The Tell-Tale Brain: A Neuroscientist's Quest for What Makes Us Human

By comparison, the sciences of the mind—psychiatry, neurology, psychology—languished for centuries. Indeed, until the last quarter of the twentieth century, rigorous theories of perception, emotion, cognition, and intelligence were nowhere to be found (one notable exception being color vision). For most of the twentieth century, all we had to offer in the way of explaining human behavior was two theoretical edifices—Freudianism and behaviorism—both of which would be dramatically eclipsed in the 1980s and 1990s, when neuroscience finally managed to advance beyond the Bronze Age. In historical terms that isn’t a very long time. Compared with physics and chemistry, neuroscience is still a young upstart. But progress is progress, and what a period of progress it has been! From genes to cells to circuits to cognition, the depth and breadth of today’s neuroscience—however far short of an eventual Grand Unified Theory it may be—is light-years beyond where it was when I started working in the field. In the last decade we have even seen neuroscience becoming self-confident enough to start offering ideas to disciplines that have traditionally been claimed by the humanities. So we now for instance have neuroeconomics, neuromarketing, neuroarchitecture, neuroarcheology, neurolaw, neuropolitics, neuroesthetics (see Chapters 4 and 8), and even neurotheology. Some of these are just neurohype, but on the whole they are making real and much-needed contributions to many fields.

As heady as our progress has been, we need to stay completely honest with ourselves and acknowledge that we have only discovered a tiny fraction of what there is to know about the human brain. But the modest amount that we have discovered makes for a story more exciting than any Sherlock Holmes novel. I feel certain that as progress continues through the coming decades, the conceptual twists and technological turns we are in for are going to be at least as mind bending, at least as intuition shaking, and as simultaneously humbling and exalting to the human spirit as the conceptual revolutions that upended classical physics a century ago. The adage that fact is stranger than fiction seems to be especially true for the workings of the brain. In this book I hope I can convey at least some of the wonder and awe that my colleagues and I have felt over the years as we have patiently peeled back the layers of the mind-brain mystery. Hopefully it will kindle your interest in what the pioneering neurosurgeon Wilder Penfield called “the organ of destiny” and Woody Allen, in a less reverential mood, referred to as man’s “second favorite organ.”

Overview

Although this book covers a wide spectrum of topics, you will notice a few important themes running through all of them. One is that humans are truly unique and special, not “just” another species of primate. I still find it a little bit surprising that this position needs as much defense as it does—and not just against the ravings of antievolutionists, but against no small number of my colleagues who seem comfortable stating that we are “just apes” in a casual, dismissive tone that seems to revel in our lowliness. I sometimes wonder: Is this perhaps the secular humanists’ version of original sin?

Another common thread is a pervasive evolutionary perspective. It is impossible to understand how the brain works without also understanding how it evolved. As the great biologist Theodosius Dobzhansky said, “Nothing in biology makes sense except in the light of evolution.” This stands in marked contrast to most other reverse-engineering problems. For example when the great English mathematician Alan Turing cracked the code of the Nazis’ Enigma machine—a device used to encrypt secret messages—he didn’t need to know anything about the research and development history of the device. He didn’t need to know anything about the prototypes and earlier product models. All he needed was one working sample of the machine, a notepad, and his own brilliant brain. But in biological systems there is a deep unity between structure, function, and origin. You cannot make very much progress understanding any one of these unless you are also paying close attention to the other two.