Co-authored by Dr. Rudolph E. Tanzi
Current brain research is hot on the trail of mysteries that need solving. Current imaging techniques can show, with remarkable precision, what happens in specific parts of the brain when we feel an emotion, for example. Eventually, neuroscientists may be able to pinpoint the exact process that leads to the emotion of love. Indeed they already feel that they are close, since there's a map for tracing the hormones that make falling in love feel ecstatic, along with the areas of the brain responsible for emotions.
But close does you no good if your model has a serious flaw. In this case, the flaw is to assume that the physical mechanisms associated with love are the same as love itself. What if love takes place in the mind rather than the brain?
To many, that's a distinction without a difference. The mind is invisible, yet everything it thinks or feels requires a physical response in the brain. If you know what the brain is doing, you know what the mind is doing, or so the scientific method, based on materialism, holds to be true. But a huge mystery, known as the mind-body problem, is being begged. As long as we ignore the mind, we may be making profound mistakes about the brain.
The words "I love you" give us a perfect example. Imagine that you are sitting close to someone who has not made clear what he or she feels. The moment is right; the mood is intimate. In your ear you hear the words "I love you." Stop action. If we ask a neuroscientist what happens next, he will unfold a trail of physical events. Air molecules vibrate when those words are spoken, and in turn they vibrate the ear drum. Tiny bones in the middle ear transmit the signal, which gets turned into electrochemical reactions in the inner ear. As soon as electricity and chemicals are involved, we are in the precinct of the brain, which goes to work rapidly. Various areas light up, involving a complex interaction between those areas that process sound, meaning, memory and emotions. Even if it takes years or decades for neuroscience to trace this pattern exactly, the result is the same: Your heart jumps for joy, you flush and the delight of hearing "I love you" overtakes your body.
Or does it? What if you don't welcome those words? Instead, this was the moment, perhaps, when you were going to end the relationship. The physical trail remains the same, but something is drastically different: the meaning of the words as they apply to you. The dictionary definition of "I love you" isn't in doubt. Yet, if you think about it, every response imaginable is available to us when we hear "I love you," from horror (if a serial killer says them) to indifference (if you've heard it too many times) to joy. As for the body, it too is capable of any response -- you might feel nothing, or you might faint dead away. How is this possible?
Of course, we each hear the words "I love you" in a personal context, involving our own associations and memories. A gentle "I love you" might invoke memories of your mother's arms when you were a child. Individual meaning gets shaped in the brain's memory centers. But memory has its own baffling mysteries. One of us (Rudy), a Harvard neuroscientist, asked dozens of colleagues at a scientific conference, "Where are memories stored?" Instantly, everyone replied, "In the brain, of course." He pressed the point. "Where exactly in the brain? In neurons? If so, where in the cellular structure? After hemming and hawing, most had to concede that no one really knows. We know that synapses fire to retrieve a memory, but we do not actually understand how or where memories are physically stored in the brain or, for that matter, whether they can be physically located at all.
Meaning occurs in the mind, and the brain obeys the mind. They are not the same thing. A radio plays music, but it doesn't create music. A radio is dependent on the station you tune it to. Meaning is like tuning in but more subtle. You don't turn a dial; you automatically know what the meaning is, and if you don't, what happens? Your mind tries to straighten out the meaning. Your brain doesn't accomplish this task. Maybe the person whispered "I love U2." There's a huge difference between loving a rock band and loving a person who might love you back.
Can we really claim that brain tissue, which is made up of organic chemicals and water, can tell that "I love you" leads to joy while "I love U2" leads to a mild "That's nice. I do, too"? No, we can't. It's a mistake to attribute to physical things -- cells, molecules, atoms and so on -- what really belongs to the mind.
We aren't talking metaphysics, although science often takes that escape route when its faith in materialism is challenged. So let's leave aside the mind. There is no physical explanation for why the body reacts as it does to words. Consider that you hear any of the following sentences:
Your life savings are gone.
Look out, a rattlesnake!
Everyone agrees that each of these causes a terrifically different reaction in the body. Yet if you hear them spoken, each sentence beg ins with the tiniest vibration of the ear drum, and the brain signals that come next are also barely measurable in microvolts of electricity and a few hundred of thousand molecules of messenger molecules. Yet these tiny, tiny events get amplified enormously. The adrenaline rush that sends you running in panic from a rattlesnake represents millions of times more energy than the words that caused them. The words "It's bedtime" cause an equally massive amplification but in the opposite direction, toward relaxation and shutdown of the body for sleep.
It's well known that the human body depends upon homeostasis, the ability to keep very complex systems in balance and to return to a state of balance when it is disturbed. Yet words cause us to deliberately go out of balance, and there's no physical mechanism to explain it. Meaning explains everything, since "It's bedtime" and seeing a rattlesnake of course hold totally opposite meanings. But if you say that the brain creates the meaning of words in the cerebral cortex -- the standard textbook explanation -- you have no way of escaping a dead end. The physical world is ruled by cause and effect. We cannot say that a feather can dust the table one minute and push over a boulder the next. Yet these same tiny molecules of brain chemicals manage to do just that. One minute you hear some words and decide to go to sleep; the next minute you hear other words and instantly run away on high alert.
There is no doubt that your body can amplify signals. There's no doubt that different words have different meanings. Yet if you try to put these two facts together using just the brain, you can't. A tiny virus can enter the body and cause every system to break down, leading to death. It's as if a baseball broke a window in a skyscraper and the whole building fell down. But that's not really a mystery, because the virus divides, and by a simple train of cause-and-effect, its toxins are amplified until the immune system is overwhelmed. But there is no explanation for how a few words can create such a powerful effect that it gets repeated, day after day, for years. The things we worry and obsess over, the grief that lingers on and on, the game-winning touchdown and the girl who got away -- all can be amplified into bodily reactions from a state of near zero, since memory requires no expenditure of energy.
Some mysteries are worth pondering because they fascinate us. Others are worth pondering because they can shake our whole worldview. The mystery of "I love you," we believe, is the second kind.
Deepak Chopra, MD, FACP
Dr. Rudolph E. Tanzi
Joseph P. and Rose F. Kennedy
Professor of Neurology,
Harvard Medical School
Director, Genetics and Aging Research Unit,
MassGeneral Institute for Neurodegenerative Disease
Massachusetts General Hospital