Saturday, September 29, 2012

Through Magic Eyes: How Autostereograms Help us See

Click to enlarge.

An autostereogram is a single-image stereogram (SIS), designed to create the visual illusion of a three-dimensional (3D) scene from a two-dimensional image in the human brain. In order to perceive 3D shapes in these autostereograms, the brain must overcome the normally automatic coordination between focusing and vergence. (Wikipedia)
(But more on autostereograms in a little bit.)

After I stopped believing in God, there was an argument that really bothered me. It was an argument about human rationality, powers of reasoning, and our ability to trust our own thoughts.

The theist, who is raised to distrust human experience, is told to rely on God, and is weary of the 'materialistic' world, has two main types of arguments for and against rationality, which both, oddly enough, try and support the existence of God.

The first one goes like this: Because we have rationality, and can recognize it, means something rational had to create our rational minds.

This is simply a tautology since there is no reason to assume that because we are rational, something rational must have made us. 

This is just circular reasoning, and it actually fails to answer anything, because of a fatal digress. Well, what of the rational mind which created us? What rational thing created it? Theists often will play a semantic game and state: "Nothing created God. God just is."

Well, if that's the case, why can't our cognitive faculty "just be" also? Why make the assumption a rational mind is behidn it in the first place if you're just going to end it with a useless non-starter? Why not skip that step entirely? Well, it's easy to seey why the theist wants to take it in that direction, because they want to leave room for God. But the truth is, God is just an unnecessary ad hoc assumption.

The second argument is a little more difficult to dismiss. It rests on the observation that our cognitive faculties are not without flaw. Than, in fact, we have flawed reasoning.

The idea is, then, if we cannot reason clearly about our experiences then how can we trust anything?

This point was raised by a Christian on my brother-in-blog Mike aka The A-Unicornit's site a while back. His comment shows the sort of thinking behind this styled argument.

"We can never test (and therefore prove) the reliability of our senses because we would need our senses to be reliable in order to do it. Thus, the test would be circular and fallacious. Another crucial "assumption" would be the reliability of our cognitive faculties. These cannot be proven either for the same reasons as our senses."

So, basically, because our reasoning is faulty, we can never prove our reasoning is reliable, therefore we cannot trust our conclusions about any subject. This is why many theists think the naturalistic worldview is an untenable position. In their mind, reasoning, cognition, and the human mind only make sense if it was implanted into us by some divine Creator. But these assumptions ignore many other factors worth considering, all the while positing superfluous supernatural suppositions.

Consider the above autostereogram. It is a jumble of color and seemingly random patterns which intermingle to form a colorful blur. But underneath this chaos of color and form lies a hidden image.

Now this is where things get interesting. Our brains are capable of interpreting the information which our eyes can barely make out. So although there are tons of neuroscience studies that show our cognition is faulty, our brains still have the cognitive power to take an autostereogram, reorganize the information, and make sense of it in the form of a 3D image which isn't really there.

Now, you are probably thinking, what does this have to do with the above argument about cognition? Well, it boils down to this. 

Our eyes can make out the optical illusion, such as the above, which is meant to perplex us. This doesn't mean, however, that we can't see well enough to reliably decipher the image hidden within the autostereogram. In actuality  the above optical illusion proves the theist's argument is fallacious. All it means is that, under certain conditions, the jumble of information the eyes take in gets confused from its journey from eyeball to brain, but our cognitive abilities can, given some proper effort, help make sure we can decode the information.

As one commenter, who raised this same issue over at Mike's blog, stated:

"When we understand and know our cognitive biases we can work around them to get better results. Acknowledging cognitive biases doesn't make our intellect impotent."

Isn't that what it always seems to boil down to? Whether or not we can trust our intellects?

The theist who makes the above argument says, no. Ultimately our cognitive faculties are flawed, and so untrustworthy under a naturalistic paradigm. Therefore the only explanation for working rationality would need to come from a supernatural agent--namely whatever God they want to fill into the gap.

Except for one problem, it's not really a gap.

All they have done is dig themselves a hole, thinking it will buy them some time. But the argument is a non-starter. We simply don't have any good reason to throw out all trust in our eyes, simply because they can be confused by an optical illusion. But allowing the brain enough time to decipher that information, we can see past the illusion. Our senses, and so too our cognitive reasoning, can overcome biases. This proves our cognitive abilities are working well enough to be trusted. So why throw them out?

If you would like to learn more about cognition and the way in which the human brain reasons, I highly suggest reading Michael Shermer's book The Believing Brain for a good introductory piece on this issue. If you want a much more detailed, and technical, book on the subject I suggest you read Self Comes to Mind by Antonio Damasio.


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