Human And Artificial Thought

By David Gelernter
Edge, July 2010

Edited by Andy Ross

The net is a complex collection of computers (like brain cells) that are densely interconnected (as brain cells are). It grows at many million points simultaneously, like a living organism. It's only natural to wonder whether the internet will one day start to think for itself.

Computers grow more powerful all the time. Today, programs that are guided not just by calculations but by good guesses are important throughout the software landscape. Computers not only dump huge quantities of information into the cybersphere every day but also help us evaluate this information intelligently.

Thinking is not the same as reasoning. When you look out the window and let your mind wander, you are still thinking. This sort of free association is part of human thought. No computer will be able to think like a man unless it can free-associate.

It is wrong to say that reality is on the outside but your mental landscape is inside your head. Every day we hallucinate when we fall asleep and dream. And when you hallucinate, your own mind redefines reality for you. No computer will be able to think like a man unless it can hallucinate.

The thinker and the thought are inseparable. The computationalist view of the mind is that thinking is viewing a stream of thoughts, so we can replace the human thinker by a computer thinker without stopping the show. But when a person is dreaming or hallucinating, the thinker inhabits his thoughts. No computer will be able to think like a man unless it, too, can disappear into its own mind.

In human thought, the mind moves back and forth along a spectrum defined by ordinary logic at one end and "dream logic" at the other. Dream logic makes just as much sense as ordinary "day logic" but follows different rules. Most philosophers and cognitive scientists see only day logic and ignore dream logic, which is like imagining the earth with a north pole but no south pole.

In a simple, common-sense view of thought, we begin with focus or attention or alertness. We are alert when we are rested and wide awake. As we grow tired, our focus or alertness declines. To solve analytical or mathematical problems, to think acutely or logically, we must be alert. In a state of low alertness, our thoughts tend to move by themselves with no conscious direction from us.

As you come near to falling asleep, you will find thoughts flowing through your mind without conscious guidance. In this state of free association, each new thought resembles or overlaps or somehow connects to the previous thought. As our alertness continues to fall, we lose contact with external reality. Eventually we sleep and dream.

The level of focus or alertness is basic to human thought. Each person's focus moves during the day between maximum and minimum. Your focus is maximum when you are wide awake. It reaches a minimum when you are asleep. This cognitive spectrum is the basic fact of human thought.

Why and how do you lose touch with reality as you fall asleep and dream? Your mind stores memories. Each remembered experience is a potential or alternate reality. Remembering such experiences in the ordinary sense is inspecting the memory from outside. But sometimes remembering means realizing the potential reality trapped in the memory.

Just as thinking works differently at the top and bottom of the cognitive spectrum, remembering works differently too. At the high-focus end, remembering means inspecting the memory. At the low-focus end, remembering means realizing it. When we re-experience memories in dreams, they may be distorted or merged following dream logic.

When your focus is high, you control you thoughts. You confront problems and solve them rationally. As your focus level falls, you begin to lose control of your thinking. Your mind wanders. When you look out a window and let your mind drift, your thoughts take their own course. As your focus level falls still lower, your thought stream moves completely beyond conscious control. And when you fall asleep, your dreams seem to happen without conscious guidance. You experience dreams in nearly the same way you experience external reality.

Losing control of your thought stream equals losing reality. When you sleep and dream, your thoughts are beyond conscious control and reality is gone. Poets and madmen haunt this mental neighborhood.

We all move down the cognitive spectrum every day. But some people are more alive to this experience than others.

Creativity is fascinating. Cognitive psychologists generally agree that creativity happens when a new analogy is invented. Most new analogies lead nowhere, but occasionally they reveal something important. Only when your thoughts have started to drift is creativity possible. We find creative solutions to a problem when it lingers at the back of our minds.

Often, remembered and re-experienced emotions are the key to novel, unexpected analogies. Emotion summarizes experience. Emotion is the music that accompanies life. Just as a snatch of music might bring to mind some long-ago scene, a re-experienced emotion can make us remember a different time and place.

But here the analogy breaks down. A song or phrase might be associated purely by accident with a certain experience. But an emotion is caused by the experience, and summarizes in one feeling an entire, complex scene. An emotion encodes an experience.

Imagine two entities, consciousness and memory. Each corresponds to certain physical structures in the human body. But we are interested in the piano sonata, not the piano. The sonata's structure is a virtual structure. The piano has its own structure. Our topic is the sonata of thought, not the piano of the brain.

We can picture the tidal process of human thought in terms of consciousness and memory. Imagine a small circle inside a bigger one. At maximum focus, memory (the small circle) is wholly contained within consciousness (the large one). Consciousness is surrounded in turn by external reality. You are conscious of memory within you and reality outside you. At minimum focus, consciousness is the small circle, wholly surrounded by memory. Memory comes between consciousness and external reality. You are conscious only of internal, imaginary reality. This is the daily, tidal rhythm of the human mind.

Intelligence can only mean human or human-like intelligence. Some people believe that the internet will develop an entirely new form of intelligence. But this is meaningless. If your new form of intelligence is human-like, it's not new. If it isn't human-like, it's not intelligence.

Human-like intelligence cannot emerge on the internet because the raw materials are wrong. A scientist must assume that consciousness results from a certain structure, just as photosynthesis results from the chemistry of plants. Computers are made of the wrong stuff for photosynthesis and the wrong stuff for consciousness.

Human consciousness and thought emerged from a mechanism that allowed endless, nuanced variations to be tested. Neither condition holds on the internet as we know it.

As far as we know, there is no way to achieve consciousness on a computer or any collection of computers. However, the cognitive spectrum, once we understand its operation and fill in the details, is a guide to the construction of simulated or artificial thought. We can build software models of consciousness and memory, and then set them in rhythmic motion.

The result would be a computer that seems to think. It would be a zombie. But that would make no practical difference. The computer would converse and solve problems just as a man would.

There can be no cognitive spectrum without emotion. Emotion becomes an increasingly important bridge between thoughts as focus drops and re-experiencing replaces recall. Computers have always seemed like good models of the human brain. But emotions are produced by brain and body working together.

One day artificial thought will be achieved. Even then, an artificially intelligent computer will experience nothing and be aware of nothing.

AR  I think this is a good analysis but I disagree with the conclusions. With a focus mechanism, a suitable sensitivity to physical instantiation (for emotions, via feelings, as I argue in my new book G.O.D. Is Great), and some good pico-engineering, nonhuman machines will probably become as experientially aware as we are.