evant and perhaps also even passionate or humorous; or more chal- lenging, make the being capable of initiating and leading a conversa- tion as well as responding to what a human says.
The closer digital beings come to passing the Turing test, the better they will communicate with us, and if language is truly central to thinking, the linguistic ability that satisfies the Turing test might also be necessary for their own self-awareness. But whether or not that inner voice is essential, the human brain remains our only model for the seat of self-awareness, and its most striking feature is its complex interconnectivity. That is shown at the physical level by the convo- luted structure of the brain, which reflects stages in its evolutionary history; at the neuronal level by the multitude of connections be- tween a given nerve cell and others; and at the operational level by the elaborate network of connections and shared functions among subsystems such as the cortex and the limbic system.
This intricate arrangement is distinctly different from the linear pipeline by which computers manipulate data, suggesting that in ad- dition to simulating the brain by programming digital chips, we might need to emulate it by using appropriate hardware, but we cannot emu- late what we do not fully understand. What Marvin Minsky wrote nearly two decades ago in Society of Mind still applies:
Most people still believe that no machine could ever be conscious, or feel ambition, jealousy, humor, or have any other mental life-experience.To be sure, we are still far from being able to create machines that do all the things people do. But this only means that we need better theories about how thinking works.
Because of new techniques such as brain scanning, we know more about the mind than we did then; even so, the unexplored territory is enormous. We strongly suspect, however, that the intricacy of the brain’s internal interactions defines the very fabric of thought and self-perception. As Minsky puts it:“a human intellect depends upon the connections in a tangled web—which simply wouldn’t work at all if it were neatly straightened out.”