The Mind and the Brain (33 page)

We began our discussion of neuroplasticity by quoting from the Spanish neuroanatomist Santiago Ramón y Cajal’s description of the “nerve paths” in the adult brain as “fixed” and “immutable.” It seems only right, then, to close with another passage from Cajal, who despite his pessimism about the seeming lack of malleability in the adult brain nevertheless saw a glimmer of hope: “It is for the science of the future to change, if possible, this harsh decree. Inspired with high ideals, it must work to impede or moderate the gradual decay of the neurones, to overcome the almost inevitable rigidity of their connections.” The science of the future has arrived. And in what may be the most remarkable form of neuroplasticity, scientists are seeing glimpses that internal mental states can shape the structure and hence the function of the brain. Faced with examples of how the brain can be changed—from Taub’s stroke patients and Piacentini’s Tourette’s patients to Teasdale’s depressives and Merzenich’s dyslexics—I had become more convinced than ever that such self-directed neuroplasticity is real. It was time to explore how attention in general, and wise attention—mindfulness—in particular, wields its power.

In the autumn of 1997, I was laboring to rework my second book. One of the joys of my life,
A Return to Innocence
is based on a series of letters I exchanged with a sixteen-year-old named Patrick on how to use mindfulness to cope with the raging changes in body, mind, and brain that accompany the transition from adolescence to adulthood. As respite, I drove up to Santa Cruz that October to visit the forty acres of redwood forest I had been fortunate enough to acquire in the nearby town of Boulder Creek several years before. During the drive north, I tried to work through what I considered a key reason for the disagreement between the materialist-reductionist view I abhorred and the view of those who, in the philosopher David Chalmers’s words, “take consciousness seri
ously.” That disagreement, I was more and more convinced, largely turned on the differing perspectives the two sides took on a deceptively simple question: what counts as primary, or irreducible, data? To those who take consciousness seriously, it is not only permissible but even vital to count subjective phenomena—phenomena such as what consciousness feels like from the inside. Such subjective phenomena have not been reduced to phenomena of a different type. The feeling of pain, the feeling of red (as discussed in Chapter 1), the subjective experience of sadness—none has in any way been convincingly explained away as the mere by-product of the firings of neurons and the release of neurotransmitters. In 1997, no less than now, it was beginning to look as if maybe they never would be. From my perspective, they never could.

In a book published the year before,
The Conscious Mind: In Search of a Fundamental Theory
, Chalmers had advanced a thesis consistent with this view. He argued that contemporary neuroscience doesn’t even begin to explain how subjective experience arises from the electrochemical chatter of brain neurons. Such reductionist explanations fall so far short of the goal, Chalmers maintained, that the whole enterprise of seeking an explanation of consciousness solely in the stuff of the brain was fatally flawed, and therefore doomed from the start. Instead, Chalmers suggested that conscious experience is inherently and forever irreducible to anything more “basic”—including anything material. Perhaps it should instead be understood in an entirely new way, he said: perhaps conscious experience is an irreducible entity, like space, or time, or mass. No member of that triad can be explained, much less understood, as a manifestation of either of the other two. Perhaps conscious experience, too, is such a fundamental.

Yet Chalmers also believed in
causal closure
, the idea that only the physical can act on the physical: if a phenomenon is nonphysical (like consciousness), then it is powerless to affect anything made out of the tissues, molecules, and atoms of the physical (like a brain). Chalmers, good epiphenomenalist that he was, accepted
that consciousness is real and nonreducible but believed that it is caused by the brain and cannot act back on anything material. (Within a couple of years, as we saw in Chapter 1, Chalmers had modified this last part.) I, of course, disagreed vehemently with the idea of causal closure. My OCD data, not to mention twenty-five years of practice in mindfulness meditation, had persuaded me that the nonphysical entity we call the mind has the power to change the brain. Just before I left L.A., as I was struggling to find a way to explain my notions of mindfulness in
A Return to Innocence
, I hit on the idea of
mental force
. It was little more than a literary device, really, a way to convey the notion that through intense effort we can resist our baser appetites. And although I believed in the concept in a spiritual sense, I wasn’t yet thinking about whether such a mental force might have a physical reality.

That Chalmers did not subscribe to diehard materialism—and was quite a nice guy—had led to a budding philosophical friendship over the past year. A few weeks before, I had sent the first e-mail of my life—to Chalmers. “I’m really just checking to see if there is any consciousness on the other end of this,” I typed, full of doubts about this newfangled toy. Almost immediately Dave replied, “Consider it affirmed: consciousness exists.” So during my trip to Santa Cruz I arranged to drop in, with no firmer plans than to shoot the breeze and catch up with Dave. Which is how I came to be sitting with him on his porch that Sunday afternoon, overlooking Santa Cruz, and discussing all things mind-brain. Over a couple of beers, I began lamenting the terrible social consequences of materialism and my view that the less-than-laudable moral condition of America in general and Santa Cruz in particular (I was grumpy from overwork and have never been particularly enamored of the moral condition of Santa Cruz in any event) could be laid at the feet of nearly three centuries of materialist ascendancy. The reigning belief that the thoughts we think and the choices we make reflect the deterministic workings of neurons and, ultimately, subatomic particles seemed to me to have subverted mankind’s
sense of morality. The view that people are mere machines and that the mind is just another (not particularly special) manifestation of a clockwork physical universe had infiltrated all our thinking, whether or not someone knew a synapse from an axon. Do you know what the most addressable cause of all this moral decrepitude is?, I asked Dave. Materialism! Not the materialism of Rodeo Drive, SUVs, and second homes in Telluride, but materialism as a worldview, a view that holds that the physical is all that exists, and that transcendent human mental experiences and emotions, no matter what grandeur they seem—from within—to possess, are in reality nothing but the expressions of electrical pulses zipping along neurons. Chalmers wouldn’t be the first (or the last) to express incredulity that I was blaming the moral morass of the late twentieth century on a school of philosophy that most people had never heard of. Still, there was a hint of sympathy in Chalmers’s voice as he asked, “Do you really believe that?”

I did. Chalmers and I then tossed around the names of scholars who might be positing tenable, scientifically based alternatives to materialism. One was David Hodgson. Like Chalmers an Aussie, and a justice on the Australian Supreme Court, he had written
The Mind Matters: Consciousness and Choice in a Quantum World
, published in 1991. Although it may seem odd for a jurist to focus on something as abstruse as materialism and consciousness, materialism clearly poses a bit of a problem for a central tenet of the justice system—namely, that people exert free will in their actions, including their criminal actions. If actions are merely the inevitable consequences of hard-wired brain circuitry—or, pushing the chain of causation back a step, of the genes we inherit from our parents—then the concept of genuine moral culpability becomes untenable. The second researcher whose work suggested an alternative to materialist reductionism, said Chalmers, was a physicist. His name was Henry Pierce Stapp.

When I returned to Los Angeles, I got hold of a copy of Hodgson’s book, an imposing volume with a very long section on quan
tum physics smack in the middle. In a key passage on free will, Hodgson mentioned this same Stapp. A quick search on Amazon.com turned up a collection of Stapp’s papers, which I borrowed from the UCLA physics library. After spending a night that stretched into dawn with the collection, I purchased Stapp’s 1993 book
Mind, Matter and Quantum Mechanics
that February. The physics of mind-brain relations expounded in his book, I was startled to see, echoes William James’s theories, especially James’s belief in the reality of will and the efficacy of mental effort. Although hugely influential in the late nineteenth and early twentieth centuries, James’s ideas on the power of mind and the existence of free will fell into disrepute with the rise of behaviorism. Why? Well, who can nail down exactly what forces conspire to nourish a radically new scientific proposal or smother it at birth? James himself despaired of the possibility of scientifically demonstrating the efficacy of will. “The utmost that a believer in free-will can ever do will be to show that the deterministic arguments are not coercive,” he wrote. He knew that his theories of psychology—in particular his idea that “the feeling of effort” is an “active element which…contributes energy” to bodily action—failed to mesh with classical physics. In contrast, because the behaviorists’ theories rested on the classical, deterministic physics of the late nineteenth and early twentieth centuries, they easily trumped James’s. The behaviorist paradigm of John Watson held out the promise of a science of psychology in which researchers would discover the rules that govern why humans act, think, and emote as they do, much as they discovered the rules of electricity or hydrology. Behaviorism denies the reality of thoughts and emotions—indeed, of any sort of inner life. Instead of being afraid of something, it claims, we exhibit “a conditioned fear response” instead of loving someone, we show “conditioned love responses.”

Stapp suspected that James’s theories on mind and brain had been ignored largely because the physics of James’s time—the classical, deterministic physics of Newton—not only failed to support
his argument but even undermined it, casting it as so much mysticism. For James’s ideas to gain traction, then, they had to await not developments in neuroscience or psychology, but a revolution in physics. For as James himself realized, what he was saying about mind in general and will in particular—namely, that “the brain is an instrument of possibilities, not certainties,” and that “consciousness…will, if endowed with causal efficacy, reinforce the favorable possibilities and repress the unfavorable or indifferent ones”—directly contradicted the materialist perspective of the late nineteenth century.

In fact, James’s perspective on mind and brain is thoroughly modern, Stapp had observed in his 1993 book. James’s theories, Stapp argued, are actually more modern than those of the psychologists and philosophers who dominated the field in the decades after James’s death in 1910. Indeed, the consistency between James’s perspective on attention and will on one hand and the orthodox interpretation of quantum mechanics on the other was almost eerie. It was as if a ghost from psychology past were whispering into the ear of physics present. For once we recognize that classical Newtonian physics does not accurately describe the world and replace it with the quantum physics that does, it emerges naturally and inevitably that the mind has the power to act back on the brain just as James suggested. That makes the notion that mind is strictly determined by the movements of atoms and electrons seem as dated as Newton’s powdered wig.

Classical physics held that the reality of the physical world is constituted of infinitesimal particles in a sea of space. Causation, in this scheme, reflects, at bottom, one particle’s acting on its immediate neighbor, which in turn acts on its neighbor, until—well, until something happens. Wholly deterministic natural laws govern the behavior of matter. Furthermore, reality consists of material objects forever separated, by the chasm of Cartesian dualism, from the immaterial mind. This mechanistic view—stimulus in, behavior
out—evolved into today’s neurobiological model of how the mind works: neurotransmitter in, behavior, thought, or emotion out.

But physics in the years since James had undergone a revolution. The development of quantum physics, in the opening decades of the twentieth century, gave James’s conclusions about the relationship between attention and will a grounding in physical science that they lacked during his lifetime. Although classical physics had failed to validate—had even undermined—James’s theories, it had not had the last word. The very origin of the mind-brain problem lies in a physics that has been outdated for almost a century. Although biologists, as well as many philosophers, cite “the ordinary laws of physics and chemistry” as an explanation for all of the events we gather under the tent labeled “mind,” the laws to which they refer “are a matter of the past,” as the Nobel physicist Eugene Wigner wrote way back in 1969. “[They] were replaced, quite some time ago, by new laws”—the laws of quantum mechanics.

It has been a century since the German physicist Max Planck fired the opening shot in what would become the quantum revolution. On October 19, 1900, he submitted to the Berlin Physical Society a proposal that electromagnetic radiation (visible light, infrared radiation, ultraviolet radiation, and the rest of the electromagnetic spectrum) exists as tiny, indivisible packets of energy rather than as a continuous stream. He later christened these packets
quanta
. Planck, a new professor at the University of Berlin, had no false modesty about the significance of his new radiation formula: he told his son, Erwin, during a walk that day, “Today I have made a discovery as important as that of Newton.” In a lecture to the German Physical Society on December 14, he made his proposal public. Planck viewed his quanta as mere mathematical devices, something he invoked in “an act of desperation” to explain why heated, glowing objects emit the frequencies of energy that they do (an exasperating puzzle known as the
black-body radiation
prob
lem). He did not seriously entertain the possibility that they corresponded to physical entities. It was just that if you treated light and other electromagnetic energy as traveling in quanta, the equations all came out right. But “nobody, including himself, realized that he was opening the door to a completely new theoretical description of nature,” said Anton Zeilinger, one of today’s leading quantum experimentalists, on the one hundredth anniversary of Planck’s talk.

The notion that electromagnetic energy exists as discrete packets of energy rather than a continuous stream became the foundation on which physicists erected what is inarguably the most successful (and strangest) theory in the history of science. The laws of quantum physics not only replicate all the successes of the classical theory they supplanted (that is, a quantum calculation produces an answer at least as accurate as a classical one in problems ranging from the fall of an apple to the flight of a spaceship). They also succeed where the laws of classical physics fail. It is quantum physics, not classical physics, that explains the burning of stars, accounts for the structure of elementary particles, predicts the order of elements in the periodic table, and describes the physics of the newborn universe. Although devised to explain atomic and electromagnetic phenomena, quantum physics has “yielded a deep understanding of chemistry and the solid state,” noted the physicist Daniel Greenberger, a leading quantum theorist: quantum physics spawned quantum technologies, including transistors, lasers, semiconductors, light-emitting diodes, scans, PET scans, and MRI machines. “[T]he extent of the success of quantum theory,” concluded Greenberger, “comes rather as an undeserved gift from the gods.”