Wagon Wheel Illusions

An NYRB article: In the River of Consciousness, by Oliver Sacks, brought together a number of issues regards perception that I have always been intrigued with. Oliver Sacks is a Neurologist and science writer, known for his engaging book The Man Who Mistook his Wife for a Hat, fictionalized in the film Awakenings. [Correction: A reader reminds me that it was actually based on his nonfiction book also called Awakenings]

Sacks discusses the work of Dale Purves of Duke University on the Wagon-Wheel Illusion. Its probably the best-known, yet incompletely understood visual illusion. You see it in movies when a cart with spoked wheels moves quickly, the wheels appear to rotate slowly backwards. The cause of this illusion is the synchronization of film speed with motion, essentially a flaw in the brain mechanism that allows us to see continuous motion in film. You can see the illusion in environments other than film, though, and this provides some insight into our visual systems.

Purves goes on to suggest that this effect demonstrates how our perception of time is carved into packets of interaction with our neural systems. Marketing implications?

Duke's Perception Lab has done considerable work in understanding the effect, and how is links to our perception of the world, here is their detailed paper. Purves has a new book out: Why We See What We Do, that covers some of the same territory.

Comments

[Jack]

Wasn't it Sacks' book Awakenings that was portrayed in the fillum Awakenings? And I didn't think it had been fictionalized - just actor-ized.

[Franz]

You are right, it was Awakenings ... on your other point I read the IMDB posts, and although based on real events and people, it was fictionalized to create a complete story. Thanks.

[Pooya]

Hello, Nice weblog. Please take a look at the article below about Wagon Wheel Illusion.

P. Pakarian, and M.T. Yasamy. 2003 "Wagon wheel illusion under steady illumination: real or illusory?" Perception 32(11): 1307-1310.