You're spot on about the subliminals there. The background was dripping with concentrics, and there were also circles in the metalwork on the balcony he was standing on. Very cleverly done, as you'd expect.

The thing that's really oiques my interest is the way that it was apparently possible to use the motif in such an experiment. Obviously it's not anything like proof of psychic communication, but whatever strange neuro-linguistic-programming type stuff he uses, Mr B chose this motif* possibly because he's ware of the depth to which it's encoded in the human visual cortex. I can't quite express it, but it really seems to speak to me about why the folk who carved cup and ring marks chose such an abstracted motif to replicate over and over and over, and why it' such an absorbing subject once your brain keys into it. It would appear that rock art can, in some instances, make your brain go a bit strange if you allow it to do so :)

*I'm assuming he had at least some influence in the thing the artist painted. The Stonehenge link may have been an attempt to hack into something iconographically mysterious enough to induce a sense of 'Oooo-wee-oo-wooo'. Cracking good stuff however it was done.