The basic assumption of MDT is that the brain builds and operates models
automatically (this is a hardware function). An exercise is described below
which demonstrates directly this basic assumption.
The absolute majority of beings (human or animal) have two eyes. They generate
two plane images but what we see is a single tri-dimensional image
(photographic-type image model) in accordance with MDT. Moreover, if we have a
single plane image (we look with one eye) the brain will continue to build the
tri-dimensional model.
But we have got a problem: with a single plane image we have not enough
information to build a tri-dimensional image. However we have a
"compensation": the brain is an extremely powerful system. It will use any
kind of supplementary information to build first a tri-dimensional image and
then, the tri-dimensional model. In the following, we will describe an
exercise for beginners to demonstrate this.
We need to watch TV with a single eye in a room with no additional light
source. The glass surface of the screen has to be absolutely invisible (there
should be absolutely no reflection of light on it). We have to sit in front of
a normal screen at least at 3 meters distance (we should not be able to see
the pixels which build up the image). The screen should show a familiar
picture, from common external reality, in normal perspective, and the image
has to change slowly.
If, under these circumstances, we watch the screen with one eye, after some
training, we will see a tri-dimensional image. This experiment proves directly
that the basic function of the brain is to make image models.
The generation of tri-dimensional models by the brain starting from a plane
image is known for a long time. This appeared at the same time with the
expansion of art painting trade, many hundreds of years ago. Thus, a painter
used to paint first the foreground, and later the background. A good painter
had the whole tri-dimensional model in his head, and the background connected
perfectly with the foreground, even if the background was painted a lot later.
In some paintings, the background or some components of the painting do not
match perfectly (a poor painter) and this could be noticed by art experts
looking at the painting with one eye.
Rembrandt painted scenes with groups of people. However, some people in the
group could be "closer" or "farther" from the viewer. When such a compact
group is watched with a single eye, one can notice that the painter had
painted them correctly (the persons farther out are slightly smaller). Our
brain can notice tiny differences, because it reconstructs the 3-D model.
By the way: to build a 3D model based on a single plane image is an operation
which requires an immense capacity of processing of information. In spite of
its huge power, the brain has problems with the capacity of processing such a
huge amount of information. As in principle there is not enough information
for such an operation, the brain has to guess one or several probable models,
which have to be verified. From my direct experience, in order to guess a 3D
model from a plane image ones has to be in a very good physical and psychical
shape.