We Are Our Brains

by D. F. Swaab

  Wegner has carried out an experiment that supports his theory. Person A stands in front of a mirror with his arms tucked out of sight. Person B stands behind him and stick his arms out under A’s armpits, where A’s arms would normally be. When B’s arms carry out commands that are given aloud (like “scratch your nose,” “wave your right hand”) A sees the movements in the mirror and feels as though he is controlling them with his will. Wegner’s work clearly shows that both actions themselves and the “conscious” idea of initiating an action are prompted by unconscious processes in the brain. You can’t oversee these processes, but you can interpret the resultant action. The “conscious picture” that our brains register when we carry out an action gives us the feeling that we have knowingly performed that action. But that feeling doesn’t constitute proof of a conscious, causal chain of events leading to the action. According to the Amsterdam psychologist Victor Lamme, the illusion of conscious will only occurs belatedly, when the information about the action being performed is transmitted back to the cerebral cortex. Wegner believes that the illusion of free will is necessary in order to give an action personal legitimacy. It’s like a rubber stamp saying “I did this!”

  In his famous experiments, Benjamin Libet showed that when we initiate actions, it takes half a second before our brains consciously register the action. His conclusion that “conscious” experiences are preceded by half a second of unconscious brain activity (“readiness potential”) raised serious doubts as to the possibility of acting from free will. Although Libet’s observations have been hotly debated, recent fMRI scans have shown that there are areas of the cerebral cortex in which motor actions are prepared for as much as seven to ten seconds before they are consciously perceived. And the time lag between action and consciousness has been demonstrated in numerous ways. In one experiment, people were given the task of quickly touching a spot that lit up on a computer screen. Their visual cortex worked with great speed. One-tenth of a second after the light appeared, it fired off a message to the motor cortex to initiate the movement to touch the light (fig. 22). If the processing in the visual cortex was interrupted by a magnetic pulse, the action was carried out, but the person wasn’t conscious of the screen lighting up. All of these observations support the idea that the notion of acting from free will is indeed illusory. Whether it’s possible, as Libet believed, that we do at least have the power of veto over an action as soon as we become aware of it (“free won’t”) remains to be seen. It’s of course equally possible that vetoing an action, too, is preceded by unconscious brain activity.

  But even if consciousness is somewhat slow on the uptake, it remains useful. We plan consciously (see chapter 13) and learn to drive consciously (a process that can be carried out automatically after a lot of training; see chapter 14). If you weren’t conscious of the pain caused by a wound or infection, you’d be unlikely to do something about it, and your chances of survival would be slim. What’s more, consciousness ensures that you try to avoid similar hazards in the future. The fact that many of our actions occur unconsciously doesn’t mean that we can’t act consciously when we pay attention. Driving a car on autopilot is fine until something unexpected happens that requires your attention. Then slow, conscious action takes over—with all its own inherent dangers.

  WHAT FREE WILL ISN’T

  Every brain is unique, so it’s not so unique to be unique.

  While Francis Crick had doubts about the existence of free will, he theorized that part of the prefrontal cortex, the anterior cingulate cortex, might provide a neural basis for will. (He meant “will” in the sense of “taking initiative,” certainly not free will as defined by Price—that is, the ability to decide to act or refrain from action without intrinsic or extrinsic constraints.) Antonio Damasio, too, believes the anterior cingulate cortex and the medial prefrontal cortex to be the source of both external action (movement) and internal action (thought and reasoning). In the case of Alzheimer’s patients, a strong correlation is indeed found between the degree of apathy and the shrinking of the anterior cingulate cortex. But that doesn’t constitute proof of the localization of “free will.”

  Many examples have been presented to brain researchers in attempts to undermine the theory that free will is illusory. Decisions to perform deeds of resistance, for instance, are cited as evidence for the existence of free will. One wonders whether that is such a good example, given that religious extremists who have been indoctrinated from an early age would see their deeds in the same light. And while we’re at it, the famous words allegedly spoken by Martin Luther when he appeared before the Diet of Worms in 1521, “Here I stand, I can do no other,” don’t sound like the expression of a completely free decision either.

  Science and art have often been hauled out to “prove” the existence of free will. The Australian electrophysiologist and Nobel Prize winner John Eccles invoked the creativity of the scientist as overriding proof of the existence of free will. Indeed, our brains are unique and can therefore produce unique poems or paintings or devise unique experiments. But this doesn’t constitute proof of free will. It’s not for nothing that researchers working independently and in different parts of the world often make the same “unique” discovery simultaneously. And this has always been the case. Darwin was forced to publish his theory of evolution much against his will, because Alfred Russel Wallace had arrived, entirely independently, at the same idea. The theory was made public in the form of a joint paper read out at a meeting of the Linnean Society in London on July 1, 1858. Darwin wasn’t present, as he and his wife were burying their son that day. Wallace wasn’t there either, because he was in the Far East. The joint paper didn’t prompt further debate. Even more remarkably, a Scottish gardener had already come up with the notion of natural selection just as Darwin was setting sail on the Beagle. However, as his idea was published in a book, no one took any notice of it. (This is still very much the case today. Any scientific article published as a chapter in a book is lost as a publication.) What this shows is that the time was apparently right for this entirely novel concept. If these men hadn’t come up with the idea, someone else soon would have. That doesn’t detract from the brilliance with which Darwin set out this theory, illustrating each step of his argument with countless examples in works that are not only scientifically significant but also highly readable.

  This phenomenon of independent but simultaneous discovery is also to be found in art. The precursors of artistic development go back about 164,000 years, to our common roots in Africa, but mankind appears to have “discovered” art about 30,000 years ago, more or less simultaneously in France, Australia, and Africa. The world’s oldest sculpture, a female figurine carved out of a mammoth’s tusk found in Germany, also dates from this period. These “unique” expressions of human creativity apparently depended on the stage reached by the brain in its evolutionary development. Similarly, the most influential factor in the “unique” experiments carried out by researchers appears to be the progress of scientific thought and the development of new technologies and instruments, enabling the next logical step to be taken.

  The uniqueness of scientific or artistic discoveries is therefore insufficient proof of the existence of free will. Better arguments are needed.

  FREE WILL AND BRAIN DISORDERS

  Free will is illusory, particularly in the case of mental disorders.

  Free will entails being able to predict the consequences of one’s actions. A person suffering from a brain disorder may be unable to do so. This can have legal implications, because under Dutch criminal law, a person who commits an offense for which they can’t be held accountable due to impaired development or a mental disorder isn’t criminally liable. In 2003, a resident of a nursing home, an eighty-one-year-old woman with severe dementia, murdered her eighty-year-old roommate, who also suffered from dementia. The Public Prosecution Service of course refrained from prosecution. Schizophrenia sufferers occasionally commit crimes of violence. In 1981 John Hinckley
Jr. tried to assassinate President Ronald Reagan. In 2003, Mijailo Mijailović murdered the Swedish foreign minister, Anna Lindh, believing that Jesus had commanded him to do so.

  Very few people will claim that these acts were committed out of free will. When a polite, nicely dressed lady suffering from Tourette’s syndrome, sitting with her handbag on her lap in her doctor’s consulting room, suddenly pours out a stream of tic-induced obscenities, she doesn’t do so of her own free will. But how far can this exception be taken? Can you hold a pedophile morally responsible for his sexual orientation if you know that it results from a combination of genetic factors and atypical brain development? His pedophilia certainly isn’t a free choice. How responsible is someone who, as a result of his genetic background and his mother’s smoking during pregnancy, develops ADHD and commits criminal acts? We know that malnutrition during pregnancy increases the risk of a child going on to develop antisocial behavior. How much free will can be attributed to him if he gets into trouble with the police? Can you hold a teenager fully accountable for committing an offense while he’s still getting used to a brain that has been completely reconfigured by sex hormones?

  The complexity of the concept of free will is also illustrated by alien hand syndrome, a rare neurological condition that occurs when communication between the two sides of the brain breaks down. This can happen when the link between the two hemispheres, the corpus callosum, gets damaged. As a result, the activity initiated by the individual sides of the brain can no longer be coordinated, and the patient loses their sense of control over one of their hands. Their “alien hand” carries out involuntary actions that may be completely at odds with those of the normal hand. One hand will be putting on a pair of trousers, while the other makes strenuous attempts to take them off. How would free will apply in such cases? One person with the syndrome described how she woke up several times in the night to find that her left hand was trying to strangle her. It was a detail seized upon by the makers of the film Dr. Strangelove, in which one of Peter Sellers’s hands is constantly wrestling to prevent the other from choking him to death. When the above-mentioned patient was awake, her left hand would try to undo the buttons of her dress against “the will” of her right hand. Her left hand also fought with the right in trying to pick up the phone. The feeling of having lost control of your own limbs and the lack of a sense that you’re initiating actions are terrifying; they create the illusion that someone else or something else is controlling those actions. Indeed, the patient in question, seeking to account for the fact that she apparently wasn’t in charge of her own hand, thought that it was being controlled “from the moon.” It seems that if we’re aware of what we do but lack a sense of autonomy (free will), our body feels like an alien object. It has accordingly been suggested that the illusion of acting out of free will might well be the price we have to pay for consciousness. In the case of alien hand syndrome there appear to be two wills in a single brain, each wanting something different. So the illusion of possessing free will also depends on effective links between the right and left hemispheres of the brain.

  The notion that we’re free to choose how to act isn’t just mistaken, it has also caused a great deal of misery. It used, for instance, to be generally accepted that our sexual orientation, that is, heterosexuality, homosexuality, or bisexuality, was a matter of choice, and since homosexuality is regarded as a wrong choice by all religions, it was until recently criminalized and regarded as an aberration. Indeed, it was removed from the ICD-10 (International Classification of Diseases) only in 1992. Before that time, all kinds of attempts were made to “cure” homosexuals of their supposed disorder by imprisoning them and subjecting them to all manner of terrible interventions and operations, none of which had the slightest effect. I’m curious to see how long it will take before society starts to think differently about other actions and behaviors that are now thought to be subject to free will, like aggressive and delinquent behavior, pedophilia, kleptomania, and stalking. Society’s acceptance of those behaviors as innate would have far-reaching consequences in the treatment of offenders.

  It is also sometimes claimed that one’s free will can combat physical ailments. Some argue that a positive attitude to certain neurological disorders like MS promotes healing. Not only is there no evidence whatsoever for this view, but one of its consequences is that if the disease worsens, the poor patient is told that he or she didn’t “try” hard enough to fight their illness!

  Wouldn’t it be better for us to accept that complete freedom of will is illusory? It isn’t exactly a new idea; as Spinoza said in his Ethics II, proposition 48, “In the Mind there is no absolute or free will.”

  18

  Alzheimer’s Disease

  AGING OF THE BRAIN, ALZHEIMER’S DISEASE, AND OTHER FORMS OF DEMENTIA

  The prospect that you’ll finally forget that you’ve forgotten everything and that this loss will no longer trouble you isn’t a consoling thought, because it signifies your ultimate erasure as an individual.

  Douwe Draaisma

  Life is sometimes allegorically portrayed as a staircase that we climb step by step, ascending as we develop and grow until we reach our prime and then start to descend around the age of fifty, as the aging process sets in. But when it comes to the aging of the brain, a better metaphor might be a film of our life being wound back to the start. Alzheimer’s reverses the stages of development so that sufferers gradually lose their personality and their faculties, culminating in a state of complete dependence that leaves them curled up in a fetal position, demented and effectively brain-dead (see later in this chapter).

  “Normal” brain aging and Alzheimer’s have a lot in common. First, age is the main risk factor for Alzheimer’s: The likelihood of developing the condition increases exponentially as you get older. Second, all the alterations found in the brains of Alzheimer’s patients are also present in old but dementia-free “control brains,” albeit to a much lesser degree and starting at a later age. Alzheimer’s can in many ways be seen as a premature, accelerated, and severe process of brain aging.

  Every living organism ages. Why is that? Probably because it takes less energy for nature to replace individuals every now and then with younger specimens than to keep the original organisms intact forever by constantly repairing damaged cells. This has led to the theory of the disposable individual, a notion that is, alas, reflected in the way society views the elderly, as a problem to be dealt with as cheaply as possible.

  Many Forms of Dementia

  Alzheimer’s is the most common form of dementia. Given demographic aging and the fact that age is the main risk factor for the disease, the number of Alzheimer’s patients is expected to double over the next thirty years.

  The only way of finding out whether someone with dementia was correctly diagnosed with Alzheimer’s is by carrying out a postmortem examination of their brain under the microscope to look for the telltale changes involved (fig. 29). That is because there are many other forms of dementia that can be distinguished from Alzheimer’s only through analysis of brain tissue. Brain infarcts and hemorrhages can cause multi-infarct dementia, very often combined with Alzheimer’s-type changes. Parkinson’s disease can also cause dementia; when it spreads to the cortex it takes the form of Lewy body dementia. The various types of dementia in the prefrontal cortex used to be collectively referred to as Pick’s disease. Nowadays a distinction is made between different frontotemporal forms of dementia caused by tau gene mutations linked to chromosome 17 (fig. 30). The first sign of such dementia isn’t usually memory loss but bizarre and inappropriate behavior. Alcohol abuse can lead to a form of dementia called Korsakoff’s syndrome, in which patients fill in the gaps in their memories with made-up stories that they firmly believe to be true. That’s not to say that they can’t remember anything at all. I was about to introduce myself to a Korsakoff’s patient when the person in question said, “I know you, aren’t you Dick Swaab?” It was rather chastening to discover that my mem
ory of faces is worse than that of someone with Korsakoff’s! In the early stages of the AIDS epidemic, dementia used to be a common symptom, resulting from the brain damage caused by the many different infections. Thanks to the new multitherapy approach, dementia in AIDS patients is now a thing of the past.

  I once gave a lecture at an Alzheimer’s café—an informal gathering for Alzheimer’s patients that has become popular in the Netherlands—and was approached during the break by a man of about forty-five who said that he was in the early stages of dementia. I responded that I could see no outward sign of it. He told me that he’d already had a few small cerebral hemorrhages that he knew would persist, ultimately resulting in dementia. I asked him if he had relatives in the little Dutch fishing village of Katwijk. “Yes,” he answered. “Your diagnosis is spot-on, Professor!” The reason I asked was that there’s a family in that village with a rare mutation that causes amyloid buildup in the blood vessels, leading to cerebral hemorrhage and dementia. Its members know exactly what fate has in store for them, because they have seen so many relatives deteriorate in this way. Yet it’s a very rare form of dementia, just like Creutzfeldt-Jakob disease, which is caused by infections in abnormal proteins. It can have a genetic cause but was previously also transmitted in brain operations, before surgeons knew that their instruments needed to be sterilized in a certain way. People have also been infected through corneal transplants and the pituitary extracts formerly given to children lacking growth hormones. These hormonal extracts, which probably come from Russia, are sometimes still found in gyms, where they are used by bodybuilders who want to increase muscle mass. It’s a highly risky business: You need only one Creutzfeldt-Jakob carrier to make the entire batch deadly.