An old example of AVS technology..
I thought others might be interested in this intriguing example of early AVS technology ( albeit used in a more entertaining rather than entraining way). The light source is clearly some kind of high voltage strobe device. Certainly makes you appreciate the compactness of modern AVS gear :)
The whole film on YouTube is in three parts
Go straight to 4min 55sec into the linked clip to see the AVS machine .
The film is called The Sacred Mushroom made in 1961 and was about a group of researchers investigating the reported ESP enduced by mushrooms in a remote community headed by Mexican "brujos" (witches).
http://www.youtube.com/watch?v=t3NMqCij7cI