We Are Our Brains

by D. F. Swaab

  People trying out herbal therapies often rationalize it by saying “There’s no harm in trying.” After all, the thinking goes, these are “natural” substances and therefore can’t hurt you. This is a misconception that I would like to set right. Herbs can be completely ineffective against the maladies they allegedly cure and yet be extremely dangerous. What’s more, most of the toxins we know of are also “natural” substances. That makes sense, because when a chemical substance affects our organism, it’s usually through a specific protein receptor, and we have receptors only for natural substances or chemical substances resembling them.

  Reading the medical literature on the possible toxic effects of “safe” herbs is enough to make your hair stand on end. A whole host of neurological and psychiatric disorders has been shown to result from the use of herbal medicine, ranging from vascular infections in the brain, swelling of the brain, delirium, coma, disorientation, hallucinations, cerebral bleeding, motor disorders, depression, muscle weakness, and tingling to epileptic seizures. Ginseng can cause insomnia, vaginal bleeding, and mania. Valerian can make you nauseous and give you a hangover. Thorn apple (Datura stramonium) can cause disorientation, while passionflowers can generate hallucinations. Taking kava-kava (Piper methysticum), sold as an antistress cure, can lead to life-threatening liver inflammation and cirrhosis of the liver, while ma huang (Ephedra sinica) can induce psychosis. Preparations of ma huang contain ephedra alkaloids, substances contained in diet products, pep pills, and “smart” drugs, and are also used to enhance performance in sports. These preparations have rightly been banned in the Netherlands. The ginkgo tree, which is common in China, has fan-shaped leaves that inspired Art Nouveau designs in Europe at the beginning of the twentieth century. Ginkgo is prescribed as a remedy for memory problems and dementia (it does have some effect, but even less so than Western drugs for those conditions, which are themselves not very effective) but can cause headache and dizziness. Eucalyptus can induce delirium. St. John’s wort (Hypericum perforatum) is taken for depression and has been shown to improve mood, but it can also cause anxiety and fatigue.

  Some herbs, especially Asian ones, are, moreover, polluted with heavy metals. And don’t let yourself be fooled: The argument that herbal mixtures have been used for centuries, for instance in traditional Chinese medicine, gives no guarantee whatsoever, either of effectiveness or of the absence of toxic effects. It’s also important to know that herbs can interact unexpectedly and dangerously with conventional medicines. St. John’s wort, for instance, can counteract oral contraceptives and disrupt the effect of antiretroviral drugs and Prozac.

  Armed with this basic knowledge and a critical attitude, let us now go online. Type in “herbal therapy” on Google, and you’ll get over 20 million hits for herbs against every kind of disease, along with all the rubbish spouted by the con artists who sell them. Read and tremble! Particular caution is advised when they try to sell you something that they claim has no side effects. Any medicine that works has side effects. If someone claims that a product has no side effects, there are three explanations: (1) It doesn’t work, (2) its side effects have never been tested, or (3) (the most likely) both (1) and (2) apply. The only one who will certainly benefit from the herbs touted online is the herb supplier himself.

  This doesn’t mean that herbs can’t contain chemical components that have a therapeutic effect. A great deal of work is being done in China to support traditional medicine with scientific research. Efforts are being made to identify the active chemical substances in herbs that have been used for centuries, but since TCM is based on the notion that drugs are most efficacious when there’s a mixture of active substances, Chinese scientists face a daunting task. But these substances are now being isolated and their effectiveness is being researched along Western lines by means of cell cultures and animal experiments. There’s considerable pressure within China itself to give TCM a scientific basis, and physicians who simply go on prescribing TCM according to ancient Chinese traditions are sharply criticized.

  Sometimes the isolation of chemical substances from herbs provides some familiar results. For instance, plants that are traditionally used against aging disorders turn out to contain a lot of melatonin. In the West, too, there are claims that melatonin is an antioxidant that inhibits the aging process, but there’s no hard clinical evidence to back the claims up. However, we do know that melatonin as a purely chemical substance is effective in restoring the sleep-wake rhythm in dementia patients, reducing nocturnal restlessness, and achieving modest improvements in memory. As far as I know, no controlled trials have yet been carried out to establish the same effect using herbs containing high concentrations of melatonin. In TCM, ginseng is prescribed for problems relating to sexual dysfunction. Animal experiments in the United States have shown that ginseng indeed increases libido, facilitates erections, and stimulates sexual behavior. Now these findings only need to be confirmed in a clinical setting.

  The effectiveness of traditional plant extracts is increasingly being tested in controlled clinical trials, just as in Western drug research. Sometimes the results contradict one another, as always happens in drug research. Some studies show that ginkgo leaf extract indeed causes slight improvements in older patients with memory disorders and dementia sufferers, while other studies show no improvement in memory function. A comparative analysis has been made between ginkgo and Western anti-dementia drugs (acetylcholine esterase inhibitors), which aren’t very effective and have many side effects. Nevertheless, the Western drugs scored slightly better than ginkgo, so it isn’t a magic bullet against dementia.

  Time will reveal the reasons for the discrepancies between the studies and show who is right. The important point is that TCM is now being investigated using controlled, Western methods, so that we will eventually know whether it can indeed be used to develop effective drugs that don’t have too many side effects and pose no risk of toxicity. The latter danger is far from imaginary. In 2006, samples of a TCM aloe preparation sold in Britain were found to contain 11,700 times the permitted level of mercury. It’s findings like these that are currently placing extra pressure on China to modernize TCM.

  17

  Free Will, a Pleasant Illusion

  Perhaps the conscious mental representations are afterthoughts—ideas thought after the deed to provide us with the illusion of power and control.

  Irvin D. Yalom, When Nietzsche Wept

  FREE WILL VERSUS CHOICE

  Here I stand, I can do no other.

  Attributed to Martin Luther when he appeared at the

  Diet of Worms in 1521

  It’s often claimed that human beings have “free will” because we make choices. This is faulty reasoning. Every organism constantly makes choices. The point of contention is whether those choices are entirely free. The American researcher Joseph L. Price has defined free will as the ability to choose to act or refrain from action without extrinsic or intrinsic constraints. Applying this definition, can we ever be said to make a decision freely? Back in 1838 Darwin wrote that free will was a “delusion,” arguing that people rarely analyzed their motives and usually acted instinctively. Indeed, free will is such a complex issue that philosophers have yet to agree on what it actually is, though it’s often said to have three components. First, an action is only free if you could also have abstained from it (you must have alternative options). Second, an action must be carried out for a reason. Third, you should feel that you’re truly carrying out the action of your own volition. But feelings are, of course, entirely subjective.

  No one who has experienced the suddenness and intensity of falling passionately in love will classify partner choice as a “free choice” or a “well-considered decision.” Plato was of exactly the same mind regarding the autonomy of this process. He regarded the sexual impulse as a fourth species of soul, located below the navel, describing it as “rebellious and masterful, like an animal disobedient to reason.” Spinoza was no believer in free will either. He d
emonstrated that in Ethics III, proposition 2, where he states, “An infant believes that of its own free will it desires milk, a hot-headed youth believes he freely desires vengeance, a coward believes he freely desires to run away; a delirious man, a garrulous woman, a child … believe that they speak from the free decision of their mind, when they are in reality unable to restrain their impulse to talk.” Spinoza shows that characteristics are innate. You can’t change them.

  Our current knowledge of neurobiology makes it clear that there’s no such thing as absolute freedom. Many genetic factors and environmental influences in early development, through their effects on our brain development, determine the structure and therefore the function of our brains for the rest of our lives. As a result, we start life not only with a host of possibilities and talents but also many limitations, like a congenital tendency to addiction, a set level of aggression, a predetermined gender identity and sexual orientation, and a predisposition for ADHD, borderline personality disorder, depression, or schizophrenia. Our behavior is determined from birth. This view—the polar opposite of the belief in social engineering that held sway in the 1960s—has been referred to as “neurocalvinism,” alluding to the doctrine of predestination that shaped Calvinist thinking. To this day, adherents of strict Protestant sects believe that God has predetermined the course of everyone’s life from the moment of birth, including whether you will go to heaven or hell.

  That a great deal is determined during our early development applies not just to psychiatric disorders but also to our functioning in everyday life. We may have a theoretical choice between a heterosexual and a homosexual relationship, but our sexual orientation, already programmed in the womb, doesn’t allow us to choose freely between these theoretical possibilities. We’re born into a linguistic environment that shapes our brain structure and function without us being free to choose our mother tongue. The religious environment in which we end up after birth also determines how we shape our spirituality (its level being genetically predetermined)—that is, whether our focus will be belief, materialism, or environmental concerns. In other words, our genetic backgrounds and all the factors that permanently affected our early brain development saddle us with a host of internal limitations; we are not free to decide to change our gender identity, sexual orientation, aggression level, character, religion, or native language. Nor can we decide to have a certain talent, or to abstain from thought. As Nietzsche wrote, “A thought comes when ‘it’ wants, not when ‘I’ want.” Our influence on our moral choices is also limited. We approve of things or reject them, not because we have thought about the matter so deeply but because we cannot do otherwise. Ethics are a product of our ancient social instinct to do what is good for the group, a finding that goes back to Darwin. So we’re left with the paradox that the only individuals who are still free to a degree (apart from their genetic limitations) are fetuses in the early stages of gestation. But they can’t exploit this limited freedom because their nerve systems are still too immature. By the time we’re adults, the capacity of our brains to be modified has become very limited and, along with it, the potential for our behavior to change. By then we have been issued with a certain “character.” And by then our last little bit of freedom is further curtailed by the obligations and prohibitions that society imposes on us.

  THE BRAIN AS A GIANT, UNCONSCIOUS COMPUTER

  When making less important decisions I have found it useful to weigh up all the pros and cons. Yet in the case of truly significant matters the decision needs to come from the subconscious, from somewhere within ourselves.

  Sigmund Freud

  We make a great many decisions “in a fraction of a second” or “instinctively” or on the basis of our “intuition,” without thinking about them consciously. We “choose” a partner by falling in love at first sight, and an accused man will tell the court in all sincerity that he killed the victim before he knew it. In his book Blink, the science journalist Malcolm Gladwell paints a fascinating picture of the important and complex decisions made by the unconscious brain in a couple of seconds. Yet this happens only after its internal computer has carried out a gigantic number of calculations. Just as today’s planes can fly and land on automatic pilot, without the assistance of a flesh and blood captain, our brains can to a very great extent function excellently without conscious thought. But they have to be trained to do so. It’s only by feeding the unconscious brain a huge amount of data over a long period of time that an art expert is able to “sense” that he’s looking at a forgery, and it’s only by seeing a great many patients that a medical specialist develops the “clinical glance” allowing her to make a diagnosis almost as soon as a patient enters the room. Functional scanning has shown that conscious reasoning involves different brain circuits from those used for intuitive decisions. Only in the latter case are the insular cortex and the anterior cingulate cortex activated; these areas are important for autonomic regulation. They also play a role in our gastrointestinal system, so it’s rather appropriate to say we make a decision based on “gut feelings.”

  Our brains have to work on automatic pilot to a very great extent. We’re continually bombarded with an enormous amount of information and unconsciously use selective attention to extract what is important to us. Even when photographs of naked people are flashed before an individual too briefly to register the images consciously, a heterosexual man’s attention will still be caught more by naked women than naked men. Homosexual men and heterosexual women will focus more on the images of nude men, while the response of lesbian and bisexual women falls between that of heterosexual men and women.

  Emotions also play an important role in unconscious processes. In the case of moral judgments, emotions are decisive. An area in the brain’s frontal lobe, the ventromedial prefrontal cortex, is crucial to solving moral dilemmas, like whether to sacrifice the life of a single individual to save many lives. Most of us find these extremely emotional decisions well-nigh impossible, but individuals with a damaged prefrontal cortex weigh them in a clinical, highly detached way. They don’t experience emotions like empathy or sympathy when faced with dilemmas of this kind.

  Decisions that involve social norms and values are apparently made on an emotional basis even when it’s possible to weigh them rationally. The products of conscious reasoning processes are by no means always superior to unconscious decisions. In fact, conscious reasoning can even get in the way of good decisions. According to psychologist Ed de Haan, it’s sometimes better to make important financial decisions, like buying a house, on the basis of intuition—that is, without conscious reasoning. Just like Dustin Hoffman in Rain Man, the autistic savant Daniel Tammet tried to win money at blackjack by counting cards in a Las Vegas casino. He lost very badly until he decided to use intuition instead, whereupon he started winning again (see chapter 9). When you drive to work in busy traffic you make hundreds of decisions in complex, potentially life-threatening situations completely automatically. You can also, as it were, “park” a problem at the back of your mind for a while, giving it no conscious thought, and then all of a sudden, while you’re doing something completely different, the solution pops up. In other words—in perpetual homage to Sigmund Freud—our behavior is for a very great part steered by unconscious processes. A hundred years later we have returned to the subconscious, but this time without the Freudian vision of repressed, infantile, sexual, and aggressive urges and other dubious claims.

  Physical factors, like temperature and light, can also greatly affect our actions. Outbursts of aggression can be triggered by long hot summers. A study of the 2,131 major conflicts of the last 3,500 years has shown that in both the northern and southern hemispheres the decision to go to war has tended to be made in the summer, while in countries near the equator such decisions are unaffected by the seasons. In other words, it isn’t military strategy or “reason” or “free will” but the temperature that appears to be decisive when taking the momentous step of declaring war.


  Of course, making so many unconscious decisions also has drawbacks. The racist and sexist views that we unconsciously hold are often unexpectedly influential, for instance in job interviews. But on the whole our brains have to function as efficient, unconscious computers that nevertheless make rational decisions. Unconscious, “implicit” associations enable us to make countless complex decisions quickly and effectively, something that would be impossible if we were to consciously weigh up all the pros and cons in every instance—it would simply be too time-consuming.

  Yet all these unconscious decisions leave no room for a purely conscious free will. This has far-reaching implications, because when we hold somebody responsible for their actions, we’re assuming the existence of free will, which—at least as far as most of our actions are concerned—simply doesn’t exist.

  THE UNCONSCIOUS WILL

  We must accept the fact that it is possible we know something without knowing why we know it.

  Malcolm Gladwell, 2005

  Because our overburdened brain constantly makes decisions using unconscious processes, Harvard psychologist Daniel Wegner speaks of an unconscious will rather than a free will. The unconscious will makes split-second decisions on the basis of events in our surroundings, a process that’s determined by the way our brains formed during development and by what we have learned since. The complex, ever-changing environment in which we live means that our lives can never be predictable, and the way in which our brains have developed means that there can be no such thing as complete free will. Yet we believe that we’re constantly making free choices, and we call this “free will.” According to Wegner, this is an illusion.