Thank you for correcting an ignorant post.  ++karma
If you dont know what your talking about, why post it and confuse other people and give mis-information?? Especially when dealing with a subject like helmets?
There is no protection in the world that you could wear that stops concussions. The reason being is, a concussion occurs because your brain matter gets "smushed" against your brain wall....Its a simple matter of momentum. If your head abruptly stops moving, your brain is still moving (has momentum) and presses up against your brain wall, causing the concussion...again...nothing in the world to stop that from happening.
A helmet, keeps your skull together and your brain matter inside, so you arent oozing brains on the slopes after you hit your head.
Think football and hockey helmets..probably the best designed helmets for impact sports yet the sports with the highest frequency of concussions....