Showing posts with label The Blind Spot. Show all posts
Showing posts with label The Blind Spot. Show all posts

Thursday, 14 May 2009

My theory suggests that there is something not quite right with the "common-sense" approach to reality. When I discuss these issues with the public I find that most people assume that the world "out there" is exactly as their senses tell them it is. A classic example of this was the heated debate on this very subject that took place on the Graham Hancock site in April. it is clear to me that for many there is no mystery and that I am somehow a little bit crazy in the way I evaluate consciousness and its interaction with reality.

However I suggest that it is common-sense that is in error and that the masses are deluding themselves in their enthusiasm to remain in their "comfort zone". Indeed I find that sometimes people can become quite aggressive when I suggest that they reflect back on themselves and for a second or two evaluate the real nature of consciousness and perception.

An example of this is that a few days ago I was in discussion with my optician. He was testing my eyesight with all his latest equipment and in the course of our conversation I brought up the question of the "blind spot" in our field of vision. There is a blind spot in each eye where there are no photoreceptors. This is because there has to be a place where the optic nerve is positioned. We don't usually notice the blind spot. However it is always there. I mentioned to the optician that I thought it odd that the brain seems to "fill in the missing section of vision". The optician disagreed with me and said that there was no mystery at all. He explained that we do not notice it for one simple reason; what falls on the blind spot of one eye does not fall on the blind spot of the other. He added that because the eyes are in constant motion so that what falls on the blind spot now does not fall on it a second later. For him that was the simple answer.
This was a typical response of a professional who was dealing with an enthusiastic layperson. I was wrong in my assumption and his opinion was correct. There is no mystery. However there is, a huge one, and one that I guess either he was not aware of or simply wishes to ignore it because it simply does not fit in with the present scientific paradigm. I could have mentioned this to him but decided against it. After all, what would be the point?

So why am I so sure that he is wrong? Well, try this experiment. Keep your head very still and stare at a blank surface such as a wall. Close one eye. Now there will be no overlap of the fields of vision so one eye will not compensate for the other (the optician's central argument). As you are not moving your head there is also no overlap of monocular vision as your single eye stares straight ahead. But still there is no blind spot! In fact it is quite difficult to demonstrate the blind spot and this involves staring at an object with one eye open at a specific distance. So for me there can only be two conclusions to be made about the opticians response - either he knew that the mystery did exist and pretended it didn't or he was simply unaware that the "received wisdom" was wrong.

And this really is a huge mystery because it implies that the brain, not the eye, fills in the missing information. But what is weird is that it fills in the information so seamlessly that we do not notice it. We are fooled into believing that we have an unbroken field of vision.
The philosopher-scientist Daniel Dennett argues that the information is not "filled in" but it is simply ignored. But this does not make the process any stranger. This suggests that the brain can manipulate or field of vision to the extent that areas are "ignored". This still implies that what we actually perceive is not what the eyes actually "see".

Indeed the above is somewhat of an understatement. Again most people assume that what is focused on the back of the eye is what is "seen" in the brain. They are taught that the retina simply acts like role of film at the back of a camera. The light comes in through the lens, the photons/waves (see my recent postings on this additional mystery below) then land on the light sensitive film and an image is created. This photograph is then sent to the brain and "presented" to consciousness. However this "snapshot" analogy is totally inadequate.

The amount of visual information that lands on the retina is extremely limited. There are two retinal images, not one, and they are are distorted, tiny and upside down. In addition the resolving power of the eye is limited and non-uniform. Indeed outside of the high resolution foveal region, the retina is nearly colour-blind and its powers of descrimination are severely limited. On top of this, as the optician rightly pointed out to me, the eye is in nearly constant motion. This movement is called saccadic motion and involves the eye changing position three or four times a second. As a result of this the actual image that lands on the retina takes the form of a succession of of alternating snapshots and grey-outs.

The perception philosopher, Professor Alvin Noe of the University of California, does not share the comfortable world of the "guy down the pub" about the nature of visual perception and its implications for the ultimate nature of reality. In an essay called “Is The Visual World a Grand Illusion?” In a book of the same title, Professor Noe writes the following in relation to the mystery of who the brain "creates" a stable and enveloping visual experience from such limited data:

“How, on the basis of this fragmented and discontinuous information, are we able to enjoy the impression of seamless consciousness of an environment that is detailed, continuous, complex and high resolution? This is the problem faced by visual theory.”

ITLAD/CTF and Karl L LeMarcs' CtCw attempt to explain these anomalies of perception (and those of particle physics) in a totally new paradigm ... an uber-theory... collectively known as BIGTOE. We do seem to have a workable theory that can explain many, if not all, of these "Black Swans" that so irritate and annoy those, such as my optician, who pretend that they have all the answers and there are no problems with the present paradigm.

Rather reminds me of the position of scientists such as Ernest Mach at the turn of the 19th/ 20th centuries. For me these curiosities are the "photo-electric effect" and the "black body radiation" of the 21st century. They have to be explained in order for us to advance our understanding of consciousness and its relationship with the Phenomenal World.