This looks like a pile of wooden cubes with odd images on them.

Assemble them correctly, and you get a 3-D image of the brain…except
you can’t see it when you are done…

…because the image is entirely inside.
The real puzzle is this: Where do you get one? I found it on
three sites (
href="http://www.odditycentral.com/pics/the-brain-cube.html">1
2
href="http://damncoolpics.blogspot.com/2008/11/cube-brain-teaser-puzzle.html">3),
but nobody links to the original source.