Chapter One from "Are You A Machine?
The Brain, the Mind and What It Means To Be Human" by Eliezer Sternberg
In the Scientist's Lair
Suppose that a scientist has mastered the workings of your brain. After years of study, using powerful scanning technology, he has examined every cell, every neural connection and every chemical interaction that exists within your skull. He knows precisely how all these different parts work together. On a giant computer screen, he displays a minutely detailed and extremely accurate digital model of your gray matter. The scientist, however, claims to know more than just the structure of your brain. He declares that he is an expert on how your brain generates thought, how you make decisions and how you behave, even though he has never seen you outside his laboratory. The scientist says that he understands everything about your mind-your memories, doubts, fears, hatreds, cares, sorrows and beliefs-all from studying the structure of your brain.
Do you think that what he claims is possible? The scientist maintains that the brain is an organ like any other. It is a mechanical apparatus just like the heart or the liver or the stomach. "We can understand everything about how those organs function," he says, "so why should the brain be any different?"
If the scientist knows everything there is to know about your brain, would he know what you are thinking at any moment? Would he be able to predict your actions? Would he truly know everything about your mind? Would he know how it feels to have your perspective? Would he know what it is like to be you? If he truly could understand all of this just from studying the mechanisms in your brain, would that make you a machine?
Before we begin to consider this question, we must define what a machine is. The word "machine" is used in a number of ways. Levers and pulleys are called machines, as are cars and motorcycles. Computers and robots are machines, as well as popcorn makers and toaster ovens. The human heart and liver are machines too. A machine can be made of any material. We will consider a machine to be a system of interacting physical parts that operates according to a set of formal rules to accomplish work. So, a lever is a machine because it is a system of parts (a bar and a fulcrum) that interact according to a set of rules: when one side of the bar goes down, the other side goes up. The work the lever performs is lifting one side of the bar (no wonder they call it a "simple" machine), which usually has an object on it. Keep this definition of a machine in mind when considering the questions to come.
Now imagine that the scientist uses his digital model on the computer screen to physically recreate your mind. He first develops silicon chips to duplicate the functions of the neurons in your brain. Meticulously, he reconstructs your neural network, with all its signal pathways intact, using specially manufactured, intricate circuitry. Next, the scientist programs the various parts to operate in precisely the same way that your brain does. He also programs the system with all the knowledge and memories that you possess. If the scientist builds it with structure and operation equivalent to yours, would the machine be you?
The machine processes information in the same way that your brain does and has your physical structure, but would it have your thoughts? Your emotions? Would the machine experience the world the way you do? If so, it would be conscious, but how would you be able to tell? Is there any way to test for consciousness? A robot might tell you all about its inner feelings and its childhood and, when you ask it follow-up questions, it might give satisfactory answers. It might cry when you strike it, grimace when you insult it and yell when you steal from it. Would that make it conscious?
If the scientist could build a machine that is truly conscious, it would mean that consciousness is the product of completely mechanical operations. It might mean that we, too, are machines.
Human consciousness is probably the greatest remaining mystery. As much as we think we know about the brain, nobody has ever figured out how it provides us with consciousness. Most people agree that we could not be conscious without a brain, but exactly how does it make us conscious? How does each of us have an identity? What is the self? Where does free will come from? What exists within us that decides whether to have chicken or fish for dinner, feels pain and love, and views the world with one unified perspective?
Some say that the answer is completely mechanical-that the human mind is merely a computer-like system of signals and responses and is not that different from other natural processes such as digestion or photosynthesis. If this is true, then the scientist may be able to learn everything about your consciousness by studying the structure of the brain that generates it. This could mean that we are machines.
Others believe that consciousness is something separate from the physical world-that no matter how much the scientist may know about your brain, he can never know what you are thinking. The mind is something fundamentally different from physical processes, not merely a mechanical function. Some say that human consciousness is beyond the reach of scientific study altogether. After all, despite many of years of study, nobody yet understands how consciousness is created.
In recent years, because of great leaps in technology and scientific discovery, the age-old study of consciousness has taken new turns. Computers are becoming more and more powerful. Research associated with various psychological disorders is hinting at the operations of some of the systems of the brain. Robots in artificial intelligence labs are accomplishing impressive new feats. Innovative philosophical theories are being proposed. The study of consciousness has become the junction between philosophy, psychology, cognitive science, neuroscience, computer science and engineering. Experts from these fields grapple with new questions of whether a conscious machine could be created and what the implications of such an accomplishment would be for the future of humanity.
Can the scientist understand everything about your mind by studying the structure of your brain? Can he build a conscious machine? What is consciousness, anyway? In the chapters that follow, we will examine the ideas developed by a number of the major players in the controversy over human consciousness as we try to answer the question: Are you a machine?
This book does not focus on consciousness alone, but on how consciousness relates to the question of whether we are machines. If you are interested in the exploring an in-depth philosophical account of consciousness, look for The Rediscovery of the Mind by philosopher John Searle. For a psychological perspective, try In Defense of Human Consciousness by Joseph Rychlak. To learn about the biology of consciousness, read Consciousness by J. Allan Hobson and Consciousness: A User's Guide by Adam Zeman. A good summary of many views on consciousness, meant as an introductory college textbook, can be found in Consciousness: An Introduction by Susan Blackmore.
This concise, lucid primer on neuroscience and philosophy of mind takes the reader to the very depths of the mystery of consciousness, exploring it through the eyes of key philosophers, neuroscientists, and technologists. Avoiding jargon and oversimplification, Eliezer J. Sternberg illuminates baffling questions of the brain, mind, and what it means to be human.
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Last Modified: 9/02/06
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