May 24, 2010

Seeing Isn't Believing

This is a bit of a dedication to the previous color scheme I was using and the after images some of those previous readers experienced after reading some of my longer posts. In this post I will show some optical illusions, which are always fun to see, talk about what the human brain actually gets from the eyes, and then talk about some of the ramifications.

Those people who were unlucky enough to see my blog in its past format can stare at the picture on the right for 30 or so seconds and then look away to a white or soft colored background. This is because your retina will adapt to the unchanging stimulus and actually stop responding to it. So people who were reading my white text on the black background were inadvertently 'looking at the x', and then seeing waves of text as after images. It then takes a little while for it to start adjusting again. I got this information and picture from the sampling of Illusions page, which I found linked from Scientific American.

The winner of the the best illusion from this year actually has relevance to my home country of Canada. The winner showed how from one perspective it looks like balls are rolling up hill. This is something found in Moncton, New Brunswick in a place that is referred to as Magnetic Hill. It is called Magnetic Hill, because that was how some people explained how the cars could be 'pulled' uphill. There is even a wikipedia page on it and About has an article that shows nearly a dozen places in the US that are like it.

It is actually surprising that the brain isn't tricked by optical illusions more often  Ray Kurzweil does a great job in The Singularity is Near (pages 185 -188) pointing out some information that I will summarize here, but if you don't have the book you can find nearly the same information here. It really points out that the process of vision is a collection of stimulus, then the cortex makes guess about what it is seeing and tries to match it up with something. There is an illusion that the eyes are sending high resolution pictures, but what is really being sent is 10-12 output channels, each carrying minimal information. One group looks for the changes in contrast, another looks for uniformity in color, while another constraints solely on the background of what is of central attention. Kurzweil goes as far to say that, "[After getting those 10-12 pictures from the brain] We then essentially hallucinate the world from cortical memories that interpret a series of extremely low-resolution movies that arrive in parallel channels. There is a picture in the book that gives a general idea of what the eye see's but for the life of me I couldn't find it on the internet.

Anyway given the lack of actual information and how the brain makes up for it, and the beliefs of people I am actually surprised more ghosts and flying saucers aren't seen. Pareidolia, can be seen in how people can see what they are looking for in random visual information, and is a source of money for those who can make a Jesus like object appear on anything.  

I recently experienced some pareidolia myself. When I am fishing I am constantly looking for fish in the water, and I looked beside the boat and saw what I thought to be a huge fish. I was startled then realized that the fish wasn't moving and that it was instead a rock, but I was tricked for a few seconds.

There is no shame in being tricked, and when people are looking for a specific thing they will find it eventually. There will be stimulus that the mind will link to that thing. People are great a picking out patterns in clouds, the real skill comes in after the image is seen and distinguishing the meaning of these patterns.

Thanks for reading,
The Moral Skeptic

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