Introduction
Imagine your mind is a yard on a clear March day. You’ve been offered a chance to walk around. You may choose to clear fresh paths through the brown winter muck, pick up bits of trash you forgot were buried under all that ice and snow, decide what new seeds to plant and where. You’ve been told your soil is rich—much richer than you thought—and now you are sure that with time and attention and a lot of gritty work, you can grow almost anything. You roll up your sleeves and take stock. What habits of mind will you dig up and toss on the compost heap? What mental skills and emotional states, what beliefs about yourself and the world will you choose to cultivate?
Little more than a decade ago, the physical landscape of our minds was perfectly invisible to us and, for all we knew, as fertile and productive as it was ever going to get. Even if we were aware of our thoughts, ideas, and emotions, we had no way of watching the neural activity associated with mental phenomena arise, do its thing inside our heads, and pass away. We had no way of watching that activity actually alter and strengthen our neural networks. Now, thanks to powerful new imaging tools like functional MRI (fMRI) and positron emission tomography (PET), we can watch the organ of the mind in action, and what we see is exhilarating: The brain has the capacity to heal, grow, and change itself in ways that before were thought impossible.
Conventional scientific wisdom used to paint a starkly different picture of the adult brain, one in which its physical structure was essentially immutable. By the age of three, the story went, most neural networks were in place, and by late adolescence, our temperament—our baseline chemical state of happiness or irritability—was thought to be fixed. If we had always been a sunny kid, our outlook would probably tend toward the golden for the rest of our lives, but for those of us born and raised on the dark side of the moon, we would probably always struggle with negative emotions like anxiety, sadness, and aggression. Compounding the depressing picture was the conviction that, were we to lose nerve cells through disease, aging, or injury, there was very little point in ever wishing them back.
Now we can watch our brains on-screen, healing and adapting to challenges, and we see that our genes and early experiences absolutely do influence our cognitive and emotional makeup in important ways, and that they absolutely don’t get to dictate who we become. This previously unappreciated flexibility and trainability of neural pathways is termed “neuroplasticity,” and it has transformed modern neuroscience into an intensely optimistic field where researchers seek new diagnostic techniques and therapies for patients recovering from structural damage and chemical imbalances due to traumatic brain injury, stroke, Alzheimer’s disease, emotional disorders, drug addiction, and chronic pain. Research into neuroplasticity isn’t just revealing how we can heal brain injuries and sharpen our wits, but also how we can strengthen key neural pathways to become happier, kinder, less fearful, and more effectual merely by changing the way we perceive the world and our reactions to it.
The idea that humans are especially resilient creatures isn’t new. Aristotle, for one, thought that the brain’s chief biological role was to cool the heart, which he took to be the true physical seat of thought, reason, and emotion. The brain “tempers the heat and seething of the heart,”1 the great philosopher wrote, and because “the heat in man’s heart is purest,”2 humans require much bigger brains than beasts. We are the wisest, the best tempered of animals, he conjectured, because our brains are big enough to cool our hot, hot blood.
Our knowledge about the brain’s regulatory role has evolved since Aristotle’s time, but there is a sense in which he got it exactly right. Images of the brain recovering from emotional disorders, traumatic memories, and addiction show that this remarkable organ can, in fact, “cool the heart.” The self-regulating brain can alleviate the intense physiological effects of primal emotions like anger and fear, and in doing so, it can heal emotional damage and protect the body. We may even one day learn to cure the excruciating cravings that keep many of us locked in cycles of addiction by consciously modulating activity in particular areas of the brain. It seems that we’ve always instinctually known that we are born to be highly adaptable—that we are gifted with extraordinary abilities to heal and change in the face of adversity—and now we are taking the pictures to prove it.
Cutting-edge imaging research also holds the promise of providing new diagnostic and therapeutic options for patients suffering from states of impaired awareness or—most harrowingly—from awareness without any ability to communicate with the outside world. A patient’s thoughts might be observed on-screen in ways that could be understood by others—an exciting possibility for families and friends who spend months or even years at the bedside of a loved one recovering from a brain injury. At one heartbreaking extreme, of course, are the patients who never recover any meaningful level of awareness. Stem-cell researchers are working hard to grow functioning neurons in the laboratory, but until such research bears therapeutic fruit, there are certain severe brain injuries—global neuronal loss due to prolonged oxygen deprivation, for example—that simply cannot be repaired.
Standard bedside tests for consciousness have remained largely unchanged for 30 years, as have the painful ambiguities that can accompany end-of-life decisions. Brain-imaging technologies may ease the agony of some of these complex choices by enhancing our understanding of the neural correlates of awareness. Pictures of the brain responding to the world may one day become a standard tool to clarify when medical interventions are working to extend meaningful life and when they are inappropriately and painfully prolonging death.
New imaging tools also mean new hope for age-related cognitive decline. Functional MRI, PET, and a revolutionary imaging substance called Pittsburgh Compound-B (PiB) have revealed that Alzheimer’s disease attacks different parts of the brain than those affected by normal aging, and that some brain systems, including some forms of memory, are left intact by Alzheimer’s. It is possible that these undamaged systems may be trained to help people afflicted with the disease to function better. And for those of us with a few million miles on the brain, there is more to be excited about: Research into new diagnostic methods may help catch the debilitating disease in its earliest stages (when drugs and other forms of therapy might be most effective), while other studies show that certain kinds of mental training can relieve the effects of “normal” age-related memory decline.
Tantalizing pictures of the brain are also emerging from the field of neurotheology, a branch of learning that seeks connections between spiritual experiences and mental activity. Neuroscientists have scanned the brains of spiritual practitioners as diverse as Tibetan Buddhists and Franciscan nuns, and have found striking similarities in their brain activity when they are in states of “higher consciousness”—states in which people stop sensing a separation between themselves and the world, in which their minds feel limitless, expansive, and in touch with God or spiritual insight. Researchers are also identifying neural pathways for spiritually significant mind states like empathy, compassion, and forgiveness, showing not only that prosocial emotions are skills that can be perfected through training, but that practicing them makes our brain circuitry more positive and responsive in ways that could be used to prevent depression and other mood disorders, bullying and violence, and even physical damage inflicted by our own negative internal states.
Pictures of the Mind looks at images across the full spectrum of consciousness—from impaired, to healthy, to “higher”—and what they tell us about the brain’s extraordinary capacity to heal after illness and injury, to adapt to new challenges, and to retrain itself in ways that can make us happier, healthier people, more attentive to our own needs and to the needs of others. This deepening knowledge about the organ of knowledge is transforming our basic understanding of the “self” from a static and limited entity to a vast and productive landscape—the ideal ground in which to cultivate conditions for well-being.
