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Our future, our universe, and other weighty topics


Friday, May 27, 2016

Saying Your Mind Is Just a Computer Is Like Saying Your Smartphone Is Just a Camera

In Aeon magazine recently there is an essay by psychologist Robert Epstein with the provocative title The Empty Brain. Below the title is an equally provocative essay synopsis:

Your brain does not process information, retrieve knowledge or store memories. In short: your brain is not a computer.

The idea that Epstein is attacking is the doctrine of computationalism, the doctrine that the mind or brain is like a computer, and that the outputs of the mind and brain are like computations. I think Epstein is right to attack this doctrine. But the type of attack Epstein makes on computationalism isn't a terribly skillful one. Some of the points Epstein makes are rather dubious, and he neglects to make some of the best points that can be made against computationalism.

Epstein argues as follows:

Computers really do operate on symbolic representations of the world. They really store and retrieve. They really process. They really have physical memories. They really are guided in everything they do, without exception, by algorithms. Humans, on the other hand, do not – never did, never will. Given this reality, why do so many scientists talk about our mental life as if we were computers?

A small part of this reasoning could be argued through a certain line of reasoning, but not one that Epstein attempts. It can be argued that our memories are not actually stored physically in our brains, that somehow memory involves some larger unknown, on the grounds that we have no understanding of how neurons can store memories. Some of the other claims, however, seem rather dubious. Humans operate using words, and words are “symbolic representations of the world.” When we memorize facts and then recall those facts (as a student will do when studying for a test), that is a process that can reasonably be described as storing and retrieving, even though we have no idea of exactly how or where those facts are stored, and can't even be sure that they are being stored in the brain itself.

Epstein then argues at some length that humans are not information processors. This line of reasoning seems strange. Imagine you get a phone call from your friend, who tells you he is is stuck downtown because he ran out of money and doesn't have bus fare to return home. You get in your car to meet him downtown to drive him home. The phone call can surely be considered information, and your act of driving downtown as a result of that call can be considered processing the information. So why should we not think that humans are information processors? Similarly, when we simply memorize a fact, that can be considered processing a piece of information.

The best way to attack computationalism is a way that Epstein seems to overlook: look for important aspects or outputs of the human mind that are completely unlike anything produced by computers. The way to refute the “your mind is just a computer” thinkers is not to argue “the mind never computes” but to argue “the mind does so much more than just compute.” So let us ask: what outputs does the human mind have that are not produced to any extent at all by computers?

The first output I can think of is understanding. Humans have this, but computers do not. The most expensive supercomputer ever produced has never had the slightest understanding of anything. Given certain prompts, a computer can retrieve relevant information. But it understands nothing.

Let us imagine American foreign-exchange students working at a big library in China, Americans who cannot understand spoken or written Chinese. Let us suppose that people come to an information desk of the library, with questions and information requests written in Chinese on slips of paper. Imagine that the American library workers cannot understand any of the questions, but have worked out a system by which certain information sheets or books (all in Chinese) will be given to those who have certain Chinese words (or series of words) on their information request slips. This is rather how a computer works. When you do a Google search for “United States,” some computer server at Google may be able to figure out that certain information items are to be sent back to you in response to this request. But that computer has not the slightest understanding of any of these information items, nor does it have the slightest understanding of what the United States is.

And so it basically is for all computer processing. Every single time you ask a computer for information, it is completely lacking in understanding of what you asked and what the outputs are that it gave back to you. When you ask your computer what was the birth date of President Abraham Lincoln, it may very quickly respond: February 12, 1809. But your computer has not the slightest understanding of what a president is, what a birth date is, what any date is, who Abraham Lincoln was, or what a person is. What you see in this case is a correlation between a fact and the computer response. But we should not confuse a correlation with cognition.

Computers have not an iota of understanding. This is one major reason why we should not be comparing the human mind to a computer. Another gigantic reason is that probably the essential output of the human mind is what we might variously call consciousness, experience, or life-flow: a stream of experiences of the type someone has when that person is consciously living a particular day. We can define life-flow as the stream of thoughts, feelings, and sensations that go on while you are awake, but which temporarily stop while you are sleeping. Such life-flow is the most essential output of the human mind. But computers have no such output. No computer has ever had the slightest bit of life-flow. It's futile to try to ask ourselves what it is like to be a computer, because computers have not the slightest bit of life-flow.

So because it provides understanding and life-flow (also called experience), the human mind is something vastly more than just a computer (which has no such things as its output). Calling the human mind or brain a computer is like calling your smartphone a camera. Your smartphone includes a not-very-good camera, but it has vastly more (also allowing you to call people, run apps, play games, and browse the internet). Similarly it's rather as if the human mind has a not-very-good computer inside it, but its main outputs are things (understanding and life-flow) that are totally different from computer outputs.

Although Epstein seems to err in trying to completely deny a computation aspect of the human mind, he is correct in suggesting the futility of all attempts to explain the human mind in a mechanical kind of way.