general agreement in the scientific community that even before birth the brain is shaped by stimulation from the environment. After birth, development is an interactive process between the baby’s physiology and his or her environment.

The dependence of the human brain on the environment for its growth begins to make sense when one considers the purpose of the brain in all organisms. The primary goal of the brain is to enable the organism to survive. The key to survival and to human dominance on the planet is our ability to adapt to the kind of environment in which we find ourselves. Live video photographs can now show us that both the organic matter and the chemistry of the human brain change in response to our environments to allow us to cope with variables in our worlds. The parts of the brain that grow and the parts that don’t depend on the baby’s experience. Dr. Bruce Perry calls this phenomenon “use-dependent development.”

So the genes provide the blueprints and lay down the basic framework of the brain. But the shaping and finishing within that framework is facilitated by the environment. As Ronald Kotulak said in his Pulitzer Prize–winning series on brain development published in 1993 in the Chicago Tribune:

They work in tandem, with genes providing the building blocks, and the environment acting like an on-the-job foreman, providing instructions for final construction. . . . Sounds, sights, smells, touch—like little carpenters—all can quickly change the architecture of the brain, and sometimes they can turn into vandals. . . . The discovery that the outside world is indeed the brain’s real food is truly intriguing. The brain gobbles up its external environment in bits and chunks through its sensory system: vision, hearing, smell, touch and taste. . . . The digested world is reassembled in the form of trillions of cells that are constantly growing or dying, or becoming stronger or weaker, depending on the richness of the banquet.

Our familiar global measures of children’s systematic development, like head circumference and behavioral milestones such as crawling, walking, and talking, are now validated and enhanced by new graphic, computer-generated techniques that enable us to view precise functions in the developing brain. What we are now able to see is the physiology that accompanies and shapes these behavioral milestones. The newly achieved behaviors in turn catalyze the next round of physiological development. Behavior and neurobiological activity are inextricably linked and are, in a sense, two aspects of the same happening.

Perhaps the greatest advantage of the neurophysiological research is its potential to predict or anticipate corresponding behavioral ­changes. Dr. Harry Chugani of the Children’s Hospital of Michigan uses PET scans to measure the metabolism of glucose by the developing brain. He has learned that high rates of glucose use in regions of the brain correspond with periods of rapid overproduction of synapses and nerve terminals. When glucose metabolism declines, this signals the selective elimination, or “pruning,” of excess connections and marks a decline in developmental plasticity. This pattern of proliferation and pruning is then followed by a period of reorganization, when newly formed connections are integrated into existing systems. Dr. Geraldine Dawson of the University of Washington and Dr. Kurt Fischer of Harvard University describe at least thirteen of these levels or stages of brain development. They believe that one stage builds directly on the last, so that later infancy skills are built on those established in early infancy and so on. More than half of these levels occur in the first twenty-four months of life.3

The implications of this new understanding are both promising and discomforting. While the human baby is born with literally trillions of unprogrammed circuits just waiting to be stimulated into great poetry or science or music, there is the reality that for many key capacities, circuits not used may die. The experiences of a child will determine the circuits connected. In an article published in February 1996 in Newsweek, Sharon Begley, having interviewed several prominent neurobiologists, wrote, “They suggest that, with the right input at the right time, almost anything is possible. But they imply that if you miss the window, you’re playing with a handicap.”

WHEN WHAT YOU SEE IS WHAT YOU GET

Like a tapestry constantly being woven, the brain responds to the world around it. While this adaptability is clearly an evolutionary asset, the brain’s dependence on the environment can also have devastating results. When the stimulation is nonexistent or aberrant, opportunities can be lost or muted. While there presently are only a few known critical periods for the development of key capacities, research is showing that the first thirty-three months is the most profound time of opportunities. Scientists are now measuring and documenting these opportunities—or the lack of them—not just in discernible behavioral differences but also in concrete terms such as brain weight.

In 2004, Dr. William Greenough at the University of Illinois at Champaign-Urbana exposed young rats to enriched environments full of toys, exercise equipment, food, and playmates. On autopsy he found that the enriched rats had 25 percent more connections between brain cells than those rats raised in standard laboratory cages. The brains were actually larger and weighed more. Dr. Craig Ramey at the Virginia Polytechnic Institute found that he could produce similar results with studies done on children. Beginning with babies as young as six weeks of age, he exposed a group of impoverished inner-city children to a daily environment that included learning, toys, playmates, and good nutrition. The enriched children were found to have higher IQs than the control group of children from a similar background. The study also found a lower rate of mental retardation and developmental difficulties in the enriched group.

In an interview with the authors, Ramey stated:

In at least eleven separate studies [comparing high-risk children with those who do not receive intervention], we have data to show that, if you do not intervene before twenty-four months, these children will be seriously developmentally delayed.4 And we have no data to show that we can reverse the majority of these delays.5

In three related studies spanning thirty years of research, Ramey has demonstrated that the timing and targeting of early intervention makes all the difference. Concerned about the lack of sustained gains in follow-up studies on children in Head Start, where gains in IQ tend to fade after about three years, Ramey makes a strong case for beginning earlier, in the first months of life, when the neurological circuits for learning words and sound are being built. He began his Abecedarian project in 1972 as an experiment to test whether mental retardation coming from inadequate environments could be prevented. The interventions included intensive high-quality preschool programs combined with medical and nutritional supports beginning shortly after birth and continuing until children entered kindergarten. The researchers assigned children from 120 impoverished families into one of four groups: intensive early education in a day care center from age four months to eight years; from four months to five years; from five to eight years; and none (control group).

Among these families, all of whom were poor, the researchers discovered that the factors that most placed children at risk of cognitive delays or mental retardation had to do with the parents’ educational histories and their intellectual and language abilities. The single strongest predictor of all is the mother’s tested level of intelligence. In the Abecedarian project, of the control-group children, all of whom had mothers with IQs less than seventy, all but one child emerged in grade school retarded or of borderline intelligence. In the intervention groups, children who, beginning at four months, participated in the program five days a week, fifty weeks a year, all tested within the normal range by age three—an average of twenty points higher than children in the control group. When children did not receive intervention until after age five, 86 percent tested below an IQ of eighty-five. Ramey’s research has conclusively shown that interventions that begin at birth and are provided during the preschool years, but not later, have a measurable impact on children’s development, which is sustained to age fifteen. In a follow-up study with Dr. Frances Campbell, Ramey reported that children who were enrolled early in the Abecedarian project still scored higher in reading and in math by five points at age fifteen than did children who did not receive intervention. Ramey believes that early enrollment in the enriched day care is key to these enduring gains. Children enrolled after the age of five showed no sustained gains in IQ or academic performance. In an interview reported by Ronald Kotulak in his Chicago Tribune brain development series, Ramey stated:

The quality of the environment and the kind of experiences children have may affect brain structure and function so profoundly that they may not be correctable after age five. If we had a comparable level of knowledge with respect to a particular form of cancer or hypertension or some other illness that affected adults, you can be sure we would be in action with great vigor.

Neurobiologists studying how the brain develops give us insight into how Ramey’s observations occur biologically. Dr. Charles Nelson of Harvard Medical School studies how the brain changes from experience. As mentioned earlier dendritic and synaptic nerve connections are overproduced and the brain “prunes” those not properly reinforced by stimulation. Nelson refers to this process of overproduction, selective stimulation, and pruning as an “information capture mechanism.” This learning process allows the organism to shape itself in accordance with the variables consistently occurring in the environment and to specialize its responses accordingly. If the information is distorted, so is the development.

Dr. Greenough explains critical periods—such as that for vision—in terms of Nelson’s information capture mechanisms. The critical period occurs because the cells for capturing certain information are there on a time-limited basis before they are pruned or used elsewhere. ­Greenough postulates that information capture mechanisms may also be set in place neurologically to allow the animal to adapt and incorporate the responses appropriate to specific social environments. He believes that if inappropriate experiences (e.g., abuse) occur or if appropriate experiences do not occur—especially when these are combined with biological factors such as attention-deficit/­hyperactivity disorder—later behavior is likely to reflect this early programmed distortion on a sustained basis. Dr. H. F. Harlow’s classic work with monkeys is one example of the information capture process at work in the arena of social development. Baby monkeys separated from their mothers at birth, nursing from a cloth-covered wire substitute mother, were deprived of mutual emotional exchanges with a live, nursing mother monkey. Although the little monkeys received adequate nutrition, the neurons available for reciprocal social communication were not stimulated. As a result, wire-mothered baby monkeys became agitated and withdrawn and had difficulties relating to other monkeys. This pattern of social incompetence continued throughout their lives.

Building upon the work of Dr. Nelson, Dr. Greenough postulates that the brain not only adapts but also orchestrates a pattern of changes throughout the organism in response to repetitive stimulation. Learning a new athletic skill is an example of this process; a series of changes occur beyond physical conditioning. Greenough’s studies on rats show that when something new is learned, there is a synaptic reorganization of the brain. In the motor cortex, nerve cells begin to form additional connections that encode the general skill. Tissue and blood cells are added, making the whole brain better equipped for new skills. The changes that occur are not limited to the brain; they also affect the spinal column and muscles. The brain adapts to the specific changes by orchestrating a cascading pattern of changes.

The size of a toddler’s vocabulary is a more concrete example of the early developmental opportunities afforded by the information capture process. Dr. Janellen Huttenlocher of the University of Chicago has demonstrated that when socioeconomic factors are equal, babies whose mothers talk to them more have a bigger vocabulary. At twenty months, babies of talkative mothers knew 131 more words than the infants of less talkative mothers. At twenty-four months the difference was 295 words. Regardless of the words used, exposure to the sounds of human speech builds the circuitry in the infant brain that creates the path for more words to be absorbed. Repeated exposure actually builds the physiological capacity. The more words the child hears by age one, the larger the vocabulary at age two.6

The cognitive advantages of early intellectual stimulation carry forward as a child reaches school age. From the earliest months of life, babies who are encouraged by caregivers to take an interest in their environments and to explore their world through vision, touch, and hearing score higher on cognitive and language tests both at preschool and at grade school. Dr. Peter Huttenlocher, also at the University of Chicago, has shown that the power of a brain grows in direct relationship to the number of neurons and the number of connections between the cells it contains. The linkages between neurons (synapses) are the connections that make the brain work. Huttenlocher counted these connections during autopsies and found that a tissue sample the size of the head of a pin from a twenty-eight-week-old fetus contains 124 million connections. A newborn sample has 253 million connections, while a sample from an eight-month-old has 572 million. Connections are the most prolific in the beginning of life and start to slow down in production at the end of the first year, tapering off at 354 million connections per sample at age twelve.7

The fetal stage and the first two years of life are the period of most rapid brain growth. During early development the brain produces many more cells and connections than it can use. Which cells survive and what a brain can or cannot do are determined by what a child learns in the first decade of life. Proceeding cumulatively from the beginning, the opportunity to nurture synaptic growth and retention is at its greatest during this early time. It is at this time that we have the greatest possible potential to directly enhance the quality of brainpower ultimately applied to language or music or social, emotional, math, or logic skills. Yet the educational system in this country begins at age five. The fundamental wiring of the brains of our future workforce occurs—or not—before we are paying attention.

The last decade of brain research has clearly demonstrated that the best time for children to learn a second language is in early grade school, not high school. As we learn about brain systems and their maturation, there is growing evidence that preschool rather than ­higher education ought to be the focus of our most creative educational strategies, including interventions to stem emotional and cognitive disabilities that can undermine learning from the time of birth.

In a television interview on Prime Time Live, Diane Sawyer discussed the subject of critical periods in brain development with Dr. Michael Phelps, who coinvented the brain-imaging technique called the PET scan. Phelps was quoted by Sawyer as saying: “The development years are not just a chance to educate, they’re actually your obligation to form a brain and if you miss these opportunities then, you’ve missed them—forever.” The program concluded with poignant images of caged songbirds while in voice-over Sawyer said: “At Rockefeller University there is a birdcage and it’s quiet. The scientists tell us that they’ve learned that when baby songbirds like these don’t hear a parent singing, when they grow up, they will never learn to sing.”8

FROM THE BOTTOM UP

Anatomically, the brain can be divided into four basic parts: the brain stem, the midbrain, the limbic brain, and the cortex. These parts develop in a hierarchical progression starting with simple and gradually moving to more complex functions. This development begins with the brain stem, which controls the basic and most essential functions necessary to sustain life, including involuntary functions like blood pressure, heart rate, and body temperature. Next to develop is the midbrain, which controls appetite and sleep, among other things. Then comes the limbic brain, which is the seat of emotion and impulse. And, finally, the cortex, where logic, planning, and cognition—the executive functions—take place, is developed. Each of these parts of the brain is responsive to the environment, or use-dependent, according to Dr. Perry, and will be shaped by the individual’s unique experience of his or her surroundings.

When we seek to understand violent behavior from the perspective of brain anatomy, we find some surprising realities. First of all, violent impulses are generated in the lower parts of the brain, particularly the limbic system. Under conditions of extreme threat or rage, when the brain is flooded with stress hormones, the “fight or flight” human is not under the governance of the analytical cortex, the seat of rationality and wisdom. Under those extreme conditions, it is the limbic brain and midbrain that are quickest to respond to mobilize the individual. This biological process is well understood by the army. The constant drill and practice in boot camp to prepare for combat is deliberately directed at the limbic brain. The training of new recruits for war conditions, where instantaneous and precise action is called for, must bypass the analytical and time-consuming cortical functions. Even those of us who have never served in the military have our own experiences with the body’s response to emergency or threat and can recall moments of freezing or running when normal rational thoughts were totally unavailable to us until fear or fury subsided. Dr. Perry succinctly explains that our ability to think before we act is related to the ratio between the excitatory activity of the primitive areas of the brain and the moderating efforts of the cortical or higher areas:

Any factors which increase the activity or reactivity of the brainstem (e.g., chronic stress) or decrease the moderating capacity of the limbic or cortical areas (e.g., neglect) will increase an individual’s aggressiveness, impulsivity, and capacity to display violence.9

This understanding of the stress response system and its impact on brain development has huge implications for working with people with attentional or impulsive disabilities. For children with developmental disabilities or damage (e.g., attention-deficit/hyperactivity disorder or post-traumatic stress disorder), cognitively based therapies may be an exercise in futility. To be effective, interventions need to be directed at the limbic and midbrain levels.

Violent behavior is most likely to occur when a young child’s experiences result in lack of adequate stimulation to the cortex—the system for modulation and control—together with overstimulation of the alarm system. The check-and-balance system in the brain may be thrown off. According to Perry, if those experiences are chronic and occur early enough, a state of hyperarousal or of numbing may become a permanent trait in a child, setting the stage for a host of learning and behavioral problems. This is when we build the blueprint. These months are the time of greatest access and potential—and vulnerability—for creating competent and balanced responses to the stressors all children to one degree or another will face in our society.

ALARM CENTRAL: THE LIMBIC SYSTEM

The limbic system lies wrapped at the center of the protective layers of the cortex. The cortex, with its more advanced rational and uniquely human capacities, sits above the limbic brain ready to edit, adapt, and analyze the impulsive behavior originating from this ancient source of fight-or-flight mobilization. Central to the limbic system is the amygdala, from the Greek word for almond. This structure generates strong emotional signals, acting, according to neurophysiologist Joseph LeDoux, as an “emotional guardian.” LeDoux’s research on the role of the amygdala has clarified how impulsive behavior can occur without rational processing or even awareness. According to LeDoux, under conditions of great emotional excitement, signals from the amygdala may, by design, bypass the neocortex, the rational and strategic part of the brain. This seems to be nature’s insurance in case of a need for immediate action in the face of serious threat. In a description of this process in his book Emotional Intelligence, Daniel Goleman writes: “In the brain’s architecture, the amygdala is poised something like an alarm company where operators stand ready to send out emergency calls to the fire department, police, and a neighbor whenever a home security system signals trouble.”10

When a sight or a sound signals a strong negative or painful association such as Dad’s entry into the bedroom at night followed by sexual violation, the amygdala won’t necessarily wait for analysis by the thoughtful neocortex before, upon again hearing Dad’s footsteps in the room, it floods the brain with neurochemicals for fight or flight. The more the painful connection is experienced, the more quickly the limbic alarm response will be triggered. The entry of any man into the bedroom at any time may come to trigger the response. If stimulated intensely or often enough, this alerting system may not subside. Hypervigilance may be the result, so that the individual becomes extremely sensitive to associated cues—such as the sound of heavy footsteps—that warn of oncoming threat. Dr. Perry believes that this kind of trauma occurring often enough or intensely enough can rob a very young child of the ability to learn normally by pulling circuitry meant for other tasks to monitoring for threatening cues in the environment. Initially, these occurrences induce chronically fearful states of hyperarousal in children. If the child is too young to be able to run or resist, she or he will develop a “surrender” or dissociative response. Neurochemical and hormonal responses enable children to go numb or freeze and remove themselves emotionally. Over time, such states may become integrated as traits in the developing child. These can be difficult neurological patterns to change and may inflict permanent damage depending on the age of the child and the type, intensity, frequency, and duration of the trauma.11

Impairment or injury may also affect the activity of the limbic system. In normal individuals, the emergency response generated by the amygdala is held in check by the neocortical process, specifically the left prefrontal lobe. Goleman refers to the role played by this area of the brain as a “neural thermostat.” Impairment or injury may result in an inability to modulate the signals from the amygdala and related limbic structures. The consequence is highly impulsive behavior, unchecked momentarily by reason. People whose behavior is affected by this neurobiological abnormality are at great risk for school failure, drug abuse, and criminality—not because they lack intelligence, but because they have a limited ability to control their behavior. Strong negative emotions like rage or jealousy can suddenly heat up and overrun the entire system—emotion can overtake rationality.

Researchers, including Dr. Frank Wood of Wake Forest University in Winston-Salem, North Carolina, and Dr. Adrian Raine of the University of Pennsylvania, assert that they can see a characteristic pattern of underactivation of the prefrontal lobe together with excessive activity in the region of the limbic system in the brains of impulsive killers. Emotionally charged memories may be stored in the limbic system and may be restimulated—often years later. The neural alarm system is often imprecise or out of date, and, since it acts without rational (cortical) screening, behavior may appear totally out of context in the present circumstances.

There is a great deal of speculation about the possible causes of this kind of brain abnormality. The hypotheses range from injury to the prefrontal lobes to genetic causes. What we know is that children with early discernible impulse-control problems, such as attention-deficit/hyperactivity disorder (ADHD), are at considerably higher risk of later violent behavior when the problem is left untreated, or is treated only by stimulant medication. Negative outcomes for these children are greatly increased when ADHD is exacerbated by familial or environmental factors such as maternal rejection, child abuse, or the modeling of violent solutions to everyday problems.

THE MIND BODY SYNTHESIZER:
THE ORBITOFRONTAL CORTEX

An area of the brain that is receiving increasing attention in relation to infant development is the orbitofrontal cortex. This part of the brain connects the cortex to the limbic system and is critically involved in the regulation of emotions. Here sensory input of all kinds—vision, hearing, touch, taste, and smell—is connected with our visceral body sensations. This is the area responsible for our “gut reactions” to people and events—our earliest associations between experiences in the outside world and our internal physical responses. Dr. Allan Schore, of the Department of Psychiatry and Biobehavioral Sciences at the UCLA School of Medicine, views the orbitofrontal cortex as the key area involved in both infant attachment and emotional regulation, the failure of which can result in impulsive violence.

The orbitofrontal cortex (so called because it sits just above the orbit of the eyes) is positioned at the undersurface and between the two cerebral hemispheres.12 This area represents a central point of convergence of the cortex and subcortex. Because of its unique anatomical location, it receives both sensory stimulation (vision, touch, sound, smell) from the external social environment and visceral information concerning the body’s internal environment, so that interpersonal experiences can be associated with emotional and motivational states.

According to Schore, all the connections between the cortex and the subcortex are regulated by this particular area. As a result, sensory information from the environment, such as the expression on the mother’s face and the tone of her voice, is associated in the baby’s experience with the physical sensations the baby is simultaneously experiencing, such as intense pleasure and excitement or fear and discomfort. When this goes awry, for example, when a baby “fails to thrive” or fails to gain weight, stops growing, and seems to lose interest in living, this is the area of the brain responsible for the linkages between sensual and emotional deprivation and the physical symptoms that result.

The orbitofrontal areas contain neurons that are especially sensitive to the emotional expressions on the human face, which is a primary source of information sent and received in social situations. The orbitofrontal cortex is particularly expanded in the right hemisphere, which connects deeply into the limbic system, where positive and negative emotions are generated. In fact, this part of the cortex sends direct connections to all the lower limbic areas, including the amygdala. Because it is the only part of the cortex that projects directly to the hypothalamus and autonomic centers deep in the brain stem, the orbitofrontal cortex acts as a central control center over both the sympathetic and the parasympathetic nervous systems, which generate the bodily components of emotional behavior.

Schore points out that the critical period for the development of this system exactly coincides with the time period extensively investigated by attachment researchers. He emphasizes that the maturation of the orbitofrontal system is experience dependent: It is directly influenced by the nature of the attachment relationship. The child’s first relationship, typically with the mother, acts as a template for the imprinting of circuits in the child’s developing, emotion-processing right brain. Schore believes that this is the biological root of the shaping of the individual’s adaptive or maladaptive capacities to enter into all later emotional relationships. If Schore is right, an early relationship with an emotionally attuned primary caregiver who regulates the baby’s physical and emotional states provides a growth-promoting environment for the infant’s developing orbitofrontal cortex. Conversely, early experiences with an emotionally unresponsive or abusive caregiver can inhibit the maturation of this system. Schore concludes that a negative early relationship can lead to a lifelong limited ability, especially under stress, to regulate the intensity, frequency, and duration of primitive negative states such as rage, terror, and shame. Schore states:

There is now evidence that the orbitofrontal areas show a preferential vulnerability to a spectrum of later-forming psychiatric disorders, including sociopathic and character disorders that display antisocial behaviors and problems with impulse control.13

We did not understand the significance of the orbitofrontal cortex until the 1940s, when lobotomies were performed experimentally for a time to control extremely emotional individuals. A lobotomy essentially amounts to the disconnection of the orbitofrontal area and results in the total loss of emotionality. While intelligence is unaffected by a lobotomy, the individual loses his or her “personality”—and the ability to relate emotionally. Normal emotional responses are flattened or absent.

This area of the brain was highlighted in studies of Vietnam veterans who suffer from post-traumatic stress disorder (PTSD). Dr. J. Douglas Bremner, a psychiatrist at Emory University, showed slides of Vietnam battle scenes to two groups of veterans, one group of whom suffered from PTSD and one of whom did not. Computerized X-rays (PET scans) that measure the rate of glucose metabolized in different areas of the brain were used to indicate which parts of the brain were functioning during the viewing of the slides. By contrast to those with PTSD, the orbitofrontal area in nontraumatized veterans was highly active, enabling them to distinguish “real” from reenacted scenes. Dr. Bremner explained this process in an article by Malcolm Gladwell published in the New Yorker.

The orbitofrontal region is the part of your brain that evaluates the primal feelings of fear and anxiety which come up from the brain’s deeper recesses. It’s the part that tells you that you’re in a hospital watching a slide show of the Vietnam War, not in Vietnam living through the real thing. The vets with PTSD weren’t using that part of their brain. That’s why every time a truck backfires or they see a war picture in a major magazine they are forced to relive their wartime experiences: they can’t tell the difference.14

GONE BUT NOT FORGOTTEN:
THE AMYGDALA AND MEMORY

Since babies have neither language nor reason and since most of us have no conscious memories of our lives before age two, it would seem to make sense that this time has little influence on our present functioning. This is the logic we have traditionally used to dismiss the role of our earliest experiences. But neuroscientist Dr. Joseph LeDoux points out that the amygdala, together with the hippocampus in the limbic brain, may explain what analysts have been telling us for years: that the events in early life, particularly those experienced with strong emotion, can and do remain an influence throughout our lives. Memory, as it turns out, is not just a matter of rational or even verbal recall. We also have a nonverbal, essentially emotional memory, particularly for experiences, events, and people that carry a strong emotional valence.

Sensual experience (auditory, visual, tactile, and olfactory) typically travels first to the neocortex for analysis. But when perceptions are accompanied by strong emotional impact, particularly those perceived as life threatening, they may bypass the neocortex and send a message directly to the amygdala, which mobilizes the organism for fight or flight. All of this can happen in an instant—and without input from rational processing by the neocortex.

Studies done by Dr. LeDoux in 1989 that exposed rats to fear-inducing visual stimuli provide strong evidence that the amygdala matures very early in life, so that emotional messages can be processed before cognition. In addition, LeDoux found that these fear-based associations experienced early were difficult to erase, even when the sensory cortex was later completely severed. According to LeDoux, early experienced precognitive emotions continue to play out in later life even though the individual may have no conscious memory of the association.15

Dr. George Engel documented this process at work in a thirty-year longitudinal study of “Monica.”16 Monica was a child born with congenital atresia of the esophagus, a condition that precluded her being fed by mouth. For the first two days after birth she choked and regurgitated her feedings. On the third day a feeding tube was inserted into her stomach. For two years she was fed through the tube while lying flat on her back without holding or contact of any kind. She was in fact frequently fed “while crying, fussing or playing” and did not participate in the process. A tube placed in her neck to continuously drain the saliva limited how Monica could be held. Her mother subsequently became depressed and withdrew from her baby. Monica became unresponsive and for a while showed a failure to thrive.

At age two, Monica was hospitalized for nine months while her esophagus was reconstructed. She began to receive oral feedings either lying flat on her back or propped in her crib. Her mother and the nurses still rarely held her. After she returned home, she was able to eat normally. She grew up with no conscious memories of her early tube feedings; she was told by her mother much later that she had been fed by a tube in her abdomen as a baby.

Engel and his associates continued to observe Monica as she grew. As a little girl she fed her dolls in the exact position she herself had experienced, flat on their backs without holding or contact of any kind. Engel also noted that her conversations with the dolls indicated preconscious memories of her earlier experiences. She would place the dolls down on the bed and stand at their side. At four years of age she said to one, “Poor baby, you ain’t got a mouth.” She also talked about the dolls “leaking at the neck,” where she herself had experienced the early drainage tube.

When Monica babysat as a teenager, she fed her charges in the same strange way. When she had children of her own, in spite of having observed her mother feeding her younger siblings normally, Monica seldom, if ever, held their bottles during their feedings. Her mother, husband, and a sister all coached her to hold her babies enfolded in a face-to-face position. Although she was generally compliant with requests from others, she consistently refused close body or face-to-face contact with her babies while feeding them. Instead, clearly acting from early and enduring preverbal memory, she lay them flat across her lap and replicated her own experience.

Infant memory is the subject of much current research at several universities, including the University of Massachusetts. Drs. Rachel Clifton and Nancy Myers, both psychologists, have successfully documented the capacity of two-and-a-half-year-old children to exhibit learning they experienced at age six months.17 Originally researching motor and hearing skills, Dr. Clifton placed sixteen six-month-old babies in a pitch-dark room with objects that made different sounds and used infrared cameras to capture how and when infants reached for the objects. After the initial experience, the stimuli were not repeated until follow-up testing two years later. At that time, the original children were paired with a control group of thirty-month-old toddlers who had not had the original experience. “All of the children were again placed in a dark room with the same objects making the same sounds. The children who had the prior experience reached for the objects without signs of fear.” Fewer of the control group reached for the objects, and many cried. Clifton and Myers believe that the babies, when put into a situation similar to their earlier experience, were able to access memories of a time when they were six months old and the task appeared less frightening.

A growing number of scientists believe that the limbic memory does not wait until birth to begin. Dr. David Chamberlain, a psychologist who was one of the founders of the Association for Prenatal and Perinatal Psychology and Health, finds increasing evidence of a primitive memory stored at the sensory level beginning during late gestation. Chamberlain refers to these memories as “cellular” because they are unconscious and preverbal and are often held and expressed in specific parts of the body.18

Dr. Lenore Terr, a child psychiatrist at the University of California Medical Center in San Francisco, studied children under the age of five who had experienced serious trauma from birth to thirty-four months. Verifiable proof of the trauma the children experienced was recorded in photos, police reports, statements from eyewitnesses, confessions, or corroborating injuries. This is presumed to be a time when little or no verbal memory exists. Yet these children clearly showed that they had retained behavioral memories of their trauma, which Terr found to be reenacted in part or in entirety in their play. Terr believes that traumatic events—especially those experienced early—create “burned-in” images that last a lifetime.

PEASE PORRIDGE HOT, PEASE PORRIDGE COLD

It was only a game. Even though it was for science—it was only a game. The first person who hit the button after the light flashed got to zap his partner with an electric current. The winner could pick a charge ranging from one, a light twinge, to eight, a jolt of pain. These were college students at McGill University in Montreal. They usually picked low dosages of electricity, giving what they got, exchanging only the level of pain they received. That was before the drink. Scientists deliberately raised the aggression level of participants by giving them a dose of amino acids that lowered their levels of the brain chemical serotonin. Soon the game changed. Volunteers began zapping their partners with higher and higher numbers in spite of receiving lower charges themselves. Next, the students were given another snack, this time a dose of tryptophan, an essential ingredient for the brain to produce serotonin. As the serotonin levels rose, the choice of painful jolts diminished. An Orwellian experiment, perhaps, but proof positive that the manipulation of neurochemicals can alter levels of aggression.19

Serotonin-reducing chemicals such as certain amino acids lower the threshold for aggressive tendencies. In rodents, serotonin-reducing drugs were first viewed as aphrodisiacs because the rats became very sexually active under their influence. But aggression soon followed. Handlers were bitten and other rats were attacked just for coming close—behaviors previously unseen in the animals.20

The role of the neurotransmitter serotonin in aggressive behavior has been under study since the mid-1970s when Marie Asberg, at the Karolinska Institute in Stockholm, observed the linkage between low serotonin and violent suicides—suicides involving guns, knives, ropes, or jumping from high places. Criminals with a history of violence were discovered to also have low levels of serotonin. But the effect of serotonin can only be understood in relation to a counterbalancing neurotransmitter, noradrenaline.

While serotonin is known to be key to modulating impulsive behaviors at the neocortical level of the brain, noradrenaline is the alarm hormone designed to alert the system to respond to danger. Together they have a teeter-totter type of relationship: In normal people, serotonin is higher during sleep and decreases during wakefulness, while noradrenaline is higher during wakefulness and lower during sleep. The balance between the two is the key to normal function. For most of us, there is a balance, enabling us to react in reasonable ways. But, as with the McGill students, our functional levels can be altered, at least temporarily. Alcohol and extremely stressful environments can have similar effects to the students’ initial drink of amino acids. When these exposures occur to a developing fetus or infant, the levels of serotonin and noradrenaline are just being built, shaping lifetime patterns.

Violent behavior is roughly of two types: impulsive and premeditated. Most acts of violence are impulsive. “Cold-blooded” or premeditated acts are far less common and are typically enacted by a very different personality than the “hot-blooded” crime. When environmental experiences early in life cause noradrenaline levels to be too high and serotonin levels too low, the result, in the presence of later emotional triggers, may be impulsive violence. Conversely, very low levels of noradrenaline together with low levels of serotonin result in underarousal, which may generate an appetite for high-risk behaviors to achieve arousal, setting the stage for predatory violence or premeditated crimes. Interestingly, very high levels of serotonin are not a means of counteracting this effect. Excessively high serotonin levels result not in well-being, but in rigidity or obsessive-compulsive behavior, like Lady Macbeth’s repetitive hand washing. The balance of neurochemicals in either scenario is thought to be set primarily by early experience.21 When babies develop in an atmosphere of terror or trauma, these neurochemicals can be called upon to enable them to survive. But that which enables survival may also create permanent and lethal imbalances.

Low levels of serotonin may be the result of a genetic error. A single gene inherited by some people from their fathers results in an inability to adequately convert tryptophan from common foods into serotonin. The individual inheriting this gene may have no problem unless there is an additional stressor, primarily alcohol. In affected individuals, alcohol briefly raises, then drastically lowers, serotonin levels. At the latter point, the individual is prone to acting out aggressively. This gene is common—affecting 40 percent of the Swedish population tested at random.22 With 48 percent of the homicides in the United States committed under the influence of alcohol, the role of this interaction is clearly of concern.

Normal serotonin and noradrenaline levels are extremely important to balanced functioning. Without realizing it, our culture is creating more and more individuals with an imbalance in this delicate equation in the brain. Alcohol, drugs, and other toxic exposures such as lead are being implicated in damage to the genes responsible for these neurochemicals. So are conditions after birth such as abusive, terrifying, or war-torn environments, in which impulsive or reactive behaviors are essential to survival. Researchers suspect that conditions of child neglect, child abuse, gang warfare, and domestic violence are—without our awareness—biologically, as well as socially, feeding the cycle of violent crime. As Ron Kotulak stated in his series on the brain:

Underlying the scientific quest, which has revealed genetic and environmental links to abnormal brain chemistry, is the growing suspicion that society may unwittingly be feeding the nation’s epidemic of murder, rape and other criminal acts by making childhood more dangerous than ever.23

Abuse and neglect in the first years of life have a particularly pervasive impact. Prenatal development and the first two years are the time when the genetic, organic, and neurochemical foundations for impulse control are being created. It is also the time when the capacities for rational thinking and sensitivity to other people are being rooted—or not—in the child’s personality.

POSTSCRIPT

We now know far more about how each part of the brain works and about how and when certain capacities develop. In Scared Sick, we report that when trauma occurs very early in life—before the child has learned language—the memory of trauma will be recorded not as a word-based or rationally comprehended event (which is dependent on more maturation of the cortex), but rather as a somatic or “feeling” memory in the limbic brain. Very early experiences of trauma can be very hard to access through words later, even with therapists’ help. Such experiences are now recognized as being at the root of many behavioral problems including addiction. If one thinks about what might motivate one to want not to feel—to be numb or “stoned” or “high”—or otherwise removed from reality, those of us with visceral memories of deep emotional pain may be the most motivated to seek escape from a memory so deeply held and so formative in our worldview.