A schizoid accelerator was used in the first major phase of a particular Dalek operation on the human brain. It destroyed the human ego. Afterward, during the second phase of the operation, the surgeon would implant a Skaro mesmeristor 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. (COMIC: City of the Daleks)