Friday TED Talk: Al Seckel on our Crossed Visual Circuits

Al Seckel, a cognitive neuroscientist at Cal Tech, gives a talk in which he illustrates how easy it is to fool the visual circuitry in our brains when you know how. I reproduce below the video of his talk at the February 2004 TED Conference, but this is one talk you really need to watch in the high-resolution (MP4) version (QuickTime or Windows Media Player required) --- you will pick up a lot more of the visual detail:

You can read more about Al Seckel and his work here, and you can download versions of his talk from this page.

Now here is another Seckel-type illusion to fool your eyes:

You will be unable to tell it no matter how long you stare at the image, but the fact is (as you can see by looking closely at the center of the image, where the "blue" and the "green" spirals merge) that the two spirals --- one appearing to be "green" and the other "blue" --- are exactly the same color. Our brain, however, sees the orange stripes running through the former, but not the latter (which has magenta stripes), and is wired to register the one combination as "green on orange", while the other is "blue on magenta".

More on the above illusion may be found at this link.; the reference site (slow-loading) is here.