The Future of the Mind (11 page)

THE MYSTERY OF SELF-AWARENESS

If the space-time theory of consciousness is correct, then it also gives us a rigorous definition of self-awareness. Instead of vague, circular references, we should be able to give a definition that is testable and useful. We’ll define self-awareness as follows:

Self-awareness is creating a model of the world and simulating the future in which you appear
.

Animals therefore have some self-awareness, since they have to know where they are located if they are going to survive and mate, but it is limited largely by instinct.

When most animals are placed in front of a mirror, they either ignore it or attack it, not realizing that it is an image of themselves. (This is called the “mirror test,” which goes all the way back to Darwin.) However, animals like elephants, the great apes, bottlenose dolphins, orcas, and European magpies can figure out that the image they see in the mirror represents themselves.

Humans, however, take a giant step forward and constantly run future simulations in which we appear as a principal actor. We constantly imagine ourselves faced with different situations—going on a date, applying for a job, changing careers—none of which is determined by instinct. It is extremely difficult to stop your brain from simulating the future, though
elaborate methods have been devised (for instance, meditation) to attempt to do so.

Daydreaming, as an example, consists largely of our acting out different possible futures to attain a goal. Since we pride ourselves in knowing our limitations and strengths, it is not hard to put ourselves inside the model and hit the “play” button so we begin to act out hypothetical scenarios, like being an actor in a virtual play.

WHERE AM “I”?

There is probably a specific part of the brain whose job it is to unify the signals from the two hemispheres to create a smooth, coherent sense of self. Dr. Todd Heatherton, a psychologist at Dartmouth College, believes that this region is located within the prefrontal cortex, in what is called the medial prefrontal cortex.
Biologist Dr. Carl Zimmer writes, “The medial prefrontal cortex may play the same role for the self as the hippocampus plays in memory … [it] could be continually stitching together a sense of who we are.” In other words, this may be the gateway to the concept of “I,” the central region of the brain that fuses, integrates, and concocts a unified narrative of who we are. (This does not mean, however, that the medial prefrontal cortext is the homunculus sitting in our brain that controls everything.)

If this theory is true, then the resting brain, when we are idly daydreaming about our friends and ourselves, should be more active than normal, even when other parts of the brain’s sensory regions are quiet. In fact, brain scans bear this out. Dr. Heatherton concludes, “
Most of the time we daydream—we think about something that happened to us or what we think about other people. All this involves self-reflection.”

The space-time theory says that consciousness is cobbled together from many subunits of the brain, each competing with the others to create a model of the world, and yet our consciousness feels smooth and continuous. How can this be, when we all have the feeling that our “self” is uninterrupted and always in charge?

In the previous chapter, we met the plight of split-brain patients, who sometimes struggle with alien hands that literally have a mind of their own. It does appear that there are two centers of consciousness living within the same brain. So how does all this create the sense that we have a unified, cohesive “self” existing within our brains?

I asked one person who may have the answer: Dr. Michael Gazzaniga, who has spent several decades studying the strange behavior of split-brain patients. He noticed that the left brain of split-brain patients, when confronted with the fact that there seem to be two separate centers of consciousness residing in the same skull, would simply make up strange explanations, no matter how silly. He told me that, when presented with an obvious paradox, the left brain will “confabulate” an answer to explain inconvenient facts. Dr. Gazzaniga believes that this gives us the false sense that we are unified and whole. He calls the left brain the “interpreter,” which is constantly thinking up ideas to paper over inconsistencies and gaps in our consciousness.

For example, in one experiment, he flashed the word “red” to just the left brain of a patient, and the word “banana” to just the right brain. (Notice that the dominant left brain therefore does not know about the banana.) Then the subject was asked to pick up a pen with his left hand (which is governed by the right brain) and draw a picture. Naturally he drew a picture of a banana. Remember that the right brain could do this, because it had seen the banana, but the left brain had no clue that the banana had been flashed to the right brain.

Then he was asked why he had drawn the banana. Because only the left brain controls speech, and because the left brain did not know anything about a banana, the patient should have said, “I don’t know.” Instead he said, “It is easiest to draw with this hand because this hand can pull down easier.” Dr. Gazzaniga noted that the left brain was trying to find some excuse for this inconvenient fact, even though the patient was clueless about why his right hand drew the banana.

Dr. Gazzaniga concludes, “
It is the left hemisphere that engages in the human tendency to find order in chaos, that tries to fit everything into a story and put it into a context. It seems that it is driven to hypothesize about the structure of the world even in the face of evidence that no pattern exists.”

This is where our sense of a unified “self” comes from. Although consciousness is a patchwork of competing and often contradictory tendencies, the left brain ignores inconsistencies and papers over obvious gaps in order to give us a smooth sense of a single “I.” In other words, the left brain is constantly making excuses, some of them harebrained and preposterous, to make sense of the world. It is constantly asking “Why?” and dreaming up excuses even if the question has no answer.

(There is probably an evolutionary reason that we evolved our split
brains. A seasoned CEO will often encourage his aides to take opposing sides of an issue, to encourage thorough and thoughtful debate. Oftentimes, the correct view emerges out of intense interaction with incorrect ideas. Similarly, the two halves of the brain complement each other, offering pessimistic/optimistic or analytical/holistic analysis of the same idea. The two halves of the brain therefore play off each other. Indeed, as we shall see, certain forms of mental illness may arise when this interplay between the two brains goes awry.)

Now that we have a working theory of consciousness, the time has come to utilize it to understand how neuroscience will evolve in the future. There is a vast and remarkable set of experiments now being done in neuroscience that are fundamentally altering the entire scientific landscape. Using the power of electromagnetism, scientists can now probe people’s thoughts, send telepathic messages, telekinetically control objects around us, record memories, and perhaps enhance our intelligence.

Perhaps the most immediate and practical application of this new technology is something once considered to be hopelessly impossible: telepathy.

The brain, like it or not, is a machine. Scientists have come to that conclusion, not because they are mechanistic killjoys, but because they have amassed evidence that every aspect of consciousness can be tied to the brain.

—STEVEN PINKER

3
TELEPATHY A PENNY FOR YOUR THOUGHTS

Harry Houdini, some historians believe, was the greatest magician who ever lived. His breathtaking escapes from locked, sealed chambers and death-defying stunts left audiences gasping. He could make people disappear and then reemerge in the most unexpected places. And he could read people’s minds.

Or at least it seemed that way.

Houdini took pains to explain that everything he did was an illusion, a series of clever sleight-of-hand tricks. Mind reading, he would remind people, was impossible. He was so outraged that unscrupulous magicians would cheat wealthy patrons by performing cheap parlor tricks and séances that he even went around the country exposing fakes by pledging he could duplicate any feat of mind reading performed by these charlatans. He was even on a committee organized by
Scientific American
that offered a generous reward to anyone who could positively prove they had psychic power. (No one ever picked up the reward.)

Houdini believed that telepathy was impossible. But science is proving Houdini wrong.

Telepathy is now the subject of intense research at universities around
the world, where scientists have already been able to use advanced sensors to read individual words, images, and thoughts in a person’s brain. This could alter the way we communicate with stroke and accident victims who are “locked in” their bodies, unable to articulate their thoughts except through blinks. But that’s just the start. Telepathy might also radically change the way we interact with computers and the outside world.

Indeed, in a recent “Next 5 in 5 Forecast,” which predicts five revolutionary developments in the next five years, IBM scientists claimed that we will be able to mentally communicate with computers, perhaps replacing the mouse and voice commands. This means using the power of the mind to call people on the phone, pay credit card bills, drive cars, make appointments, create beautiful symphonies and works of art, etc. The possibilities are endless, and it seems that everyone—from computer giants, educators, video game companies, and music studios to the Pentagon—is converging on this technology.

True telepathy, found in science-fiction and fantasy novels, is not possible without outside assistance. As we know, the brain is electrical. In general, anytime an electron is accelerated, it gives off electromagnetic radiation. The same holds true for electrons oscillating inside the brain, which broadcasts radio waves. But these signals are too faint to be detected by others, and even if we could perceive these radio waves, it would be difficult to make sense of them. Evolution has not given us the ability to decipher this collection of random radio signals, but computers can. Scientists have been able to get crude approximations of a person’s thoughts using EEG scans. Subjects would put on a helmet with EEG sensors and concentrate on certain pictures—say, the image of a car. The EEG signals were then recorded for each image and eventually a rudimentary dictionary of thought was created, with a one-to-one correspondence between a person’s thoughts and the EEG image. Then, when a person was shown a picture of another car, the computer would recognize the EEG pattern as being from a car.

The advantage of EEG sensors is that they are noninvasive and quick. You simply put a helmet containing many electrodes onto the surface of the brain and the EEG can rapidly identify signals that change every millisecond. But the problem with EEG sensors, as we have seen, is that electromagnetic waves deteriorate as they pass through the skull, and it is difficult to locate their precise source. This method can tell if you are thinking of a car or a
house, but it cannot re-create an image of the car. That is where Dr. Jack Gallant’s work comes in.

VIDEOS OF THE MIND

The epicenter for much of this research is the University of California at Berkeley, where I received my own Ph.D. in theoretical physics years ago.
I had the pleasure of touring the laboratory of Dr. Gallant, whose group has accomplished a feat once considered to be impossible: videotaping people’s thoughts. “
This is a major leap forward reconstructing internal imagery. We are opening a window into the movies in our mind,” says Gallant.

When I visited his laboratory, the first thing I noticed was the team of young, eager postdoctoral and graduate students huddled in front of their computer screens, looking intently at video images that were reconstructed from someone’s brain scan. Talking to Gallant’s team, you feel as though you are witnessing scientific history in the making.

Gallant explained to me that first the subject lies flat on a stretcher, which is slowly inserted headfirst into a huge, state-of-the-art MRI machine, costing upward of $3 million. The subject is then shown several movie clips (such as movie trailers readily available on YouTube). To accumulate enough data, the subject has to sit motionless for hours watching these clips, a truly arduous task. I asked one of the postdocs, Dr. Shinji Nishimoto, how they found volunteers who were willing to lie still for hours on end with only fragments of video footage to occupy the time. He said the people in the room, the grad students and postdocs, volunteered to be guinea pigs for their own research.

As the subject watches the movies, the MRI machine creates a 3-D image of the blood flow within the brain. The MRI image looks like a vast collection of thirty thousand dots, or voxels. Each voxel represents a pinpoint of neural energy, and the color of the dot corresponds to the intensity of the signal and blood flow. Red dots represent points of large neural activity, while blue dots represent points of less activity. (The final image looks very much like thousands of Christmas lights in the shape of the brain. Immediately you can see that the brain is concentrating most of its mental energy in the visual cortex, which is located at the back of the brain, while watching these videos.)