excreationist

I just wanted to see how effective this argument was.


As you can see, there appear to be some flickering black dots there, except in reality there aren't any black dots there...

So it looks like God (assuming he exists) gave us a visual system with some bugs (quirks/problems) in it. Or is this somehow an example of something that obviously was *perfectly* designed?

(BTW, what do you call Intelligent Design advocates? ID-ists? IDers?)

Oolon Colluphid

IDiots.

Ref the dots, I'm not sure you could call it a flaw, but the visual cortex here clearly doesn't work as well as it should, if the aim of vision is to accurately model the outside world.

Oolon

notto

ID-iots?

Sorry, too easy!

Sojourner553

Cool picture!!!!!!


Here is some of the theory that goes with your picture:

THE HUMAN EYE- It is true that the eye performs magnificently as a
camera. Yet, it is NOT a "perfect" design. Indeed The blind spot that occurs in
human's vision is due to the fact that the photoreceptor cells in our retina are
"wired in backwards". This means the nerves from the retina are in FRONT OF and
alongside of the source light--instead of leading AWAY from the light. This
design SCREENS out some of the incoming light, and requires the nerves to
travel over the photoreceptor cells on the surface of the retina, to a hole in
the back of the retina itself--creating a BLIND SPOT.

Our brain compensates for this blind spot and gives us the sensation of a
uniform range of vision. However objects that fall in line with the blind
spot are just not seen. Not all creatures have this design problem. The squid
is heralded by scientists to have the most beautifully constructed eyes. Among
other features, the nerves in squids are situated leading BEHIND the
photoreceptor cells.

--------------------------------

Actually -- I thought this was more powerful evidence for evolution:

As the Genome Project has confirmed (which has completed a
massive computerized genetic database of all the base pairs of DNA in human
chromosomes), only about 2-5 percent of human DNA is believed to be composed
of genes. (Genes contain the instructions to make proteins). The rest of the 95-
98% of genetic material is regulatory sequences, old nonfunctioning genes or
most common of all: non-coding "junk". Bob Waterson, Director of the Genome
Center at Washington University in the U.S. explained it this way:

"the distribution of genes on mammalian chromosomes is uneven, making
for a striking appearance . . . in some regions, genes are crowded
together much like buildings in urban centers. In other areas, genes
are spread over the vast expanses like farmhouses on the prairie.
And then there are large tracts of desert, where only non-coding
'junk DNA' can be found. Each region tells a unique story about the
history of our species and what makes us tick."

Sometimes the genes are not contiguous - but stop and start amid junk
genetic base pair sequences between them (creating a challenge to detect them at
all even using super computers.) Even more interestingly: Large stretches of
the human genome show sections that look as if viruses were incorporated into
them-- probably millions of years ago through infections. Hundreds of genes
(encoding at least 223 proteins) appear to be identical to those of bacteria. It
has been estimated that roughly 50% of the number of genes in humans is
identical to those in yeast. (Henry Gee, "A Journey into the Genome: What's
There", Nature News Service/Macmillan Magazine LTD. February 12, 2001)

Do not wish to be associated w/ II

I think the optical illusion above works because of lateral inhibition- where adjacent neurons inhibit each other's activity. I don't think it has anything to do with the blind spot per se.

excreationist

Here it is with red squares:


I finally found out more information about it... it is called "the Scintillating Grid".

<a href="http://www.unm.edu/~toolson/435scint.html" target="_blank">An interactive version</a>

<a href="http://www.perceptionweb.com/ecvp97/64mon.html" target="_blank">A 1997 study about it</a> - this just describes the effect I think.

from <a href="http://www.google.com/search?q=cache:ulqNncDIs4oC:www.illusionworks.com/html/scintillating_grid.html+hermann*+grid&hl=en" target="_blank">google cache - IllusionWorks</a>:
It works if you print it out too... (my Mum thought that the computer was making it change rather than her eyes )
You need to print it out in fairly good quality though so the black is black and the gray is gray. And the white looks much whiter if you have it in the sun.

[ March 27, 2002: Message edited by: excreationist ]</p>

tronvillain

Sojourner553: Having two eyes with overlapping fields of vision makes our blind spots largely unimportant. Now, it's not clear that what the brain does is accurately described as "compensation" for the blind spot - the brain has evolved around the blind spot, and we may have a "uniform field of vision" because no part of the brain is expecting input from that region of the retina.

excreationist

I've been experimenting with the picture and ways of looking at it and it looks like the effect is much less extreme and sometimes not noticeable if you only look at it with one eye rather than two. Especially if you are relaxed.

The area you are looking directly at is seen properly, while the rest can be "seen" incorrectly. I think this may be image compression and then the colour and shape recognition is done later. (I think we are only directly aware of high level features like lighting, shapes, colours and what it "is" - not gigabytes of raw pixel data per second)

I think the effect is much more noticeable when you're not relaxed is because your eyes are very curious - darting around, looking for excitement. It seems that this effect happens when your eyes only get an extremely brief direct look at an area. I mean usually when we are looking at something, our eyes dart around very fast, mapping out the features of the scene. I think not much information is actually coming into our short-term memory - but since our eyes are moving so much it appears like the scene is extremely high resolution. If we keep our eyes still only the area directly in front of them is in focus - the rest is a blur. I guess the effect in the periphery is probably something like "lateral inhibition" though, even though the quote earlier said that it wasn't. But I think this "lateral inhibition" mostly only happens with the sight neurons that aren't in the centre of the rentina.

This is the Hermann Grid Illusion:

In that picture the intersections are white if you focus on them directly, part go darker if you look around at other things. Usually the textbooks would say that it all just goes dark. And using one eye makes it much easier to focus on one area.

I don't really have a theory why two eyes would make the effect so much worse though - maybe they scan around partly independently and there is more movement going on - as I said, it looks like it takes time to bring an area into focus and to see it properly.

In the coming days I hope to print a really psychelic iron-on t-shirt transfer which has lots of white dots with the black squares and gray dots.

Hopefully an ID-ist or a creationist will respond sometime...

excreationist

So far, not one creationist or supporter of the intelligent design theory has responded!

I have also posted this topic at the Christian hip-hop band, <a href="http://bbs.payableondeath.com/ubb/ultimatebb.php?ubb=get_topic;f=2;t=004342" target="_blank">P.O.D.'s forum</a>. Many Christians had a go at defending their faith there.

I wonder why this hasn't happened here? Could it be... that our visual system is flawed?

ex-robot

I say everyone get drunk and assume that there was a fall/curse and ask has our visual system deteriorated over time since then.

xr