Neural suppressor

A neural suppressor was a device capable of suppressing the teleptahic abilities of a telepathic being.

In the mirror universe, $𝜇$ had neural suppressors implanted in both of her daughters in order to make it easier to control them. When $𝜇$ infiltrated Lwaxana's establishment, the Sacred Chalice, he had a neural suppressor that was able to keep people from reading his mind rather than suppressing any abilities he had. (SS TNG (The Sacred Chalice))