My own brain is to me the most unaccountable of machinery—always buzzing, humming, soaring roaring diving, and then buried in mud. And why? What’s this passion for?
—Virginia Woolf
Through countless adaptational challenges and the process of natural selection, we find ourselves with staggeringly intricate and sophisticated brains: Ferraris—not Fords. Ancient networks have been conserved, expanded, and reorganized, while new networks have emerged and combined to perform increasingly complex functions. In the process, some executive functions remained with earlier evolving networks, and some moved up to frontal and prefrontal regions, while still others were assumed by the mind and the social group.
The control of the vast majority of our bodily and mental functions is on automatic pilot. Under normal circumstances, we pay virtually no attention to breathing, walking, talking, and thousands of other complex processes. We can drive a car safely (and mindlessly) for hours while conversing and listening to music. All of this automaticity allows us to focus our conscious attention on just a small fraction of what is happening at any given moment.
The executive cortical areas in our prefrontal lobes are some of the latest neural systems to evolve and the slowest to develop during childhood and adolescence. In many respects these systems continue to develop throughout life, allowing the potential for increasing perspective, compassion, and wisdom. The executive brain contains the control mechanisms that enable us to attend to a particular activity, filter out distractions, make decisions, and act in an organized and purposeful way. If these functions are carried out successfully, we feel calm and safe enough to turn our attention inward for contemplation, imagination, and self-awareness. These capabilities, in turn, create the possibility for art, religion, philosophy, and other uniquely human endeavors.
Think for a moment of a large corporation with a CEO at the top of its executive hierarchy. Lower level managers, who specialize in particular areas of operation, are employed by the corporation to control thousands of diverse functions. Utilizing multiple lower level executives frees the CEO to monitor market forces, keep an eye on the competition, and plan for the future. Just as a CEO is freed from the everyday concerns of production, building maintenance, and bill paying, the executive areas of the cerebral cortex are freed from attention to basic bodily functions, well-learned motor behavior, and visual-spatial organization. The executive brain participates in more basic functions only in situations that are novel and problematic.
Although the executive areas of the brain are traditionally thought of as being responsible for our rational abilities, they actually combine sensory, motor, memory, and emotional information to shape ideas, plans, and actions. This broader view of executive functioning has been guided, in part, by an increasing appreciation of the contribution of emotion and intuition in decision making (Damasio, 1994). Because so much of brain functioning is unconscious, nonverbal, and hidden from conscious observation, the executive brain is also strongly influenced by nonconscious processes. Psychotherapy calls on the executive brain to update and reorganize the relationship among the conscious and unconscious networks they oversee in the service of mental and physical health.
For the purpose of the present discussion, we will focus primarily on the executive functions of the frontal and prefrontal cortices. What we know about these areas is based on a combination of primate and human research, naturalistic observations, and clinical evidence with human patients. Although the focus here is on the frontal and prefrontal cortices, we will return to the idea of multiple executive regions in a later discussion of the parietal lobes.
The Frontal and Prefrontal Cortices
The highest possible stage in moral culture is when we recognize that we ought to control our thoughts.
—Charles Darwin
The frontal and prefrontal cortices are the prime candidates for behavioral and emotional executive functioning in primates and humans. Their organization and connectivity provide for the integration of cognitive and emotional processing (Fuster, 1997). Because there are no primary sensory areas in the frontal cortex, they are entirely dedicated to the association of information that has already been highly processed in other neural systems throughout the brain (Nauta, 1971). For example, projections from the parietal regions contain integrated visual, motor, and vestibular information, whereas those from the temporal lobe have already combined sensory information with socioemotional appraisal.
Although the human frontal lobes initially evolved to organize complex motor behavior, the expansion of the prefrontal lobes added capacities for planning, strategy, and working memory. Neurons and neural networks within the frontal cortex organize our behavior through time (Fuster, Bonder, & Kroger, 2000) by sustaining a memory for the future (Ingvar, 1985) that keeps in mind the eventual consequences of behaviors about to be performed (Dolan, 1999; Watanabe, 1996). The ability to remember the past and predict the future is essential for survival. Broca’s area, in the left frontal cortex, for example, which controls expressive speech, is located adjacent to the area of the motor cortex dedicated to the lips and tongue. This proximity reflects the coevolution and interdependence of spoken language and fine motor control. Because of the evolutionary links between motor behavior and cognition, some theorists consider cognition to be a derivative of motor behavior (Wilson, 1998). Support for this idea may exist in that much of our symbolic and abstract thinking is organized by the visceral, sensory, and motor metaphors that permeate our language (Johnson, 1987).
As we have seen, networks in both hemispheres feed highly processed sensory-motor information forward to the frontal cortex. Simultaneously, multiple hierarchical networks, which loop up and down through the cortex, limbic system, and brainstem, provide the frontal cortex with somatic and emotional information (Alexander et al., 1986). The convergence of all of these networks within the frontal and prefrontal lobes allows them to synthesize diverse information and coordinate our attention, emotions, and cognition with action.
The prefrontal cortex also participates in constructing ideas about the beliefs, intentions, and perspective of others in a process called theory of mind (Goel, Grafman, Sadato, & Hallett, 1995; Stuss, Gallup, & Alexander, 2001). Damage to the prefrontal cortex in early childhood usually results in deficits in the development of theory of mind, including learning social roles, perspective taking, and empathic abilities (Dolan, 1999). Damage in the same areas later in life can also result in deficits in these abilities, sometimes referred to as pseudopsychopathy (Meyers, Berman, Scheibel, & Hayman, 1992). Because empathy requires conceptual understanding, emotional attunement, and the ability to regulate one’s own affect, damage to any area of the prefrontal cortex may impair different aspects of empathic behavior (Eslinger, 1998). Empathic thinking requires both cognitive flexibility and affect regulation in order to pull back from the environment, put our current needs aside for the moment, and imagine the feelings of others.
The act of murder is the ultimate expression of a lack of empathy. As a group, people who have committed murder demonstrate significantly lower glucose metabolism in both dorsal and orbital portions of the frontal areas. This finding exists in the absence of indications of brain damage or decreased metabolism in other areas of the brain (Raine et al., 1994). Although antisocial behavior is a complex phenomenon, correlations exist between deficits in affect regulation, impulse control, and the inability to relate to the experience of others.
The classic example of damage to the orbitomedial prefrontal cortex (ompfc) is the case of Phineas Gage (Harlow, 1868; Damasio, 1994). Mr. Gage was a young and well-respected New Hampshire railroad foreman who was known for his maturity and “well-balanced” mind. An accident on the job sent an inch-and-a-quarter-wide iron bar up through his head, obliterating much of his ompfc. Although free of any “neurobehavioral” deficits from the accident (such as aphasia, paralysis, or sensory loss), his workmates reported that Gage was “no longer Gage.” After the accident he was unable to control his emotions, sustain goal-oriented behavior, or adhere to social conventions. He went from being a young man with a promising future to an aimless and unsuccessful drifter.
The Cortex and Inhibition
What a man’s mind can create, man’s character can control.
—Thomas A. Edison
When we think of the human cerebral cortex, we may think of the accomplishments of music, art, and culture—products of cortical and especially prefrontal evolution. Although we focus on these visible and impressive products of the human brain, the hidden role of the cortex in inhibiting itself and other brain structures is a vital aspect of the brain’s capabilities. Consider this example: we are born with a broad array of primitive brainstem reflexes conserved from our primate ancestors. One of these is the grasping reflex, which allows us to pick up infants by putting our index fingers in their palms and lifting. For the first few months of life infants can hold their own weight, after which they are no longer able to hold on.
It is believed that this grasping reflex is a holdover from a time when newborn monkeys had to hold onto their mothers’ fur to free the mothers’ hands to traverse branches and gather food. So although this behavior is no longer required for survival by humans, it has been conserved within our genetic blueprint. The only possible role it may play for us is to enhance the experience of bonding between newborn and parent. Many parents are captivated and enthralled by the fact that their infant grasps them and holds on so strongly. Over the first few months of life this reflex gradually diminishes as descending fibers from the cerebral cortex connect with the brainstem regions that trigger them. But why does the cortex make this inhibitory process such an early priority? After all there is so much to learn. The most likely reason is that before the cortical motor areas can begin to shape the dexterity of the hands and fingers, they need to be released from the control of this primitive reflex. In other words, before we can move each of our fingers independently and in coordination with each other, they need to be free from the tendency to act together for a single purpose.
Now fast forward to later in life, when this same child is 60, 70, or 80 years old. Her children notice that she seems forgetful and becomes disorganized from time to time, and wonder if there may be something wrong. The family doctor refers her to a neurologist who performs a series of clinical tests. In one of these tests, the doctor asks her to hold her arms out straight in front of her with her hands open and palms facing down. Extending his arms under hers with his palms up, the doctor slides his fingers under her arms from the elbows up towards her hands. As he reaches her wrists, he curls his fingers slightly and holds them rigid. As the doctor’s fingers slide under the palms and then the fingers he is looking to see if the touch of his hand triggers her fingers to curl inward and grasp his own. If they do, he will try it again after telling her not to grasp his fingers. If it happens again, it is likely that the touch of his hand is triggering the same brainstem grasping reflex that she showed early in life. Why is this clinically significant?
It turns out that the reflexes in the newborn do not dissolve, but rather remain embedded within the brainstem throughout life, and are continually inhibited by descending fibers from the cortex. With diseases like dementia, the neurons in the cortex gradually die off and the cortex becomes increasingly compromised. So what the doctor is looking for are signs of compromise of cortical inhibitory functioning suggestive of a potential stroke, tumor, or the onset of dementia. Early reflexes that reemerge after damage to the brain in adulthood are referred to as cortical release signs (Chugani et al., 1987).
This inhibitory cortical function is not limited to primitive reflexes; it is in play when we are able to keep ourselves from reacting in games of Simon Says when Simon doesn’t say, or hold our tongues in emotional situations where saying something would only make things worse. A major neurobiological component of secure attachment is the building of descending fibers from orbital and medial regions of the prefrontal cortex down to the amygdala and other limbic structures, which allow the child to first use parents as emotional scaffolding for the regulation of fear, and later to be able to regulate her own fear through self-talk, memory of positive outcomes, and proactive problem solving (Ghashghaei, Hilgetag, & Barbas, 2007).
The Prefrontal Cortex
One of the most remarkable aspects of an animal’s behavior is the ability to modify that behavior by learning, an ability that reaches its highest form in human beings.
—Eric Kandel
The prefrontal cortex is generally divided into two divisions; the first consists of the orbital and medial regions (ompfc) and the second comprises the dorsal and lateral areas (dlpfc). Although physically contiguous, the orbitomedial and dorsolateral prefrontal areas differ in their connectivity, neural architecture, biochemistry, and function (Wilson, O’Scalaidhe, & Goldman-Rakic, 1993). Research with primates has demonstrated that although both areas play a role in inhibition and control, the dlpfc is involved when the decision is attentional, and the ompfc when it involves emotional information.
The ompfc, first to evolve and first to develop during childhood, sits at the apex of the limbic system and is richly connected with subcortical networks of learning, memory, and emotion (Barbas, 1995). These connections, and their bias toward the right hemisphere, are associated with the extremes of emotional processing. Like the right and left hemispheres with which they are linked, the ompfc and dlpfc can demonstrate various degrees of integration and dissociation.
TABLE 7.1
Functions of the Prefrontal Lobes
Orbital and Medial Regions
Attachment1
Social cognition2
Thinking about a similar other3
Self-referential mental activity4
Appreciating humor5
Encoding new information6
Sensory-visceral-motor linkage7
Estimating reward value and magnitude8
Sensitivity to future consequences9
Achieving goals10
Stimulus-independent thought11
Inhibitory control in emotional processing12
Decisions based on affective information13
Dorsal and Lateral Regions
Cognitive control14
Directing attention15
Organizing temporal experience16
Organizing working memory17
Organizing episodic memory (right)18
Voluntary suppression of sadness19
Learning motor sequences20
Decisions based on complex information21
Thinking about a dissimilar other22
The integration of emotion and cognition23
The cognitive and emotional intelligences in which they specialize have different developmental timetables and learning contexts. Orbital and medial prefrontal areas begin to organize emotional developmentin the context of interpersonal relationships—from the first moments of life. During the first 18 months of life, the ompfc shares a sensitive period of development with the right hemisphere. Dorsolateral areas exhibit an initial lag and then a growth spurt with the development of language and the exploration of our physical and conceptual worlds.
Our prefrontal cortex has two overarching and interwoven areas of function, the regulation of affect and attachments on the one hand, and the synthesis and coordination of cognitive and motor processes on the other. Although these two tasks seem quite different, each is dependent upon the other. Abstract thinking and problem solving are particularly dependent on adequate emotional regulation, which, in turn, can be accomplished by using rational thought and problem solving. The prefrontal cortex also appears necessary for metacognition—our ability to observe our stream of consciousness, revisit memories, and think about our thinking, which depends upon the integration of affect and cognition.
We can observe an array of functions in which the prefrontal lobes participate by examining the kinds of problems that emerge when they are injured (see Table 7.2). We can also see that different regions of the prefrontal cortex specialize in different functions. With most traumatic brain injuries, like the one suffered by Luis, whom you will soon hear about, all of these areas are negatively impacted. On the other hand, more localized lesions may result in some of these symptoms and not others. Each psychiatric illness, too, has its characteristic profile of cognitive distortions, difficulties with emotional regulation, and deficits of self-awareness and self-monitoring reflective of different patterns of frontal lobe involvement.
Problem solving—which requires emotional regulation, sustained attention, and cognitive flexibility—is a central executive function that can become impaired with frontal compromise. Some patients get stuck in a particular way of thinking (perseveration), while others have difficulty utilizing abstract concepts (concrete thinking). They may have difficulty in remembering the outcome of past behaviors and repeatedly apply the same unsuccessful solutions to new problems. Patients with frontal deficits often have a difficult time monitoring social interactions, such as keeping the listener’s perspective in mind and abiding by social rules.
TABLE 7.2
Manifestations of Prefrontal Compromise
|
Orbital and Medial Regions |
Dorsal and Lateral Regions |
|
Social and Emotional Disinhibition |
Loss of Executive Function |
|
Tactlessness or silly attitude |
Forgetfulness |
|
Decreased social concern |
Distractibility |
|
Sexual exhibitionism and lewd conversation |
Decreased memory for the future |
|
Grandiosity |
Decreased anticipation |
|
Flare with anger and irritability |
Poor planning ability |
|
Restlessness |
Deterioration of work quality |
|
Apathy |
Loss of Abstract Attitude |
|
Decreased attention |
Concreteness |
|
Loss of initiative |
Stimulus bound |
|
Lack of spontaneity |
Loss of aesthetic sense |
|
Indifference |
Perseveration |
|
Depression |
Set stuckness |
Luis
The very essence of instinct is that it’s followed independently of reason.
—Charles Darwin
Luis was in a serious auto accident a few days after his 20th birthday. He and his parents came in to see me after his neurologist suggested they all might benefit from family therapy. At the time of their first appointment, I opened the door to find eight people packed tightly into my small waiting room. As Luis, his parents, and five younger siblings filed into my office, I noticed the scars and indentations across Luis’s forehead and imagined the damage beneath them. I knew from talking with his neurologist that he had sustained severe injuries to his prefrontal cortex and that he had become impulsive, irritable, and occasionally violent. Luis now possessed limited inhibitory capacity, reasoning abilities, and almost no ability to be guided by social expectations.
After we all settled in my office, I turned to the father and asked how I could help him help his family. He immediately became tearful, shook his head slowly from side to side, and rubbed his hands together. “He drives too fast,” he said quietly. “I don’t!” exclaimed Luis. “Except for that one time!” Everyone in the family looked away and appeared embarrassed. It was immediately clear that talking back to his father was part of the problem. Although he had always been somewhat impulsive, his parents claimed that he was far worse than before the accident. I suspected that no matter how impulsive Luis might have been before the accident, this disrespectful behavior was new. This effect of Luis’s accident was apparent just a few seconds into the session.
As the family discussed their situation, I found out that Luis’s parents had moved to the United States from Mexico shortly before his birth, and had adapted well to their new home. Despite their successful acculturation, they remained true to traditional Mexican values of loyalty to the family and respect for elders. In this context, Luis’s reflexive and loud contradiction of his father was a source of shame for everyone except Luis. His injury had damaged the networks that allowed him to monitor and control his own behavior and take into account the expectations of others. A year after the accident he returned to his auto repair job but was unable to focus on his work or get along with coworkers and customers. The descending networks of cortical inhibition had been compromised through the loss of so many prefrontal neurons.
Luis didn’t remember anything about his accident and, in fact, had no memory for the weeks before or after the event. He read the police reports to discover that he had lost control of his car while street racing and crashed into a pole. His injuries were compounded by the fact that he was not wearing a seat belt and had installed a steel steering wheel without an airbag. Was this the foolishness of adolescence or evidence reflecting his lack of judgment prior to the accident? His mother reported that he spent most of his time at home with her, and that his behavior was erratic and sometimes frightening. At times he would cry for no reason, yell at her and the others, and jump in her car and race off. A few times, he went into a rage and threw furniture around the house. He had also made sexual statements and cursed using Jesus’s name during the holidays, upsetting everyone in the family. Family members were confused and torn between their loyalty to Luis and their disgust with his behavior.
Automobile, industrial, and recreational accidents, as well as community and domestic violence, all contribute to the increasing number of people who experience traumatic brain injury. Because the frontal areas are located directly behind the forehead, they are also most likely to be damaged in fights and accidents. Although patients with head injuries come from all walks of life, young males are disproportionately represented. Their youthful impulsivity, risk taking, and lack of judgment, all dependent on prefrontal and frontal lobe functioning, make them more vulnerable to damaging these very regions. The massive reorganization of prefrontal brain areas along with biochemical and hormonal changes during adolescence likely contribute to these dangerous behaviors (Spear, 2000). Many of these young men may have already had frontal deficits or slowed frontal development prior to their accidents, amplifying more typical adolescent risk taking. In this way, frontal injuries often compound preexisting deficits of impulse control and judgment, complicating treatment and recovery.
Treatment with Luis and his family was multifaceted. I began by educating the entire family about the brain and Luis’s particular injuries. The specific information was less important than labeling his behaviors as symptoms of his injury. I targeted in particular his cursing and sexual statements, which were, in their minds, connected to his character and spiritual health. By sharing case studies of others with them, I was able to show that Luis’s symptoms were part of a pattern of pathological disinhibition related to his brain damage and not the result of moral lapses or bad parenting.
More specific interventions included enrolling Luis in an occupational therapy program to help him develop the instrumental and interpersonal skills needed to obtain and maintain employment. As the oldest son, it was important for him and the rest of the family that he be productive and regain a sense of self-worth. One of my goals was to reduce his resistance to taking medication that would help him with his anxiety and depression caused by his changed circumstances. I also worked with Luis and his family to develop skills related to stress reduction and anger management. We turned these exercises into family role-playing games that alleviated tension and allowed everyone to participate in helping Luis.
Over time, Luis was able to apply his knowledge of cars to a part-time job in an auto parts store. His occupational therapist helped him establish routines that allowed him to successfully use the computer. Antidepressants proved helpful with both his mood and irritability, and the role-playing games became woven into the family’s everyday interactions. All of these improvements made the occasional outbursts more tolerable and more easily seen as part of his illness. Luis was so very fortunate to have the unquestioning love and support of a strong and involved family.
The Orbitomedial Prefrontal Cortex
Opinion is ultimately determined by the feelings, and not by the intellect.
—Herbert Spencer
Tucked under and between the lobes of the frontal cortex and sitting directly above the eyes, the ompfc is densely connected to the anterior cingulate, amygdala, and other structures of the basal forebrain (Heimer et al., 2008; Zahm, 2006). These networks are of special interest to psychotherapists because they both generate and regulate emotion and attachment (Kern et al., 2008; Levesque et al., 2004; Rogers et al., 2004; Wager et al., 2008; Walton et al., 2003). The anterior cingulate—involved with attention, reward-based learning, and autonomic arousal—first appeared during evolution in animals demonstrating maternal behavior, nursing, and play (Devinsky, Morrell, & Vogt, 1995; MacLean, 1985; Shima & Tanji, 1998). Consequently, damage to either the ompfc or the anterior cingulate results in deficits of maternal behavior, emotional functioning, and empathy. As described earlier, disorders of emotional control are also seen with damage to these regions, including inappropriate social behavior, impulsiveness, sexual disinhibition, and increased motor activity (Price, Daffner, Stowe, & Mesulam, 1990).
The ompfc is vital for appraisal—interpreting complex social events and linking them with their emotional value via connections to the amygdala and other subcortical structures. A good example of this is the ability of the ompfc to modulate the amygdala’s reaction to fearful faces based on the context in which the faces are presented (Hariri, Bookheimer, & Mazziotta, 2000). So while the amygdala will alert us to the sight of an angry face, the ompfc will include information about additional environmental variables and information based on past learning. If the ompfc recognizes the face as that of a feared predator, the fight-or-flight response will be activated. If the ompfc adds that it is the face of a distressed baby, we may approach the child to find out what is wrong and if there is something we can do to help. Damage to either the amygdala or ompfc at any time during life can result in an inability to organize vital social information in a useful manner, resulting in deficits in communication and connection.
Research has demonstrated that the ompfc also calculates the magnitude of reward or punishment value of our behavior such as approaching another for help and winning or losing money while gambling. Estimating reward value is a joint operation between the ompfc and the amygdala (Dolan, 2007; Gottfried, O’Doherty, & Dolan, 2003). Much of this analysis occurs out of conscious awareness and is commonly called intuition. Those of us who are good at “reading” people or gambling might just be aware of having a feeling about a particular decision. In actuality, basal forebrain and somatosensory areas work together to appraise huge amounts of information that provide us with this feeling about what to do even if it is sometimes contrary to our conscious logic (Damasio, 1994).
The Dorsolateral Prefrontal Cortex
Two things control men’s nature, instinct and experience.
—Blaise Pascal
The dorsal and lateral regions of the prefrontal cortex (dlpfc) integrate information from the senses, the body, and memory to organize and guide behavior. The dlpfc performs a variety of functions, including directing attention, organizing working memory, learning motor sequences, and organizing temporal experience (Fuster, 2004). The dlpfc is the latest developing region of the cortex and continues to mature into the third decade of life. This gradual maturation of neural networks is vital to attention and judgment. It can be tracked by looking at the increasing complexity of school curricula and later through the slow decline of automobile insurance rates from the teens into the 30s. The role of the dlpfc in interacting and coping with the environment is highlighted by the reduced spontaneity and flattened affect seen when they are damaged.
A component of the integration of top-down, cortical, and limbic processing occurs in the communication between the ompfc and the dlpfc. The bias of these regions toward the right and left hemispheres respectively allows them to also support the integration of the left and right cerebral cortices. In addition, the dorsal and lateral areas of the frontal cortex evolved to network with the hippocampus while the medial regions became densely interwoven with the amygdala. Thus, the communication among prefrontal regions provides pathways of integration for the hippocampal and amygdaloid memory systems described earlier.
Emotion and higher cognition can be integrated, i.e., at some point of processing, functional specialization is lost, and emotion and cognition conjointly and equally contribute to the control of thought and behavior. (Gray et al., 2002, p. 4115)
Like a tennis doubles team, the ompfc and the dlpfc depend on one another’s performance for optimal functioning. If the ompfc is not doing an adequate job regulating amygdala activation, heightened levels of autonomic arousal will interfere with dlpfc-directed cognitive processes (Dolcos & McCarthy, 2006). This is why we may have difficulties in comprehending and solving even the most basic problems when we are frightened or distraught. On the other hand, if the dlpfc is not properly processing and managing environmental demands, the resultant anxiety will overtax and eventually disrupt emotional regulation. In essence, both inner and outer worlds need to be balanced and adequately regulated for optimal functioning.
Attention-Deficit/Hyperactivity Disorder
Thinking is the momentary dismissal of irrelevancies.
—Buckminster Fuller
Jimmy, an elfin 8-year-old, was referred to me to assess whether or not he had attention-deficit/hyperactivity disorder (ADHD). Before meeting him, I read notes from his parents, teachers, and soccer coach that described his behavior. All agreed he was more distracted and energetic than other children his age. His coach noted Jimmy’s inability to stay focused on the game; one teacher described him as a bundle of energy; his father wrote, in big letters, “Exhausting!” Jimmy’s restlessness and impulsivity made it difficult for other kids to interact with him, and his mother felt he was becoming isolated as his peers sought calmer company.
I walked into the testing room to find Jimmy’s mother slumped in a chair with her face in her hands. She did not react when I entered the room and I wondered if she might be crying. I scanned the room, looked behind the chair and small sofa, but could not see Jimmy anywhere. Before I could speak, Jimmy shouted, “I’m up here!!” Startled, I looked up and saw him perched on top of a six-foot storage unit. I saw his mother momentarily pick up her head, roll her eyes, and lower it back down into her hands. She wasn’t crying, just overwhelmed. It was clear that while making a diagnosis might not be difficult, getting through the assessment process would require stamina and patience.
Jimmy did have ADHD, with the same symptoms his father had when he was a boy. ADHD does sometimes run in families. Apparently, his father still suffered from many symptoms of distractibility and restlessness that created difficulties in his work and relationships. After many failed career attempts, he found considerable success in real estate. The constant movement and transient relationships utilized his energy and personality, while his choice of a business partner—who excelled at handling the details of his sales—protected him from his deficits in attention. Being a stable husband and father, however, proved more problematic.
The treatment for Jimmy included behavioral therapy to help with his attention and social skills, martial arts classes, and stimulant medications. These and other interventions were designed to boost frontal functioning through biochemical and behavioral interventions (social skills and teaching him to stop and think), and by giving him constructive avenues through which to channel his considerable energy. Individuals like Jimmy who suffer from ADHD are characterized by an inability to sustain attention and inhibit extraneous impulses, thoughts, and behaviors. These individuals can be easily lost in daydreams or be in constant motion. They are also in danger of leaping before they look. In fact, Jimmy had been injured a year earlier when he raced into a neighbor’s backyard and jumped into the pool before noticing it had been drained for repair.
Since Satterfield and Dawson (1971) first pointed to a dysfunction of frontal-limbic circuitry, ADHD has been understood to be a disorder of executive control. The common explanation from psychiatrists to parents is that their children have a lag in frontal lobe development that results in a disinhibition of impulses from lower in the brain and difficulties with tasks which require sustained attention. They are also told that there is a good chance their child will “grow out of it” as the frontal lobes mature. In the meantime, stimulant medications will turbocharge these lagging frontal regions, allowing for more functional behavior. While this is a good anecdotal explanation, the underlying mechanisms and the etiology of ADHD are likely much more complicated.
Functional imaging research comparing ADHD to non-ADHD subjects reveals a variety of patterns of higher and lower levels of activation throughout the brain. And like most psychiatric disorders, ADHD is heterogeneous and emerges from a spectrum of genetic, biological, and interpersonal factors (Sun et al., 2005). It is likely that the explanations of the causes and treatments of the disorder lie within hierarchical networks between the attentional and inhibitory circuitry of the frontal and parietal cortex, and subcortical networks in the striatum and cerebellum that trigger and organize motor behavior. It is unwise, however, to necessarily posit these deficits in the frontal lobe because complex behaviors rely on far-reaching circuitry that can demonstrate similar dysfunctions regardless of where in the network the problems exist (Seidman, Valera & Makris, 2005; Willcutt et al., 2005).
Stimulant medications (such as Ritalin) may be working on the frontal lobes, the striatum (Vaidya et al., 1998), the cerebellum (Anderson et al., 2002), or more systemically by boosting general levels of dopamine and norepinephrine (Arnsten, 2000; Arnsten & Li, 2005). All we can be sure of is that it is rebalancing this hierarchical circuitry in a way that decreases motor agitation while enhancing attention. Because the brain works in interactive networks, the safest working hypothesis at this point is that there is a problem in the hierarchical neural networks that both activate and regulate behavior and attention (Durston et al., 2003; Lee et al., 2005; Rubia et al., 1999).
Think of playing a game of Simon Says. Simon Says tests our abilities to respond to the command while monitoring and inhibiting our behavior based on whether or not Simon says. The winner will be someone with well developed, balanced, and integrated bottom-up networks of motor responses and top-down networks of inhibitory control. When we hear a command in the absence of the words, “Simon says,” we feel our body react and the tension of inhibition as we exert control to stop ourselves. The popularity of this game with small children reflects the development of these systems as well as a way to exercise voluntary control over impulses. When individuals with ADHD engage in tasks similar to Simon Says, they show a lower level of activity in the usual cortical areas dedicated to inhibition and instead rely on a more diffuse and less effective group of neural structures as compensatory mechanisms (Durston et al., 2003; Schulz et al., 2004; Zang et al., 2005).
Children with ADHD have difficulties in organizing their behavior when they are confronted with situations that require them to inhibit motor responses and sustain attention to addressing complex tasks. Thus, they have difficulties in learning, which requires attending to and recalling verbal material, complex problem solving, and planning. They require much more motivation to maintain attention, and so they often excel at video games, which capture their attention and for which their ability to shift attention serves them well.
Our understanding of the brains of individuals with ADHD is still limited, and a variety of findings have emerged from research using various imaging techniques (Bush, Valera, & Seidman, 2005). Table 7.3 lists some of the studies that point to an array of differences between ADHD and non-ADHD individuals using different measurement methods. The best guess at this point is that individuals diagnosed with ADHD likely reflect a number of subgroups with different types of brain involvement. They suffer from a number of different processes reflected in the size, shape, and function of their brains. The usual cortical systems of attentional control and inhibition appear compromised while other networks attempt to compensate. Subcortical structures involved in motor movements are also affected in ways that result in greater but less organized impact on experience and behavior.
TABLE 7.3
Attention-Deficit/Hyperactivity Disorder
Functional Magnetic Resonance Imaging (fMRI)
Decreased Activation In
Parietal attentional systems1
Anterior-mid cingulate cortex2
Supplemental motor area3
Right middle prefrontal cortex4
Right inferior frontal cortex, left sensorimotor cortex and bilateral cerebellum lobes and vermis5
Increased Activation In
Left temporal gyrus6
Basal ganglia, insula, cerebellum7
Right anterior cingulate cortex8
Regional Cerebral Blood Flow (rCBF)
Hypoperfusion or Decreased Activation
White matter regions of the frontal lobes and caudate nuclei9
Hyperperfusion or Increased Activation
Right striatum and somatosensory area10
Brain Morphology
Smaller cerebral and cerebellar volume11
Smaller right prefrontal and caudate volume12
Reduction of left cortical convolutional complexity in boys13
Cortical thinning in adults in right parietal, dorsolateral, and anterior cingulate areas—all involved with attentional control14
Loss of cerebellar volume15
Decreased frontal and cerebellar white matter density16
Lastly, I want to mention a phenomenon I have witnessed repeatedly over the years—children who are diagnosed with ADHD and treated with medication but are better described as using a manic defense to cope with overwhelming anxiety. An assessment of the psychological state of the household—parental relationship, parental psychopathology, emotional context of siblings and extended family, external stressors, and so on, can all go a long way in sorting out a proper diagnosis. Chronic stress negatively impacts frontal lobe functioning and can result in memory impairment, poor impulse control, and deficits of attention (Birnbaum et al., 1999).
Summary
Executive functioning is a complex evolutionary accomplishment that we are still in the process of understanding. Many regions across the prefrontal regions and throughout the cortex contribute to our abilities to focus, organize our thoughts, regulate our emotions, and create the experience of self. Head injury, ADHD, and other psychiatric illnesses provide selective insight into the results of dysregulation or loss of neural networks central to executive processing. As our knowledge of neural networks expands, perhaps we gain a greater understanding of how the mind emerges from the wetware of the brain.