Is seeing believing? BBC Horizon looks at sensory perception, illusions and the interplay of our different senses. (Full program for UK viewers here). Makes you feel like you've entered The Twilight Zone. [more inside]
posted by philipy on Oct 18, 2010 - 16 comments

More good stuff for people who like visual ("optical") illusions (previously): A nice Scientific American article, a particularly creepy illusion, and a link to the "Best visual illusion of the year" contest. Given that the eye/mind/brain is so easy to trick, a person might wonder what's really out there in the world.
posted by cogneuro on Aug 28, 2008 - 26 comments

"People with synaesthesia can’t help but get two sensory perceptions for the price of one. Some perceive colours when they hear words or musical notes, or read numbers; rarer individuals can even get tastes from shapes." (previously) Neuroscientist Melissa Saenz of the California Institute of Technology has discovered a new form [pdf] of synaesthesia. Can you hear the dots? (QT)
posted by Kronos_to_Earth on Aug 5, 2008 - 75 comments

"Over and over he scoops up a chick with his left hand, expels its droppings with a squeeze of his thumb, opens its vent with his fingers, peers through the magnifying lenses attached to his spectacles and determines its sex." It's a dirty job (YT). Sexing chicks early is important so that the cockerels can be separated and culled^ or fed to be broilers^. The obvious differences take weeks to develop, so when the vent sexing method was developed in Japan in the 1920s, professional chicken sexers became sought after. [more inside]
posted by parudox on Nov 19, 2007 - 37 comments

We’ve detected background radiation from the Big Bang. We’ve sent explorers to the bottom of the ocean and the moon above us. We have images of the individual atoms of which our world is made. But we cannot have direct access to the sensory experiences of another human being. Language can help to bridge the gap but it is an imperfect tool. The closest we have come is Brain Fingerprinting and even that only indicates recognition of a scene or object; it does not capture the actual visual memory of the scene or object. This may soon change. Several years ago, researchers at Berkeley wired a cat’s neurons to a computer and were able to obtain videos of what the cat was seeing.
posted by jason's_planet on Aug 14, 2006 - 50 comments

Color Stereo Stereograms Directory
posted by Gyan on Feb 4, 2006 - 7 comments

How do we see? This site by Dr. Dale Purves makes it obvious we don't see things like a camera in any way. Check out the interactive demos, test your perceptual abilities, and read the research explaining why this happens. Number 12: Color Contrast Cube is particularly startling. Warning: Totally Flash interface, but appropriate for subject matter. More experiments at a less Flash-y associate's site.
posted by JZig on Feb 10, 2005 - 19 comments

The McCollough effect is a visual illusion somewhat similar to regular color aftereffects, but the working mechanism is different, and despite a wealth of theories, not entirely explained. Once the effect is established, it does not seem to go away and can last for days or even weeks. Proceed at your own risk.
posted by ikalliom on Apr 10, 2004 - 22 comments

A professor of vision science at MIT understands that life isn't just black and white, even though we often see it that way. This amazing illusion proves it, and these slick, fast-loading, Flash demonstrations of lightness perception show how it's done. (My favorite is the "Koffka Ring".) White paper here, for deeper background.
posted by taz on Sep 27, 2002 - 29 comments