We Are Our Brains (44 page)

In 1906, the American doctor Duncan McDougall weighed dying patients, placing them (along with their beds) on scales with a seesaw mechanism. After death he weighed them again, and he found that the head end of the bed had lost an average of twenty-one grams. McDougall concluded from the difference in weights that he had weighed the “soul.” It seems a strange experiment: Since the soul is said to be immaterial, it surely wouldn't weigh anything. The loss of weight when the heart stops beating is more likely to be attributable
to the redistribution of blood between the various organs. But the precise figure of twenty-one grams caught the public imagination and even became the title of a film. McDougall's subsequent finding, after another experiment, that dogs didn't become lighter at the moment of death tied in with Descartes's claim in 1662 that animals were “soulless machines.” In the 1930s, however, a Los Angeles schoolteacher by the name of H. Laverne Twining carried out more precise experiments, which showed that all animals lost a few milligrams or grams of weight at the moment of death, from which he concluded they had some sort of soul.

So throughout history, all cultures have postulated the existence of a soul. Nowadays, there is a field of study that you'd think was all about the soul: psychology. Yet psychologists don't study the soul, only behavior and, more recently, the brain. A “psychon” doesn't exist; a neuron does. When you die, you don't give up the ghost, your brain merely stops working. I've yet to hear a good argument against my simple conclusion that the “mind” is the product of the activity of our hundred billion brain cells and the “soul” merely a misconception. The universality of the notion of a soul seems merely to spring from mankind's fear of death, the longing to see the dear departed once again, and the misplaced, arrogant idea that we're so important that something must remain of us after death.

Some people still cling to the idea that the heart plays a special role when it comes to feelings, emotions, character, love, and even the
soul. The editors of the Dutch newspaper
NRC Handelsblad
once forwarded me a reader's letter, which read, “The professor keeps going on about the brain, but the heart, as the seat of the emotions, is the brain's exact counterpart.” I don't deny that we sometimes feel our hearts beating with excitement, but that's in response to a command from the brain, which prepares our bodies, through the autonomic nervous system, to fight, flee, or make love.

The mythical role of the heart is reinforced by anecdotes “proving” that donor qualities are transplanted into the bodies of people who receive heart transplants. In 2008, the Dutch newspaper
De Telegraaf
published the story of an American man who had committed suicide by shooting himself through the head. His name was Sonny Graham, and he'd received a heart transplant twelve years previously. The donor heart had come from Terry Cottle, who had committed suicide at the age of thirty-three. Sonny Graham had been so grateful for his new life that he'd started to correspond with Terry's widow, Cheryl. One thing led to another. “I felt like I had known her for years,” Graham told a local paper in 2006. “I couldn't keep my eyes off her. I just stared.” In 2004 Fox News reported that the widow married the man who'd been given her first husband's heart. Her new husband went on to kill himself in the same way as the heart's first “owner.” At the age of thirty-nine, Cheryl was widowed for the second time.
De Telegraaf
didn't conclude from this that it might not have been easy to live with Cheryl. No, instead it asserted, “And this breathes new life into the story that when you transplant an organ like the heart, the soul of the deceased is transplanted with it.” In fact
De Telegraaf
is rather partial to stories of this kind. The heading of one of its weekend supplements ran, “Does your soul live in your heart? Claire Sylvia (47) was given a boy's heart. She now whistles at girls and drinks beer.” Sylvia, who published a book about her experience in 1997, was convinced that she had inherited the characteristics of the young motorcyclist who was the donor of her heart and lung transplant.

The
Journal of Near-Death Studies
, a periodical that until recently I hadn't heard of, publishes many stories of heart transplant patients whose tastes or abilities changed to match those of their donors. Some stories tell of patients whose musical preferences changed. One tells of a man who, after being given a woman's heart, suddenly became mad about pink, a color that he'd loathed before the operation. Another patient, a woman who'd been given the heart of a chess player, claimed that she'd now mastered the game. And a man who received the heart of someone who had been murdered said that he'd seen the killer's face in a dream. The problem with accounts like these is that the heart recipients knew a lot about the donors, ranging from their sex, age, and cause of death to many other details about their lives. To take such anecdotes seriously, we need well-controlled studies in which heart recipients know nothing at all about their donors. A heart transplant is an extraordinarily serious, stressful, and life-threatening operation that can drastically affect personality for many years. Heart recipients often become more spiritual, feel guilty about the deceased donor, and feel that the latter lives on in their body. Their behavior is also affected by the heavy medication needed to counteract rejection of the transplanted organ. So people have every reason to feel different after a heart transplant. And how could a transplanted heart, which has no nerve connections with the recipient's brain, transmit complex information about the donor to the brain of the recipient in such a way as to influence their behavior?

Until well-controlled studies have proven otherwise, we must assume from the available clinical and experimental literature that all of our characteristics are located exclusively in our brains and that the heart is merely a pump that can be replaced without donor characteristics, good or bad, being transplanted along with it.

One of my PhD students gave me an analytical account of his two near-death experiences (NDEs), describing them with scientific interest:

These days, most people have heard of NDEs. Familiarity with the phenomenon increased after the Dutch cardiologist Pim van Lommel published his bestselling book
Consciousness Beyond Life: The Science of the Near-Death Experience
in 2007. NDEs can be caused by oxygen deprivation, extreme fear, high fever, or exposure to chemical substances. Twenty percent of people who suffer a heart attack say afterward that they felt a sense of tranquility, that the pain stopped, and that they thought they had died. Some have the sensation of leaving their bodies and seeing themselves lying down. Others feel as if they're traveling at high speed from a dark place into a tunnel with a bright light at the other end, find themselves in a beautiful landscape, or hear music. Some are reunited with deceased friends and relatives or experience divine apparitions, while others see their entire lives flash before their eyes. And all of this happens in less than a minute. The compromised brain responds to the situation by retrieving
an incredibly rapid stream of memories, thoughts, images, and ideas. Christians see Jesus, while Hindus see messengers of Yama, the god of the dead, coming to take them away. Memories appear to be recalled at much greater speed than normal, and people have visions of the future. At a certain point a border is reached, after which people return to their bodies and the NDE ends. Some people report that Jesus himself sent them back because their children needed them.

Van Lommel's achievement was to describe patients' near-death experiences in detail in
The Lancet
in 2001, sparking debate on the phenomenon in the medical world. He related how greatly changed his patients often were after an NDE, to the extent that their marriages frequently failed. People who have had NDEs lose their fear of death, become more religious or spiritual, and believe more in the paranormal. NDEs have such an overwhelming impact on many people that they really don't want to have them explained in neurological terms. They believe that they have been granted a glimpse of the hereafter; their lives take on a more spiritual and religious focus. My PhD student, an exception to this rule, remained a critical scientist even during and after his NDE.

Throwing Out Four Nobel Prizes

Unfortunately, Van Lommel doesn't take the same rational approach, allowing himself to be carried away by his patients' belief in paranormal explanations for NDEs. His pseudoscientific interpretations must be popular, because his book is selling like hotcakes. He categorically rejects any neurobiological explanation of NDEs, putting forward his own theory that allegedly explains in a single stroke not only NDEs but all spiritual and paranormal phenomena, including predictive dreams, reincarnation, seeing things at a great distance, and moving objects with the power of thought. According to him, consciousness isn't produced by the brain as we “shortsighted, materialist, reductionist brain researchers” think. No, according to him it's present “everywhere
in the universe,” simply being received by the brain in the way that “programs are received by radio or television.” According to Van Lommel, thoughts don't have a material basis either. Apparently he's unaware of recent experiments proving the contrary. Take the case of someone whose arm had been amputated who was able to control a computer mouse and a prosthetic arm by the power of thought, using equipment that registered the electrical activity of neurons. In other words, Van Lommel has gotten things backward: The presumed “radio” (the brain) makes its own programs.

Van Lommel claims that his spiritual theory is necessary because the brain lacks sufficient storage capacity for long-term memory. This is nonsense; he appears to be unaware that in 2000, Eric Kandel won the Nobel Prize for describing how short- and long-term memory are formed at the molecular level. Van Lommel also claims that our organisms lack the information necessary for our embryonic development and immune responses; he believes all this information to be stored in the universe. Once again, he appears to be unaware that in 1995 a Nobel Prize was awarded for the discovery of genes involved in early embryonic development, while in 1987, Susumu Tonegawa received the Nobel Prize for his discovery of the genetic mechanism responsible for antibody diversity. As a crowning touch, Van Lommel claims that DNA isn't the carrier of genetic information but merely receives this information from the universal consciousness. Can anyone seriously believe that Watson and Crick didn't deserve the Nobel Prize they won in 1962 for determining the structure of DNA? By dismissing four Nobel Prizes without a single scientific argument, Van Lommel shoots down his own book—or at least its scientific pretensions.

Generating Near-Death Experiences

NDEs can be caused by anything that impairs brain function, inducing a state between consciousness, dream sleep, and unconsciousness. NDEs have been reported in cases of severe blood loss, septic
or anaphylactic shock, electrocution, coma due to brain damage or cerebrovascular accident, suicide, near-drowning (especially in the case of children), and depression. NDEs can also be caused by excessive levels of CO2, hyperventilation, LSD, psilocybin, or mescaline and have been experienced by pilots accelerating too rapidly in fighter planes. They've also been reported in connection with ketamine, a drug used as an anesthetic.