Thought maker

A Thought Maker is a device that is used to alter the brainwaves of a person. It can either be used by a person on themselves, or it can be used by one person to manipulate another person.

In 2364, the Ferengi DaiMon Bok used a thought maker on Captain Jean-Luc Picard as part of his plans to take revenge on Captain Picard for the death of his son. Bok manipulated Picard into boarding the USS Stargazer, in which Picard defeated Bok's son nine years earlier in order to have Picard attack his own ship, the USS Enterprise (NCC-1701-D). Fortunately, Lt. Commander Data was able to prevent Picard from attacking the Enterprise, and Riker was able to get through to Picard long enough to have the Captain destroy the thought maker. When the Ferengi found out what Bok was doing, Bok was relived of his command. (TNG episode The Battle).

Six years later, Bok - who had bought his freedom some time ago returned with a second plan to take revenge on the Enterprise. When Bok appeared to the Captain in private, Picard was concerned that Bok was again using thought makers. But a scan by LaForge revealed that thought makers were not being used. Instead, Bok was using a subspace transporter to actually board the Enterprise. (TNG episode Bloodlines)