Escher Circuits: Hacking visual perception

Uh oh... http://en.wikipedia.org/wiki/Snow_Crash

The Escher circuits make me think of the 'Mentats' (humans trained to process vast quantities of information like computers) in Frank Herbert's Dune series.

And before that, Dave Langford's 1988 BLIT: http://en.wikipedia.org/wiki/BLIT_%28short_story%29 (includes link to text, only a few pages, and follow-ups).

Besides the original Medusa/basilisk/cockatrice legends.

I wonder if I've been "damaged" by staring at too many both-woman-and-frog-style pictures and Escher drawings in my childhood. My brain just keeps flipping perspective at random as I traverse down the circuits.

My subconscious doesn’t get the NOT gates. AND and OR gates work fine, though. Really cool work.

It took me a while to "get" the not gates (the prism ones on the right of figure 4).

If that's what you're stuck on, note that the bottom half of the right two diagrams can be seen "from underneath looking into the open trapezoid" (left of the two rightmost) or "from above looking at outsides of (truncated-pyramid-like) trapezoid" (right of two rightmost). Keep staring...