|Vehicles: Experiments in Synthetic Psychology|
|summary||Profound, easy to read theories about intelligence in robots.|
Valentino Braitenberg has written one of the cleanest books on robot behavior ever published. It is apparent he wrote exactly what he wanted; no more, no less. The total size of this book is 152 pages, but that seems to be exactly the proper size for the topic he has chosen. Other authors (or editors) would probably say that's not enough pages. It has to be 250, minimum! 400 is better! Not Braitenberg. Vehicles has the raw ideas of a 400-page book. In fact, if you take the proper amount of time to ponder each idea it might even take as long as a 400-page book to get through.
This book contains descriptions of various robots, which Braitenberg calls vehicles since they all use wheels for mobility. They start off simple, then gradually become more complex with each chapter, each new robot being an evolutionary step up from the previous one. In fact, rather than starting with "Chapter 1," Braitenberg starts with "Vehicle 1," and so on. By Vehicle 14 these robots could hardly be said to differ from actual living creatures in the way they behave (though Vehicle 6 describes self-reproducing robots, which is currently beyond our ability to duplicate).
Each new vehicle focuses on an animal behavior: moving, aggression, fear, love and how these can be created in a mechanical vehicle. Braitenberg has a rare mind that can think up original, non-intuitive ideas backed by logic. He also has the ability to present them well. There are a few penalties from Braitenberg's minimalist approach, however. Plain, minimal language can be a bit boring at times, stripping the book of character. Sometimes I like big words and clever turns of phrase that make my mind work, such as the writings of Douglas R. Hofstadter.
How minimal is it? Vehicle 1 contains two pages of text and one page for a diagram. I can just imagine the editor receiving chapter 1 from Braitenberg and saying, "Where's the rest of it?" But it is the perfect length for the simple robot it describes. Vehicle 2 is two pages, plus two pages for two diagrams, and so on. Honestly, for the first four chapters a 12-year-old could read this book and get the same from it as a university professor. His minimalism is admirable, however at times it can feel maddeningly incomplete.
Vehicle 5 (logic) begins by explaining a system of inhibitors that can build a thinking machine. What he is really explaining is the basis for a neural net, however he attempts to do it in five pages. Are five pages enough to explain a neural net? Unfortunately, No. This seemingly simplistic approach actually means he is leaving out vital parts of the explanation that prohibit complete understanding. More description in this chapter would be incredibly helpful. He doesn't talk enough about how the "pulses" given to the neural network gates add up. Is there a cumulative effect going on? After a 1-paragraph explanation he shows 2 examples and describes what they do, but unfortunately he doesn't explain them enough for me to understand the mechanism. Thankfully instances like this are rare, and Vehicle 5 was the only description lacking.
Vehicle 6 describes chance and the role it plays in natural selection. He describes chance as "a source of intelligence that is much more powerful than any engineering mind." Never before have I directly thought of natural selection as being intelligent, but once Braitenberg said it, it sunk in that, Yes, natural selection is intelligent; much more intelligent than any human who ever lived. It is the most skilled engineer ever, making machines of unbelievable complexity and ability. And this "intelligence" has no form, no body. It has always been around since life began and it will always be around until the universe ceases to exist. It is a process; an invisible concept. And yet it is more intelligent than any human.
Artificial Intelligence authors often state the importance of language and symbols, but one can't help but notice that animals seem to do fine without language. And aren't animals intelligent too? He demonstrates that we always assume because an animal reacts a certain way towards an object it must store a symbolic representation of this object. That seems to be reasonable, but Braitenberg demonstrates you can get what appears to be symbolic thought when in fact internally there is no symbol stored -- just electronic paths. It causes one to rethink some well-entrenched ideas about AI. What about meditation? I know when I'm in a meditative state (not thinking/using language) I can perform some actions like sweeping, making food, walking, etc.. So just how important are symbols? Is there a limit to the thoughts that can occur without symbols? I don't think this demolishes the importance of symbols -- likely they are needed to create new ideas -- but they might have their place, one less central than we generally suppose.
At the heart of each vehicle are the pathways that the wires make as they connect sensors to motors. The robots in the first 2 chapters consist of a few sensors, a few motors, and a few wires connecting them. There are no CPUs in any of the robots, except for when the wire connections become so complex, embodying logic, that they effectively become CPUs themselves. The later chapters get into concepts that would not be as easy to replicate in actual robots, and rely a little more on speculation than hard fact. He addresses such difficult topics as getting ideas and having trains of thought. Most of the robots, up to perhaps Vehicle 9 (excluding the evolutionary vehicle) could likely be built in reality. With the recent advent of Lego Mindstorms, the perfect canvas exists to create these types of simple robots, and a programming environment like leJOS Java would make it possible to simulate the wiring described in the book. Maybe someone will eventually recreate the Vehicles in the book using these tools.
The book also includes imaginative artwork of the robots, done in a thought-provoking, abstract style. Unfortunately, rather than interspersing them throughout the book at the appropriate chapter, the editors have placed them all at the end of the book, where they are ineffectual. By the time you get to them, you've either forgotten the thrust of the robot described in the chapter or have mulled over the robot enough already. Having these pictures within each chapter would give the reader something to look at while pondering the meaning of these robots.
So what is this book really about? Well, everyone who reads it probably has his or her own opinion. Braitenberg himself calls it a fantasy with roots in science. I think it is partly about our own origins through evolution, and how something as complex as the human mind might have got started. It's also a bit of a roadmap as to how we might be able to construct our own complex, thinking machines. Braitenberg is laying out no less than the evolution of our brain. For people interested in these topics, he uses his vehicles to construct another metaphor with which to study Darwinian evolution.
Braitenberg includes a section at the end of the book titled "Biological Notes on the Vehicles." These describe the concepts of his robots and how they relate to actual observations in biological creatures. As a scientist, he has done a world of research into brains. I've read his previous book, On the texture of brains: an introduction to neuroanatomy for the cybernetically minded. Though not a popular book, it is evident he is very meticulous in his research. He has dissected and examined fly neurons under microscope for weeks at a time, and from this work, as his mind pondered what he was seeing, came the realizations described in Vehicles. It's quite a treat to read the results of his thoughts without having to do the tedious work yourself! It all adds up to Braitenberg's startling conclusion (which he states at the beginning): The complex behavior we see exhibited by thinking creatures is probably generated by relatively simple mechanisms.
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