First we hacked into the neuroSky chip and got serial information out of it concerning Alpha and Beta waves.

Then we process that by an Arduino to map it to the rotation of a servo motor rotating the polarized disk.

We transferred the sensors to ear clips for better fastening.

And mounted the rest of the hardware on a welding helmet frame.

There are a ton of documentation pics in this Flickr set.

polarized lensespolarized lenses   inline led resistorsinline led resistors   neurosky resetneurosky reset   mental block cuircuitmental block cuircuit   helmet with battery packhelmet with battery pack   finished helmetsfinished helmets