The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning (45 page)

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Authors: Daniel Bor

BOOK: The Ravenous Brain: How the New Science of Consciousness Explains Our Insatiable Search for Meaning
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The hope is that this multipronged attack will soon lead to a more tailored, neuroscience-based diagnosis to psychiatric syndromes, as well as a clearer idea of which existing drugs will help and which will not. And, ultimately, this should lead to better clues about the novel drugs we should be developing to target the root neurochemical causes of these problems.
BUILDING THE CONSCIOUSNESS MUSCLE
 
Clearly, the current suite of drugs used to treat many psychiatric conditions is not ideal, both in terms of efficacy and side effects. A far safer option, and one well worth trying, given the issues surrounding medication, would be to use behavioral treatment of some form, if it were effective. And if low working memory is a central cause of psychiatric symptoms in certain patient groups, such as those with ADHD or schizophrenia, then some therapy that targeted this problem may really help lift consciousness, giving these patients both the chance to process the world more appropriately and gain better control over their thoughts and behavior.
“Brain training,” currently highly fashionable, might be one route to improving working memory. The kind of popular brain training that is played on game devices has recently, justifiably, received a bad press: Healthy nonelderly people don’t gain any generalized improvement from practicing such games.
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But more clinical forms of brain training, designed specifically to boost working memory function, have shown much promise in alleviating mental illness.
For instance, Torkel Klingberg and colleagues gave ADHD children a battery of working memory tasks to practice for three weeks. They found the children experienced improvements not only in working memory and IQ levels but also in ADHD symptoms. Similar training in the scanner has been shown to boost prefrontal parietal network activity.
When pitted against medication, brain training yields even more interesting results: Joni Holmes and colleagues compared the ADHD working memory improvements due to Ritalin and due to working memory training. Quite surprisingly, there were far more dramatic and widespread working memory gains after training compared with medication—and these persisted for at least six months following the training regime. So for ADHD children, cognitive training may be a powerful route to boosting consciousness and control, all via working memory gains.
Amazingly, cognitive training even works on schizophrenia, the other psychiatric illness closely linked with profound working memory impairments. Melissa Fisher and colleagues used a commercially available cognitive-training program provided by Posit-Science, a San Francisco company, to apply intensive practice in working memory tasks, in this case for at least 50 hours. The schizophrenic patients improved both their cognitive skills, and their ability to function in day-to-day activities, with greater training improvements related to a better ability to cope with life. These improvements were also still present six months after training.
On the one hand, it seems quite surprising that simple working memory practice can alleviate some of the symptoms of these serious psychiatric illnesses. On the other hand, it makes sense that opening up a wider expanse of awareness would lead to an easier avoidance of false patterns and a host of improvements in control, information processing, and strategizing around problems.
A SEESAW OF STRESS VERSUS CONSCIOUSNESS
 
Although ADHD and schizophrenia are characterized by a lower-than-average working memory, certainly not all mental illnesses show this deficit as a central, continuous feature—even if a temporarily reduced conscious capacity in acute episodes does partially explain many conditions. In fact, a label of reduced mental attributes doesn’t even apply to all schizophrenics: Although the majority of schizophrenic patients, before the illness takes hold, already have an impoverished intellect and low working memory, there seems to be a pocket of patients at the opposite end of the spectrum—those who are highly intelligent, and, for a time, tremendously productive.
One of the most famous examples is John Nash, a Nobel laureate in economics, whose story was brought to life by Sylvia Nasar’s book
A Beautiful Mind
, which also became a Hollywood blockbuster movie. Just as Nash was trying to cement his academic career, his prodigious intellect started to unravel. Instead of continuing to use mathematics to unlock a wide range of subjects in a brilliant manner, his focus shifted to outlandish conspiracies; grandiose, utterly unattainable plans; and a host of paranoid delusions.
He started to spot bizarre patterns, coming to believe, for example, that anyone wearing a red tie was a member of a “crypto-communist party.” He would write frantic notes to colleagues complaining that aliens from outer space were ruining his career. He also sent letters to all the embassies in Washington, D.C., declaring that he was forming a world government and wanted to discuss the matter with them. It was his plan to become emperor of the Antarctic. Although he continued to believe his work was of the highest caliber, the ideas were by this stage nonsensical, and soon the illness took full hold and his mind was ravaged by insanity.
During the time leading up to his first schizophrenic episode, Nash was mentally exhausted and probably chronically stressed from the combination of his teaching duties and his stupendously abstruse mathematical research. His wife was also about to give birth.
Nash’s case raises the possibility that it is this very propensity to obsess over deeply challenging mental problems that contributes to mental imbalance in this small pocket of previously mentally superior individuals. Those like Nash are particularly skilled at searching for structure in the world and highly predisposed to devoting hours, days, and weeks to solid concentration on a single topic—which in itself probably places a great strain on their usually highly able prefrontal parietal network. Once the cancerous strands of this imbalance take hold, their conscious machinery can then, far more readily than most, become an internal enemy as it generates intricate paranoid delusional theories, which ramps up the stresses exponentially.
It’s well known that stress is the single biggest trigger for almost all mental illnesses. As Nash’s tragic life demonstrates, it can mangle the most able mind and plunge a person into years of nightmarish suffering. So in order to understand mental illness more generally, we need to understand how stress arises and what effects it has on our awareness and cortex.
If we’re seriously under threat and our lives are in danger—for instance a car, out of control, is headed straight for us—then there is a tension about how best to respond. On the one hand, action is the key—we want to make a decision as fast as possible to move in order to get out of the way. On the other hand, we don’t necessarily want to make too rash a decision to act, as we may run straight into the path of another car, or fail to realize that there’s a concrete reinforced barrier we could hop over and protect ourselves with. This tension is reflected in our emotions and thoughts. First comes our primitive fear, which floods our body with chemicals in readiness for movement and orients us to the danger. The amygdala, our fear center, tends to suppress prefrontal cortex activity so that we don’t think too much, and we act swiftly in whatever automatic way will keep us alive. On the other hand, the prefrontal parietal network can make a slower, more sophisticated, deliberative, conscious assessment of the situation—say, by noticing that although we appear to be in danger, the car moving straight for us is an illusion created by the movie projector on the cinema screen—and we are quite safe. So the half-strangled prefrontal cortex can, in turn, suppress amygdala activity, along with our feeling of fear, and bounce back to retain full conscious control of our movements.
In humans, in real life, the amygdala wins the battle all too often, and for entirely unnecessary reasons. If we were living, as our ancestors did, in a particularly threatening world, where big cats commonly stalked us, cantankerous rhinos and elephants regularly charged us, aggressive snakes liked to bite us, other members of the tribe sometimes wanted to fight us, and competing tribes sometimes declared war on us, then it arguably would be rather useful to be prone to surges of fear. However, it’s not entirely clear that a chronically fearful life, even for our hominid ancestors, would have been beneficial, except in the most unusual, extreme times.
The simple fact is that, in the vast majority of cases, conscious understanding and innovation is a superior tool to instinctive fear. Every one of us faces potentially mortal threats every day. Walking down the stairs could kill us, as could crossing the road. But we learn over our developing years to give such events respect, and we maintain simple routines so that the events seem safe. This is in stark contrast to those animals with less intellect, such as cats, which probably have a burst of terror whenever they cross a busy road.
Most people, especially in the developed world, live safer lives than ever before. But we still carry within us this evolutionary legacy, this primitive machinery of fear, which all too easily latches onto any target we consciously deem important, regardless of whether it is a threat to our lives. So we may be intensely nervous when having to give a public speech, or when playing in a sports tournament. With our prefrontal parietal network shut down by our anxious amygdala, we might be keenly aware of the object of our fear, but the world outside that one meaningful object dims, and those tasks requiring consciousness, such as answering questions during a talk, suddenly seem almost impossible.
Thus one major factor in stress is the inappropriate labeling of a multitude of safe events as life threatening. This in itself arises out of a combination of the primacy of our primitive, unconscious drives in controlling our thoughts and behaviors, and the plethora of habits we form in life, partly in the service of such impulses.
Our propensity for chunking, for consciously seeking out those little habitual nuggets, in other ways so successful in giving us control of our environment, can fail catastrophically when applied to our inner emotional world. It’s easy to underestimate the dizzying extent to which our lives revolve around the deep-seated chunks we’ve developed over the years. We are born utterly defenseless, with few instincts, but have minds exquisitely built for learning. Virtually every aspect of how we move, act, or carry out our daytime profession or evening hobbies is little more than a vast set of chunks we’ve learned over a lifetime. From the way we greet our parents on the phone to how we brush our teeth to the way we turn off our computer, every little detail of our lives involves the recalling of a piece of structured memory, a well-worn strategy, so that we have a fine-grained control over our world and an awareness that’s free to notice and react to new or complex events.
Amid these myriad chunks, though, there will be some examples in all of us that cause us to react in an unhelpful, irrational way to a given event. For depressives like my wife, not getting absolute top marks on a test might trigger a set of thoughts and memories that will cause her to think she’s utterly stupid, for instance. I can occasionally feel nervous talking to certain people not because of what they may say to me, or even what they ever did say, but simply because I once felt nervous in the past when talking to them, and this has become an inextricable habit. Because these are such well-used chunks, we are barely aware of them, just as we are barely aware of the mechanics of performing a forehand stroke in tennis.
This destructive form of chunking is particularly relevant to those with a mental illness. They might initially inappropriately label a given event as presenting an immense threat, as many of us do, but then fail to notice there was no threat after all. Instead, they may consciously chunk the link between the event and the level of danger so that it becomes reinforced and well established. Once this crystallizes in their minds, they will then repeatedly feel unavoidably, intensely threatened by these and any similar experiences. This can easily be compounded by further little chunks or tricks that are designed, in vain, to help. For instance, someone may be terrified of seeming awkward and foolish in social situations. But developing the habit to avoid all social moments means that this individual can never discover evidence to counteract his fears. Someone else may be terribly self-conscious of a small spot on her face, so she develops the habit to smother her whole face in thick makeup whenever she interacts with people, which means that she seems abnormal for this reason instead.
So while we are ingenious at understanding and innovation, we are unfortunately just as adept at forming thousands of personal strategies that can create chronic traps of stress and suffering, handing the advantage away from the prefrontal parietal network and to the amygdala. And when we are repeatedly exposed to stressful or frightening situations, then a damaging neural bias can develop: Our brains become entrained to overactivate the amygdala. This in turn can create a negative feedback loop that further inhibits activity in our prefrontal parietal network, reducing both our conscious space to deal with problems and our conscious control to filter out unhelpful thoughts and feelings.
The situation can then become semipermanent, with this imbalance continuing outside of episodes. For instance, if depressive or anxious patients are shown fearful stimuli in the scanner, then, understandably, they have greater amygdala activity than controls. But even if they are performing a neutral task requiring working memory or attention, these patients show reduced activity in parts of the prefrontal parietal network, as if these regions were chronically constricted, regardless of task.

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