Incognito (3 page)

If you find space science fascinating, strap in for what’s happening in brain science: we’ve been knocked from our perceived position at the center of ourselves, and a much more splendid universe is coming into focus. In this book we’ll sail into that inner cosmos to investigate the alien life-forms.

Saint Thomas Aquinas (1225–1274) liked to believe that human actions came about from deliberation about what is good. But he couldn’t help noticing all the things we do that have little connection with reasoned consideration—such as hiccuping,
unconsciously tapping a foot to a rhythm, laughing suddenly at a joke, and so on. This was a bit of a sticking point for his theoretical framework, so he relegated all such actions to a category separate from proper human acts “since they do not proceed from the deliberation
of the reason.”
³
In defining this extra category, he planted the first seed of the idea of an unconscious.

No one watered this seed for four hundred years, until the polymath Gottfried Wilhelm Leibniz (1646–1716) proposed that the mind is a melding of accessible and inaccessible parts. As a young man, Leibniz composed three hundred Latin hexameters in one morning. He then went on to invent calculus, the binary number system, several new schools of philosophy, political theories, geological hypotheses, the basis of information technology, an equation for kinetic energy, and the first seeds of the idea for software and hardware separation.
⁴
With all of these ideas pouring out of him, he began to suspect—like Maxwell and Blake and Goethe—that there were perhaps deeper, inaccessible caverns inside him.

Leibniz suggested that there are some
perceptions of which we are not aware, and he called these “petite perceptions.” Animals have unconscious perceptions, he conjectured—so why can’t human beings? Although the logic was speculative, he nonetheless sniffed out that something critical would be left out of the picture if we didn’t assume something like an unconscious. “Insensible perceptions are as important to [the science of the human mind] as insensible corpuscles are to natural science,” he concluded.
⁵
Leibniz went on to suggest there were strivings and tendencies (“appetitions”) of which we are also unconscious but that can nonetheless drive our actions. This was the first significant exposition of unconscious urges, and he conjectured that his idea would be critical to explaining why humans behave as they do.

He enthusiastically jotted this all down in his
New Essays on Human Understanding
, but the book was not published until 1765, almost half a century after his death. The essays clashed with the Enlightenment notion of knowing oneself, and so they languished unappreciated until almost a century later. The seed sat dormant again.

In the meantime, other events were laying the groundwork for
the rise of psychology as an experimental, material science. A Scottish anatomist and theologian named
Charles Bell (1774–1842) discovered that
nerves—the fine radiations from the spinal cord throughout the body—were not all the same, but instead could be divided into two different kinds: motor and sensory. The former carried information out from the command center of the brain, and the latter brought information back. This was the first major discovery of a pattern to the brain’s otherwise mysterious structure, and in the hands of subsequent pioneers this led to a picture of the brain as an organ built with detailed organization instead of shadowy uniformity.

Identifying this sort of logic in an otherwise baffling three-pound block of tissue was highly encouraging, and in 1824 a German philosopher and psychologist named
Johann Friedrich Herbart proposed that
ideas themselves
might be understood in a structured mathematical framework: an idea could be opposed by an opposite idea, thus weakening the original idea and causing it to sink below a threshold of awareness.
⁶
In contrast, ideas that shared a similarity could support each other’s rise into awareness. As a new idea climbed, it pulled other similar ones with it. Herbart coined the term “apperceptive mass” to indicate that an idea becomes conscious not in isolation, but only in assimilation with a complex of other ideas already in consciousness. In this way, Herbart introduced a key concept: there exists a
boundary
between conscious and unconscious thoughts; we become aware of some ideas and not of others.

Against this backdrop, a German physician named
Ernst Heinrich Weber (1795–1878) grew interested in bringing the rigor of physics to the study of the mind. His new field of “
psychophysics” aimed to quantify what people can detect, how fast they can react, and what precisely they perceive.
⁷
For the first time, perceptions began to be measured with scientific rigor, and surprises began to leak out. For example, it seemed obvious that your senses give you an accurate representation of the outside world—but by 1833 a German physiologist named
Johannes Peter Müller (1801–1858)
had noticed something puzzling. If he shone light in the eye, put pressure on the eye, or electrically stimulated the nerves of the eye, all of these led to similar sensations of vision—that is, a sensation of
light
rather than of pressure or electricity. This suggested to him that we are not directly aware of the outside world, but instead only of the signals in the nervous system.
⁸
In other words, when the nervous system tells you that something is “out there”—such as a light—that is what you will believe, irrespective of how the signals get there.

The stage had now been set for people to consider the physical brain as having a relationship with perception. In 1886, years after both Weber and Müller had died, an American named
James McKeen Cattell published a paper entitled “The time taken up by cerebral operations.”
⁹
The punch line of his paper was deceptively simple: how quickly you can react to a question depends on the type of thinking you have to do. If you simply have to respond that you’ve seen a flash or a bang, you can do so quite rapidly (190 milliseconds for flashes and 160 milliseconds for bangs). But if you have to make a choice (“tell me whether you saw a red flash or a green flash”), it takes some tens of milliseconds longer. And if you have to name what you just saw (“I saw a blue flash”), it takes longer still.

Cattell’s simple measurements drew the attention of almost no one on the planet, and yet they were the rumblings of a paradigm shift. With the dawning of the industrial age, intellectuals were thinking about
machines
. Just as people apply the computer metaphor now, the
machine metaphor permeated popular thought then. By this point, the later part of the nineteenth century, advances in biology had comfortably attributed many aspects of behavior to the machinelike operations of the nervous system. Biologists knew that it took time for signals to be processed in the eyes, travel along the axons connecting them to the thalamus, then ride the nerve highways to the cortex, and finally become part of the pattern of processing throughout the brain.

Thinking
, however, continued to be widely considered as
something different. It did not seem to arise from material processes, but instead fell under the special category of the mental (or, often, the spiritual). Cattell’s approach confronted the thinking problem head-on. By leaving the stimuli the same but changing the task (
now make such-and-such type of decision
), he could measure how much longer it took for the decision to get made. That is, he could measure
thinking time
, and he proposed this as a straightforward way to establish a correspondence between the brain and the mind. He wrote that this sort of simple experiment brings “the strongest testimony we have to the complete parallelism of physical and mental phenomena; there is scarcely any doubt but that our determinations measure at once the rate of
change in the brain and of change in consciousness.”
¹⁰

Within the nineteenth-century zeitgeist, the finding that thinking takes time stressed the pillars of the thinking-is-immaterial paradigm. It indicated that thinking, like other aspects of behavior, was not tremendous magic—but instead had a mechanical basis.

Could thinking be equated with the processing done by the nervous system? Could the mind be like a machine? Few people paid meaningful attention to this nascent idea; instead, most continued to intuit that their mental operations appeared immediately at their behest. But for one person, this simple idea changed everything.

At the same time that
Charles Darwin was publishing his revolutionary book
The Origin of Species
, a three-year-old boy from Moravia was moving with his family to Vienna. This boy,
Sigmund Freud, would grow up with a brand-new Darwinian worldview in which man was no different from any other life-form, and the scientific spotlight could be cast on the complex fabric of human behavior.

The young Freud went to medical school, drawn there more by scientific research than clinical application. He specialized in neurology and soon opened a private practice in the treatment of psychological disorders. By carefully examining his patients, Freud came to suspect that the varieties of human behavior were explicable only in terms of unseen mental processes, the machinery running things behind the scenes. Freud noticed that often with these patients there was nothing obvious in their conscious minds driving their behavior, and so, given the new, machinelike view of the brain, he concluded that there must be underlying causes that were hidden from access. In this new view, the mind was not simply equal to the conscious part we familiarly live with; rather it was like an iceberg, the majority of its mass hidden from sight.

This simple idea transformed
psychiatry. Previously, aberrant mental processes were inexplicable unless one attributed them to weak will, demon possession, and so on. Freud insisted on seeking the cause in the physical brain. Because Freud lived many decades before modern brain technologies, his best approach was to gather data from the “outside” of the system: by talking to patients and trying to infer their brain states from their mental states. From this vantage, he paid close attention to the information contained in slips of the tongue, mistakes of the pen, behavioral patterns, and the content of dreams. All of these he hypothesized to be the product of hidden neural mechanisms, machinery to which the subject had no direct access. By examining the behaviors poking above the surface, Freud felt confident that he could get a sense of what was
lurking below.
¹¹
The more he considered the sparkle from the iceberg’s tip, the more he appreciated its depth—and how the hidden mass might explain something about people’s
thoughts, dreams, and urges.

Applying this concept, Freud’s mentor and friend
Josef Breuer developed what appeared to be a successful strategy for helping hysterical patients: ask them to talk, without inhibition, about the earliest occurrences of their symptoms.
¹²
Freud expanded the technique to other neuroses, and suggested that a patient’s buried traumatic experiences could be the hidden basis of their phobias, hysterical paralysis, paranoias, and so on. These problems, he guessed, were hidden from the conscious mind. The solution was to draw them up to the level of consciousness so they could be directly confronted and wrung of their neurosis-causing power. This approach served as the basis for
psychoanalysis for the next century.

While the popularity and details of psychoanalysis have changed quite a bit, Freud’s basic idea provided the first exploration of the way in which hidden states of the brain participate in driving thought and behavior.
Freud and Breuer jointly published their work in 1895, but Breuer grew increasingly disenchanted with Freud’s emphasis on the sexual origins of
unconscious thoughts, and eventually the two parted ways. Freud went on to publish his major exploration of the unconscious,
The Interpretation of Dreams
, in which he analyzed his own emotional crisis and the series of dreams triggered by his father’s death. His self-analysis allowed him to reveal unexpected feelings about his father—for example, that his admiration was mixed with hate and shame. This sense of the vast presence below the surface led him to chew on the question of
free will. He reasoned that if choices and decisions derive from hidden mental processes, then free choice is either an illusion or, at minimum, more tightly constrained than previously considered.

By the middle of the twentieth century, thinkers began to appreciate that we know ourselves very little. We are not at the center
of ourselves, but instead—like the Earth in the Milky Way, and the Milky Way in the universe—far out on a distant edge, hearing little of what is transpiring.