Visual Processing and the Immortality of the Soul
Looking around me, what I see is a collection of recognizable objects—a computer screen, a plastic cup half full of diet coke, a telephone and, in my very messy office, a lot of other things. But none of that is in the information feeding from my retinas to my optic nerves. That information consists of a visual field--a flat plane of various colored regions (actually two, one for each eye). Somehow the software in my brain is converting that very uninformative body of data into a reasonably accurate model of the bit of the world I am looking at.
As with many other things the brain does, it only became clear how hard it was when people started trying to write software to duplicate it and discovered that they couldn't—the information coming in was not adequate to generate the information going out. The explanation they came up with was that the brain cheats. In addition to using the information coming in through the retina, it also uses a body of information, generated by some combination of evolution and experience, about what the world is like, information that lets it discard most of the possible explanations of what it gets from the retina in favor of a small number of likely ones.
One such piece of information is persistance of objects. Having recognized the oddly shaped green region to the right of my visual field as the top half of a plastic cup (the bottom half is dark because of the diet coke showing through), my software does not have to redo the analysis three seconds later—even though the region is no longer in the same part of the visual field, my head having turned a little in the meanwhile. Part of the hardwired information is that if the cup was there recently, it is probably still there, or close. Being a rigid object, it is probably still about the same shape, even if a change in the angle at which I am observing it makes it look different.
Some things violate the rules—soap bubbles, for example. That is one of the reasons why soap bubbles seem like odd, almost magical, objects. And there are optical illusions that take advantage of the rules to trick us into seeing what isn't there. But, on the whole, our image processing rules and the software containing them work very well, much better than any software we can ourselves write.
Things persist. People are things, but things of a special sort; when you talk with a friend over the phone it is not his body you are aware of but the person inside. When he dies the body is still there but the person is not—which is intuitively impossible, since the knowledge of the persistence of things is hardwired into your brain.
Which might explain why so many people believe in life after death.