Neural dampener
A Majalan neural dampener
A neural dampener or neural dampening device was a device worn on the head, designed to reduce electrical activity in the brain.
In 2259, the Majalan Elder Gamal conspired with the Prospect VII colony to use a neural dampener on his son, so that he would be unable to fulfill his duties as First Servant. (SNW: "Lift Us Where Suffering Cannot Reach")