Skaro mesmeristor

 was the object of the second major phase of a particular Dalek operation on the human brain. Following the use of the schizoid accelerator — which destroyed the human ego — the mesmeristor was implanted in the brain to convert the human "into a humanoid" which would obey the Daleks without question. Jeff Stone witnessed a lecture on the proper surgical procedure regarding this device whilst on Skaro. (DWA: City of the Daleks)
 * ''It's possible the author meant to call this device a "mesmerisor" or a "mesmeresistor", but the spelling used by the letterer was definitely "mesmeristor".