But the creature we are imagining uses all these abilities to func- tion in the world. Such sophisticated functioning requires integrated guidance and control of disparate body parts and actions—that is, it requires a brain. In humans, the brain is an enormous collection of neurons that controls our behavior along with the sensory and motor functions of our bodies. In an artificial being, the equivalent is an enormous collection of electronic switches—transistors—etched into silicon to make digital microprocessors and memory chips.This type of brain might be all that is needed to steadily make artificial beings more capable because the speed and capacity of silicon chips continue to grow. But other approaches are possible as well: different forms of electronic brains,brains that combine organic and electronic elements, perhaps even actual living brains inserted into cyborgs.
What a brain does is think, and what thinking imparts to a being, natural or artificial, is intelligence.Whether a being with an artificial brain is actually thinking while electrons course through its circuits is still a matter for debate. It is easier to ask,“Is the being intelligent?” because that question can be answered by observing whether it ex- hibits intelligent behavior.Alfred Binet, the French psychologist who in 1905 laid the groundwork for the intelligence quotient (IQ) test, defined human intelligence as the sum of mental processes that come into play in adapting the individual to the environment. Modern defi- nitions agree that intelligence is an adaptive property, meaning that it helps the organism survive and thrive by providing effective responses to changing situations.
This general definition, based on the idea of effective responses to the environment, can also be applied to artificial beings. However, in his book Behavior-Based Robotics, Ronald Arkin takes the definition a step further to make it more explicit for robots. Borrowing his ver- sion and extending it slightly gives this working definition:
An intelligent artificial being is a machine able to extract information from its environment and use knowledge about its world to move, and interact with people, in a safe, meaningful, and purposive manner.
Under this definition, a being that sees its surroundings and interprets them well enough to navigate, and recognizes people and their words