I was flipping through some of the multitudinous books in my bookcase, when I came across one loaded with a whole pile of Mind tricks and optical illusions. Seeing as how my focus for this project has centred around cognition and distortion of spatial perception, I was able to take inspiration from these carefully crafted illusions to enliven the room with a greater confusion of form and volume - to really facilitate critical and creative thinking in the Doctor's mind as he meditates. Certainly this means that for any other "normal people" your sense of sight in the space is disturbed and perhaps made a little uncomfortable.
This one works with grain of opposing directions to produce a three dimensional, dynamic effect.
This kind of optical trick is really irritating, because you know that the lines are parallel, but there is so much fine detail of working again in alternating opposite directions, that the eye cannot focus on the whole at once.
I like the radiating or pulsing effect that this one gives due to the difference in spacing of the lines.
This is one of the classic examples where the offset of the checker squares is enough to irritate the hell out of you.
This one I find particularly intriguing, as to how the two layers of (1) built columns, and (2) their surface treatment work together to distort the perception of equilibrium.