If you were shown a picture of a carpenter wielding a hammer and asked to describe the divide between intelligence and tool, you’d maybe say it’s where the hammer meets the hand. Similarly, if shown a picture of a person doing an internet search and asked the same question, some people might describe two divisions: between the hands and the computer’s keyboard, and between the search server and the software that performs operations that could arguably be considered to be intelligent. (People have gone as far as to consider Google the real-life SkyNet.)
In both cases my fictional questionee considered the person’s body to be on the intelligent side, but without too much more consideration it’s clear we need to revise a little. Are skin and bones intelligent? Most would agree no. Muscles? Probably not. Nerves? That’s a more interesting question, but still i’d say we know enough about how they work to be able to describe them as machines that carry out a well-defined task, even if the way in which they do it is fascinatingly complex.
So, where exactly is the boundary of intelligence? At what place can we say, “here be the smarts”? Is it the brain? In the previous paragraph i just said that nerves themselves are just machines – like really complicated hammers, and isn’t the brain just a collection of nerves? (Yes, i know, there’s lots of other stuff in there, but the neurons are still considered to be the most important for intelligence. Also, “nerve” is often just a synonym for a neuron’s axon, and a neuron is much more than that, but i think it’s close enough at the moment for getting the point across.)
But we know that intelligence is in there somewhere. And if the neurons themselves are not intelligent, it must be interaction between the neurons that does the trick. This is why IBM’s cat brain simulation is not so very interesting, but the Blue Brain Project‘s relatively modest effort is. The former is essentially an attempt at scale without realistic interaction, like 10 billion chattering teeth all wound up and set loose at the same time. It makes an impressive spectacle, but really only shows off IBM’s hardware. The latter is a realistic and meticulously detailed simulation of a single cortical column consisting of roughly 20 thousand neurons, from which the scientific findings will likely be enormously important. But, even in all its realism is anything about it intelligent (beyond the brains that it took to create it)? We won’t be able to say for sure until we understand what a cortical column does, but for the reason i explain below i’d suggest the answer is a qualified no.
Going higher up, can we say that a massively interactive system such as the occipital lobe—which takes up roughly a third of the cerebral cortex and is responsible for vision processing—is intelligent? Let me restate the question: would it be of much use on its own? For that matter, would any of the various brain areas be any good on their own? We know from clinical studies that the brain can compensate for the loss of multiple systems, sometimes seemly without negative effect, but that there is a limit. Usually sooner than later there is a noticeable loss of what we consider to be “with it”-ness. (Astute readers will note that an unfortunate person in a “conscious coma” with an intact brain will also fail this test, yet should still be considered intelligent. I’d agree, but suggest that this is failure of the machinery peripheral to the intelligence, not of the argument.)
Getting back to the original question of the boundary of intelligence, we can now see that such a boundary is an abstraction. It exists in function rather than form, and probably at a high level. The brain behaves intelligently through the interaction of its many high level systems. This result leads to many insights about how to recreate an intelligence within a computer – which i will leave to other posts to properly enumerate. For now we can note the following:
- If low-level systems do not manifest intelligence themselves, but rather just inform higher-level systems, it may be possible to abstract the low-level systems in order to simplify the problem. On the other hand, it’s possible—perhaps even likely due to evolutionary conservation—that the functioning of these low-level systems is very similar to how high-level systems work, and that for the most part the difference between the two is merely where they appear in a system hierarchy. My opinion is that there are both significant similarities between levels, and important differences.
- High-level system depend upon each other. Some development efforts currently in progress focus on the functioning of a specific area of the brain. For example, Numenta dedicates their effort entirely to discovering the “cortical algorithm”. (At least, that is the claim made in the book “On Intelligence” by founder Jeff Hawkins. In practice they abstract significantly even from that limited goal, as i determined from an extended discussion with Jeff and lead developer Dileep George.)
- No particular system is necessarily required for intelligence. This may at first appear to be a bold claim, but it’s not really. Skeptics might say that intelligence is impossible without perception, memory, association, pattern organization and recognition, etc. But in fact these attributes are ubiquitous at all levels, right down to the neurons themselves. Some mammalian brain areas such as the hippocampus appear to perform specific memory functions, but referring to it as a memory system is unhelpful; any neuron with plastic synaptic strengths, the ability to form new synaptic connections, and malleable second messenger systems—i.e. every inter-neuron in the brain—is a memory system. Certainly the hippocampus performs functions that aid in the detection, storing and recall of important patterns, but in doing so it is merely doing what every other brain system does: help the organism survive.