Writing the Brain & Body column for MSN has put me in touch with some wildly intelligent people. Some column installments explore the bleeding-edge work of neuroscientists while other pieces collect the gee-whiz facts that come up along the way. 7 Weird But True Facts About the Brain is among the latter.

Research for this article turned up brain benders like the Checker Shadow Illusion shown here. The boxes marked A and B are the exact same shade of gray. No fooling.

Here are some additional lightness illusions that will mess with your head.