(Copyright © 1999 Piero Scaruffi | Legal restrictions - Termini d'uso )
The Italian neurophysiologist Valentino Braitenberg wrote a book of thought experiments in which the reader is invited to mentally build progressively more complex machines, starting from the most elementary ones.
Braitenberg starts with very simple machines or vehicles that respond to their environment. The first vehicle is simply made of a motor and a sensor: the speed of the motor is controlled by the sensor, motion is meant to be only forward. But in the real world this vehicle is subject to friction (where friction is the metaphysical sum of all forces of the environment) and therefore the trajectory will tend to deviate from the straight line. In fact, in a pond the movement would be quite complex. That's the whole point: despite the simple internal workings of these machines, they seem to be alive. Braitenberg increases little by little their complexity, and at each step they seem to acquire not only new skills, but also a stronger personality. The second vehicle is still fairly simple: two motors and two sensors. The sensor gets excited by whatever kind of matter. It turns out that depending on the way they are wired, they react differently to the exciting matter: one runs towards it, the other one runs away from it. One if "aggressive", one is "afraid". And so forth. As the complexity increases, they seem to exhibit more sophisticated feelings. Always adding simple electro-mechanical components, Braitenberg induces the machines to reason logically (via McCulloch-Pitts neurons). As the devices get more complicated, shapes are recognized; regularities are represented; properties of objects are discriminated. Hebbian associations (that get stronger as they are used) allows for concepts to emerge. Soon the machines start exhibiting learning and memory. Causation (as constant succession) and attention (as self-control over associations) finally lead to trains of thoughts. At this point the human mind can be said to be born and all Braitenberg has to do is add circuitry for social and moral skills.
Of course, all the biological and neurophysiological quantities have only been approximated, but nonetheless those vehicles are very easy to build and do rapidly achieve astonighing levels of pseudo-cognition.
The leitmotiv of the book is the leitmotiv of Braitenberg's research: it is far easier to create machines that exhibit "cognitive" behaviour than it is to analyze their behavior and try to deduce the internal structure that produces such behavior.
Braitenberg's ideas spawned an entire generation of robots, which their constructors appropriately tend to call "creatures".