The seemingly disparate subjects of computer science, biology, and neuroscience have always fascinated me and, in one way or another, have always influenced my life and career choices. The attentive reader will notice that this book is, mainly, a collage of many ideas about these subjects—ideas I have encountered during the past three decades. The majority of these ideas come from the many talented writers, scientists, and philosophers I have met, sometimes in person but mostly through their works.
The book is somewhat redundant in a way; to understand the topics covered, you could go directly to the original sources. Nonetheless, I believe not many people have walked through life exactly the way I have, and have not had the opportunity I have had to encounter some of these fascinating places, thinkers, and concepts.
I became attracted to math and science early in my life. I always wanted to know how things worked, and studying science looked like an easy way to make a living doing exactly what I wanted to do. As a young boy, I was fascinated by science. I spent years playing with chemistry sets. The concept of a “safe chemistry set” had not yet been invented, and my days were spent concocting new ways to combine chemicals in order to obtain explosive or otherwise dangerous combinations. Flasks, test tubes, beakers, and other chemical apparatus would break, collapse, explode, or simply be made useless by our unguided and exploratory approach to chemistry, but the process provided me and my friends with an endless source of recreation. Furthermore, it looked like science to us.
A few years later, after buying some books and magazines devoted to do-it-yourself electronics, I assembled my first electronic circuits by the blind and laborious process of painstakingly buying individual electronic components and assembling them in accordance with nearly incomprehensible diagrams drawn by people who, unlike me, knew what they were doing.
In the late 1970s, it became possible to acquire a very primitive version of a personal computer. After acquiring a few even more primitive machines, I became the proud owner of a Sinclair ZX Spectrum. The ZX Spectrum, a small personal computer with 48 kilobytes of memory and an integrated keyboard, was a prodigy of the technology at the time. It used a television set as a display. It could be programmed in a dialect of the Basic programming language. It had no permanent memory, and any new program had to be saved to tape on a standard tape recorder. As often as not, depending on the quality of the tape and that of the recorder, I would fail to recover the saved program, but that didn’t deter me from spending my days programming it. Working with the ZX Spectrum was my introduction to programming, and I was hooked on computers for life.
After studying electrical engineering at Técnico in Lisbon, I specialized in digital circuit design, a field that was in its infancy at the time and that developed in close parallel with many other communication and information technologies. In particular, I worked on very-large-scale integration (VLSI) circuits, a general term that is applied to integrated circuits with many devices. Under the auspices of a very influential scientist and politician, José Mariano Gago, Portugal had just signed an agreement with the European Organization for Nuclear Research (CERN). That agreement provided me with an opportunity to spend a summer internship in Geneva. There, at CERN, I tested my programming skills on the equipment that controlled the high-energy particle beams used for experiments in particle physics and was able to share in the unique enthusiasm of the physics community that was searching for the laws that govern the universe. My passion for particle physics was only made stronger by that summer in Geneva.
After my stint at CERN, I felt a need to be closer to the action in the rapidly moving field of digital circuits. I applied to, and was accepted at, the University of California at Berkeley, an institution that excelled in the development of new tools, circuits, and technologies for designing integrated circuits. There I made contact with a whole new world of techniques for designing integrated circuits, many of them developed in the Computer Aided Design (CAD) group then led by Alberto Sangiovanni-Vincentelli (my advisor), Robert Brayton, and Richard Newton. But Berkeley, a school with so many top people in so many fields, made it possible for me to become familiar with a number of other areas that had been relatively unknown to me. Two of these areas fascinated me and defined my future interests: algorithms and neuroscience.
I learned algorithms at Berkeley with Richard Karp, one of the founding fathers of algorithms and complexity theory. Creating algorithms that could be used in designing integrated circuits was the mission of the Berkeley CAD group. Designers of integrated circuits use algorithms to create, verify, simulate, place, and connect the transistors, the working units of all electronic gadgets. Without those complex algorithms, none of today’s integrated circuits could have been designed and fabricated.
At Berkeley, I also had the chance to learn about another field that soon would have many connections with algorithms and computers: neuroscience. I took a minor in neuroscience and managed to learn just enough about evolution, neurons, and brains to squeeze by, but the little I learned was enough to make neuroscience another passion of mine. A number of computer scientists had begun to develop algorithms with which to process biological data, a field that would become later known as bioinformatics. Because of my interests, developing algorithms to address biological problems was an obvious choice for me. Over the years, I was able to make some contributions in that field.
Recently I had an opportunity to review proposals in the scope of the Human Brain Project. The proposals covered many fields, from brain simulation to bioinformatics and brain therapy, and made me more aware of the importance of the connections between the fields. The Human Brain Project aims at using computers to support brain research. In a way, I felt that, with the application of computers to the central problem of understanding the human brain, my trip through science had come full circle.
That trip was influenced by many people. My advisors, colleagues, and students accompanied me, worked with me, and were instrumental in the few relevant scientific results I was able to obtain. The colleagues who worked with me are now spread around the world. My exchanges with them have influenced me in ways that are impossible to describe fully.
However, I believe that the books I read during these decades probably were my greatest influences. Several of them changed the way I saw the world so profoundly that my life would certainly have been very different had I not encountered them. Certainly the book you are reading now would not have been possible were it not for the many authors who, before me, explored the relations between computation, evolution, intelligence, and consciousness.
Although I was influenced by many, a few authors deserve special and explicit mention here. Richard Dawkins and Stephen Jay Gould opened my mind to the wonders of evolution. Daniel Dennett and Douglas Hofstadter steered me toward working in artificial intelligence and developed my interest in the problems of brain, mind, and consciousness. David Hubel described so clearly the way some areas of the brain are organized that one gets the feeling that with a little more effort he could have also explained the behavior of the whole mind. Steven Pinker, Marvin Minsky, and Roger Penrose influenced deeply my own views about the workings of the human mind and the meaning of intelligence, even though I disagree with them in some respects. Kevin Kelly’s ideas on the future of technology and Ray Kurzweil’s unwavering belief in the technological singularity have also been strong influences. James Watson and John Craig Venter provided me with unique insights into how the biological sciences have progressed in the past fifty years. Eric Drexler’s vision of the future of nanotechnology changed my view of the very small and of the world. Sebastian Seung’s, Olaf Sporns’, and Steven Rose’s descriptions of their involvement in projects that aim at understanding the brain were enlightening and inspirational. Nick Bostrom addresses many of the matters covered herein, but develops them further in ways I did not even dream of. Jared Diamond and Yuval Harari changed deeply the way I view human history and human evolution.
Other strong influences come from science fiction, of which I am an avid reader (too avid, some readers will say). Isaac Asimov, Arthur C. Clarke, and Robert Heinlein created in me a lasting interest for science fiction. Greg Egan, Vernor Vinge, Neal Stephenson, Larry Niven, and Charles Stross propose such clear and challenging visions of the future that it becomes easy to believe they will one day happen, strange and perturbing as they are.
I have tried to make this book easy to follow for anyone interested in the topics it addresses. The book is aimed at readers with a general interest in science and technology, and no previous knowledge of any of the many areas covered should be necessary. The final three chapters include no technical material. They present the book’s central argument and can be read independently.
Readers with less technical backgrounds should not be discouraged by the occasional equations, diagrams, and mathematical arguments. I tried to include enough information to help readers grasp some of the technical details, but in most cases the central ideas can be gathered from the accompanying explanations and no significant information will be lost by skipping the details.