Life is Like the Tip of an Iceburg. There's More Hidden than Seen.

Powerful Visual Illusions Shed Light on Brain Function

Preamble: Researchers at the University of Pennsylvania have calculated that the human eye can transfer data at the rate of approximately 8.75 megabits per second. Roughly 30% of neurons in the brain’s cortex are devoted to vision, compared with 8% for touch, and 2% for hearing. And, unlike other senses, human vision is processed in the back of the brain in a location called the occipital lobe. Senses of smell, taste, and hearing are processed in the sides of the brain in the temporal lobes.
Beau Lotto is founder of Lottolab, a hybrid art studio and science lab. With glowing, interactive sculpture and old-fashioned peer-reviewed research he’s illuminating the mysteries of the brain’s visual system.

He says context is everything because the light that falls onto your eyes is meaningless – it could be anything. Its what we do with that information that matters.

“Well then how do we see?”, He said.

“We see by learning to see. The brain evolved mechanisms for finding patterns and finding relationships in what we see and associating those relationships with behavioral meaning.”

Here is an example:

Do the top and bottom grey surfaces in the picture below appear different to you? Would it surprise you to learn they are both exactly the same shade of grey?

Are the Top and Bottom Surfaces the  Same shade of Grey?

Here is the same picture again with the area joining the top and bottom surfaces blacked out changing the context.

The lids now look the same.

The Shadow Information is  Blocked Out - Are They the Same Now?

Even though we know both surfaces are the same colour, the contextual information distorts our colour perception of the lower surface.

Here is Another Example:

In the picture below Beau is pointing to two coloured squares on a giant rubix square.

The top square appears to be dark brown while the lower square appears to be light brown or tan.

The rubix cube is evenly lit as can be seen by the light on his legs and arms. However, the front side squares are all dark colours to give the false appearance of being in the shade.

Beau then removes the lower brown square and places it next to the top brown square where we can see that the two squares are both the same colour.

Watch the square change colour in the following capured stills as he moves it up to the top square!



Now watch this fascinating TED talk by Beau Lotto to gain further insight into the way we see.

Beau Lotto: Optical illusions show how we see (16m)
Filmed Jul 2009 • Posted Oct 2009

I Want the LARGER Table!

In the picture below there are two tables in the children’s play room. One table appears longer and thinner than the other, but of course they are exactly the same!

When I first saw this picture I didn’t believe what I was seeing. No way did they look the same, no matter how I looked at it. I printed the image off in black and white and rotated it, trying to look at it from various angles with little success. So then I printed another copy and cut out the long thin tabletop and placed it over the other tabletop. And, hey presto, they were the same!

My brain was being totally fooled!

Pick On Someone Your OWN Size!

In this illusion the boy and girl are the same size and height yet because of the strong perspective lines going off into the distance the girl looks enormous whereas the boy appears tiny.

To our mind, the girl’s head is almost touching the ceiling and her arms can reach out for the walls, however the boy’s head is no where near the ceiling and his arms cannot stretch further than a square on the floor fooling us into believing the girl is a giant and the boy is a migit!

Noted lecturer, cognitive neuroscientist and skeptic, Al Seckel, takes great delight in perceptual illusions and the brain mechanics that they reveal. He is the author of many books, articles, and eye trick calendars. Since leaving Caltech in 2005 to pursue writing and his own research, he has continued his work in spatial imagery with psychology researchers at Harvard. He gave this TED talk in Feb 2004 (posted on the TED site in Apr 2007).

Al says we enjoy having our expectations violated and mostly what we perceive is based on past experience.

Watch this fascinating TED talk by Al Seckel.

Al Seckel: Powerful visual illusions (14m)
Filmed Feb 2004 • Posted Apr 2007

RESOURCES:
TED Talks – Beau Lotto – Optical Illusions Show How We See
Beau Lotto’s Lotto Lab
TED Talks – Al Seckel: Powerful visual illusions
Al Seckel’s Illusionworks
SBS – Test Your Brain You Won’t Believe Your Eyes
National Geographic – Test Your Brain
BBC – The science of optical illusions
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