We Are Our Brains

by D. F. Swaab

  People are scared stiff of death. For this to change, they need proper information about the last stage of life, long before the time comes to die. In 2002 I responded to the fierce debate about introducing civic integration courses for foreigners—a discussion scarred by xenophobia—by urging the Health Council to make it compulsory for everyone in the Netherlands to do a civic disintegration course. At the request of the council’s chair I drew up a debating paper on the issue, registered for posterity under the number 655-84. We had an animated discussion, but I wasn’t at all surprised that the recommendation didn’t become part of the formal advice given to the government by this respectable body.

  Yet I would still very much like to see an “exit course” of this kind set up for the general public and, in an amended form, for trainee doctors. It would cover all of the problems associated with the end of life, like euthanasia, pain relief, palliative sedation, and terminal dehydration. (On this latter point: In their book Way Out: A Dignified End to Life on Your Own Terms, Boudewijn Chabot and Stella Braam write that terminal dehydration need not be a terrible form of self-euthanasia if the right preparations are made, the mouth is kept moist, and a doctor provides the necessary medication in the final stage.)

  Assisted dying also needs to be discussed. The stance of the Dutch Voluntary Life Foundation (SVL) on this is, “We are entitled to choose our time of death and to obtain the means to achieve this in a humane manner.” The Dutch Association for Voluntary Euthanasia distinguishes three groups whose needs aren’t met by the current statutory procedures: people with dementia, chronic psychiatric patients, and old people who feel that their time has come. As far as the first two categories are concerned, the current euthanasia act has been applied in practice and is found to be usable (though doctors will only very exceptionally be prepared to countenance assisted dying in the case of psychiatric patients). However, for people who feel that they have reached the end of their lives but aren’t terminally ill, the law needs to be changed. Yvonne van Baarle, former secretary of the Arts Council, set up a group to try to bring this about. We started an online signature campaign calling for this issue to be discussed in the House of Representatives. To our amazement, we collected the forty thousand required signatures within four days. Given the enormous positive interest, it’s amazing how much abuse we received; our group was dubbed the “death squad.”

  Decisions by patients to refuse treatment (living wills) are also frequently problematic. Although doctors are obligated by law to abide by such decisions, they almost never do. Yet resuscitation can sometimes be unwise or even, as the Dutch doctor Bert Keizer memorably summed it up, “an extreme form of abuse.” While still an intern, I once saved somebody’s life in this way, and I regret it to this day. The patient suffered a heart attack as the nursing staff were wheeling his bed into the ward. I immediately put my newfound knowledge into practice and managed to resuscitate him. Shortly afterward we received his medical file. It turned out that he had a lung carcinoma that had grown into his heart. In the days that followed, I sat by his bed day and night as he struggled for breath, constantly clearing his blocked airways. I could have saved him all of that misery if I hadn’t resuscitated him! Things are changing, though, and Ruud Koster, a cardiologist at Amsterdam’s Academic Medical Center, has shown that the chances of survival after resuscitation have improved considerably. Indeed, the odds have more than doubled over the last decade, with people now surviving heart attacks in 20 percent of cases. The availability of increasingly effective automatic external defibrillators (AEDs) and better treatment prevent significant brain damage in over half of heart attack survivors. Cooling a patient’s body temperature down right after resuscitation can prevent much of the brain damage caused by the release of toxins after a period of oxygen deficiency. And having a heart attack near an AED gives you an optimal chance of survival. There seems to be less and less reason for NVVE members to carry “do not resuscitate” medic alert emblems. On the other side of the coin, in nine cases out of ten, resuscitating a newborn baby for more than ten minutes without a heart response leads to severe brain damage and should therefore be abandoned. How many would-be parents are aware of that?

  After death—which, like it or not, is inevitable—you can donate your body “to science,” which means that it will be used for medical students to learn anatomy. There’s nothing wrong with that, but if you really want to help science, you’d be better off donating your brain to the Netherlands Brain Bank, which has provided five hundred research groups around the world with brain tissue from over three thousand postmortems, resulting in hundreds of publications with new insights into neurological and psychiatric disorders (see later in this chapter). It can also be clinically important to consent to a postmortem, which is carried out to establish whether the diagnosis and treatment were correct. At present, such consent is requested at the moment when someone has just died and all the relatives are numb with grief. I was recently present on one such occasion, and it was obvious from the way the trainee internist put the request that he didn’t expect the relatives to agree to a postmortem. Indeed, everything he said seemed to militate against it, perhaps because it would save him a lot of work. Doctors are insufficiently trained to discuss this topic, which is especially sensitive when someone has just died. Such a fraught time is of course the worst possible moment to approach the family on this matter, and it’s no wonder that the number of postmortems has declined considerably.

  Topics that need to be discussed well in advance include brain death, tissue transplants, and the transplant of organs and corneas. Of course the same applies to burial or cremation. Other issues that an exit course would need to cover are Alzheimer’s cafés, active donor registration, preparing a body for burial, embalming, coma and related situations (see chapter 7), near-death experiences (chapter 16), advice on euthanasia, cultural differences affecting the issues surrounding the end of life, the legal aspect of these issues, the molecular biology of life and death (see earlier in this chapter), mummification, non-heart-beating donation, psychological problems at the end of life, and living wills.

  So even if there isn’t a life after death, death itself gives us a lot to think about. It’s so much easier for everyone involved if they know your views on this issue and have plenty of time to discuss them with you. As for me, my brain is going to the Netherlands Brain Bank. If I have time, I will give my colleagues written instructions as to what they should especially look for, along with some technical suggestions on how to go about it, which will undoubtedly irritate them. The rest of my organs and tissue can be used for transplants—that’s if anybody still wants them, because they’ve seen quite a lot of use already. And if doctors think that a postmortem is useful, they have my consent to perform one. I don’t care what happens to the rest of me. That’s a matter for my family to decide.

  If you have any more suggestions for the exit course, I’d like to hear them. Are you looking forward to it? The course, I mean. For I wish you a healthy and enjoyable life that lasts as long as you want it to.

  NETHERLANDS BRAIN BANK

  The bank that takes your thoughts into account.

  To find out the cause of brain disorders, you need to study the brain tissue of dead patients. In the late 1970s, however, it took me four years to obtain five clinically well-documented brains of Alzheimer’s patients, even though there were one hundred thousand such patients in the Netherlands. This was because they didn’t die in a teaching hospital but at home or in nursing homes. And it was impossible to obtain control material, because no one saw any point in carrying out postmortems of patients who didn’t have brain disorders. But every piece of brain tissue from a patient with a brain disorder has to be compared with exactly the same piece of tissue from someone of the same age and sex who didn’t die of a brain disease, who died at the same time of day, from whom the tissue was obtained at the same interval after death, and so on.

  That’s why in 1985 I took the initiative to se
t up the Netherlands Brain Bank (Nederlandse Hersenbank, NHB), which provides researchers with well-documented brain tissue. The neuropathologists of Amsterdam’s VU University were involved right from the start. In just over twenty years, the NHB has provided five hundred research projects in twenty-five countries with many tens of thousands of pieces of brain tissue from over three thousand donors (www.brainbank.nl). In 1990 it won an award for providing a good alternative to animal research, and in 2008 Princess Máxima, the wife of the Dutch crown prince, honored it with a visit.

  At present, the NHB has two thousand registered donors who have given consent for a postmortem of their brain and for their brain tissue and medical data to be used for research purposes. When a donor dies, his death is established by an independent doctor and the NHB is contacted immediately. The donor has to be transported as quickly as possible, usually within two to six hours, to the VU Hospital for a postmortem. Around seventy pieces of brain tissue are dissected, eight of which will be used to establish the diagnosis. The remaining pieces are frozen at -80°C, cultured, or prepared in some other way and sent to the research groups. What is unique to the NHB is that the tissue is made available so soon after death. This is only possible because donors and their families have completed all of the paperwork in advance and know exactly what will happen when the donor dies. The undertaker, too, knows that speed is of the essence. I was once called by the police, who had stopped a speeding undertaker and were reluctant to believe his story that the deceased needed to be taken to the hospital as quickly as possible. But when another undertaker got stuck in rush-hour traffic, a police officer on a motorcycle escorted him down the hard shoulder with flashing lights.

  The donors show great commitment. A donor with MS once called me to say, “I want to see the enemy.” So he came to the brain bank, where we mounted a microscope on his wheelchair table and the director showed him sections of brain tissue from MS patients. We get the strangest requests. Somebody once asked whether a relative could combine NHB donorship with donating organs for transplantation and their body to science. When I asked which relative of his he had in mind, he answered, “My mother-in-law.” He seemed eager to make sure that nothing of her came back! We have also had our fair share of legal problems. In 1990, we launched a campaign to recruit MS donors, which resulted in our being sued by the husband of someone with MS. He thought that MS wasn’t a brain disease but a muscular disease, arguing, “My wife’s not mad!” We were also able to reassure a donor who asked if we would postpone the postmortem until her aura had dissipated.

  It certainly isn’t an easy decision to register as an NHB donor. Sometimes it helps when I tell people that I’m always very reassured to think that, whatever stupid things I say or do while I’m alive, at least my brain will be put to good use by the NHB after I’m dead.

  HERBS FOR LONG LIFE AFTER DEATH

  That it will never come again

  Is what makes life so sweet.

  Emily Dickinson

  Traditional Chinese medicine has countless remedies that are believed to prolong life. It’s also often said of the many delicious dishes eaten in China that the food in question is good for your body or for a certain organ and that it guarantees longevity. When I say that I’m not so much interested in a long life as a good and interesting life, people tend to look a bit bewildered.

  However, while in China I did witness the power of medicinal herbs to conserve bodies over a long period of time. My family and I had returned to Hefei, to the Medical University of Anhui, where I’m a visiting professor, when I heard for the first time of a region known as the Jiuhua Mountains. A monk by the name of Wuxia, who lived there at the time of the Ming Dynasty (1573–1619), succeeded, over a twenty-eight-year period, in copying out eighty-one parts of the Buddhist scriptures using blood from his tongue and gold dust. He’s alleged to have died at the age of 126, and his body is said not to have decayed at all in the three years after his death. The other monks, who believed that he was the reincarnation of the living Buddha, gilded his body and preserved his mummy, known as “Monk Longevity,” in the Longevity Palace. Apparently, five-hundred-year-old mummies were also preserved and venerated in other monasteries in the Jiuhua Mountains. I didn’t understand how that was possible, because the climate in that region is extremely damp. My first Chinese PhD student, Zhou Jiang-Ning, who had meanwhile become a professor at Hefei, suggested that if I was doubtful, I should go and take a look. My wife and daughter decided to join me. The university lent us a car and driver, and we were accompanied by a Chinese doctor, Dr. Bao Ai-Min, who interpreted for us.

  After a six-hour drive in the darkness we reached the mountains at such a late hour that the monasteries and the many temples were shut, so we spent the night in the little town of Jiuhua. The next morning we returned to the monasteries, where Buddhist monks were praying around a glass case. In it we could indeed see a mummy covered in gold paint and sitting in a prayer position. The living monks praying in front of it were instructed by the head monk to make way for us so that we could inspect the mummy. The structure of the body was perfectly intact; it could have been used for an anatomy demonstration. The individual muscles were clearly visible through the dry, thin skin. Every monastery in the Jiuhua Mountains had one or more of these “flesh bodies”—the rather blunt name given to the mummies. With the help of our Chinese interpreter, I asked the head monk how it was possible that the body of this particular monk had remained intact so long after his death. “Because he is holy,” came the enlightening answer. In a jocular mood, I called Zhou in Hefei to tell him that we had found the solution to the puzzle: “He is holy.” According to Zhou, monks who felt they were nearing the end of their lives stopped eating normal food. Instead they ate special herbs, sitting in a vat in which they were submerged up to the neck in a mixture of herbal solution, carbon, and lime. In that way they could sometimes dry and preserve their own bodies before they actually died. Those who did so were deemed holy. Meanwhile, my daughter had been invited to join the monks in prayer. They were extremely kind to her, explaining the mysteries of Buddhist prayer. The striking combination of the small, shaven-headed Chinese monks and my tall daughter, with her long blond hair, joined in prayer made everyone cheerful. To what extent her participation in the prayer contributed to the mummies’ further preservation is something that only time will tell. I’m afraid I haven’t yet managed to get ahold of the recipe of the herbal solution.

  20

  Evolution

  It is notorious that man is constructed on the same general type or model as other mammals.… The brain, the most important of all the organs, follows the same law, as shown by Huxley and other anatomists. Bischoff, who is a hostile witness, admits that every chief fissure and fold in the brain of man has its analogy in that of the orang[utan]; but he adds that at no period of development do their brains perfectly agree; nor could perfect agreement be expected, for otherwise their mental powers would have been the same.

  Charles Darwin, The Descent of Man

  NEGOTIATION AND INCREASE IN BRAIN SIZE

  Bigamy is having one husband too many. Monogamy is the same.

  Oscar Wilde

  Over the course of evolution, our brain size and intelligence have increased enormously. Intelligence entails problem-solving ability, speed of thought, capacity to act purposefully, rational thought, and the ability to deal effectively with one’s surroundings. There are many different kinds of intelligence—linguistic, logical, mathematical, spatial, musical, motor, and social—so IQ is rather a limited way of testing it. The link between brain size and intelligence has nothing to do with the absolute size of the brain. The human brain, weighing in at three pounds, is of course by no means the largest: That record belongs to the sperm whale, with its nearly twenty-pound brain, while the brains of elephants weigh ten and a half pounds on average. In fact, an elephant named Alice who lived in Luna Park, Coney Island, had a brain that weighed thirteen pounds. But whales and elephants are by
no means as intelligent as humans. The relative size of the brain compared to the animal’s body, however, does have a clear correlation with the quality of the brain as an information-processing machine, as Darwin established back in 1871 and the Dutch neuroscientist Michel Hofman calculated a century later.

  A better measure of the level of evolutionary brain development is the encephalization quotient (EQ), a relative measure of an animal’s brain weight on top of what is needed to regulate body functions. Humans indeed score by far the best using this measurement. EQ is largely determined by the development of the cerebral cortex. The increase in our brain size during evolution was caused by an increase in the number of building blocks (neurons) and their connections. So the number of neurons in the cerebral cortex is a good measure of intelligence. These are grouped in functional units called columns. Although the cerebral cortex grew enormously over the course of evolution, the cross sections of the columns remained almost identical, around half a millimeter. It was an increase in the number of columns that caused our brains to grow bigger and the cortex to become convoluted in the process. Despite all these changes, the blueprint for the brain remained the same, so the difference between the brains of humans and those of other primates is largely one of size. This evolutionary in crease in brain size greatly increased our information-processing ability and went hand in hand with longer pregnancy, a longer period of development and learning, longer life expectancy, and fewer offspring. During the course of human evolution, skull content has more than tripled and life span has doubled in a “mere” three million years.

  Various hypotheses have been put forward to account for the evolutionary pressure that led to larger brains. An initial theory was that primates’ brains provided an evolutionary advantage through the ability to use tools, which increased food supply. It was then suggested (the Machiavellian intelligence theory) that larger brains were a response to the demands of a socially complex existence, causing individuals to invest in social strategies that promoted long-term survival of the group. A clear correlation has indeed been found between the size of primates’ cerebral cortex and the size and complexity of the social group. Primates started to live in social groups around 52 million years ago, when they abandoned their nocturnal existence and it became safer to band together. The complexity of life in groups is strongly determined by pair formation and monogamy, both of which place considerable demands on the brain. They require optimal selection of a fertile partner as well as complex negotiations between partners. The intricacy and intensity of such relationships—an issue familiar to us all—appears to have placed strong evolutionary pressure on the brain to grow. The mechanism of monogamous partner choice in humans is thought to have developed as far back as 3.5 million years ago. It has proved its evolutionary advantage in terms of protecting the family, but it continues to place an enormous burden on our brains.