A mindtrap is constructed of crystal and wire. It is only possible to activate it in Shayol Ghul, using the blood and saliva of the channeler, due to the malleability of reality there. Using a cour'souvra, the victim's soul, or at least the essence of it, is trapped. The victim can feel it trapped in the cour'souvra and know when someone is touching it. The holder of the person's cour'souvra has complete control over that person. Should the cour'souvra be crushed, that person will become a mindless puppet, subject to the will of the holder. Channeling in the presence of the cour'souvra you are trapped in, is very painful; the nearer, the more the pain.
We also don't know if the Moghedien's mindtrap is still in function after the new sealing of Shai'tan by Rand. If so she will live a very particular life as damane. Her cour'sovra probably is now sequestered by the sul'dam and she has to explain to them his function, to evade the risk they break it.