The Talos Device was a type of technology created by the Vulcans in Second History.
This machine was developed for use by the Interstellar Alliance of Planets and was capable of mindprobing an individual on an extensive basis. The capabilities of the device meant it was used for treating criminals or for interrogation. However, it left a great deal of mental damage to the individual. When Spock made use of the device, he was horrified to learn its effects and later attempted to convince the Vulcan High Council to ban the use of the technology. However, it was used on Ensign James T. Kirk after he had killed his Vulcan academy instructor and was noted as being the last time it was used before the Vulcan High Council stopped using the device.
The Talos device left Ensign Kirk agitated with him suffering from mood swings as well as periods where he felt angry which were all believed to be attributed to the mental probes of the machine. (TOS novel: Killing Time)