The mind was the consciousness of a sentient being. The term was sometimes used interchangeably with brain.
The Teller could detect guilt in people's minds. (TV: Time Heist)
After the Twelfth Doctor's mind was connected to a mind scythe, he showed Kygon Brox some "holiday snaps" from his memories. (COMIC: The Instruments of War)
Torchwood Three had a mind probe. They used it to scan Beth Halloran's mind, trying to discover whether she had attacked the burglars who broke into her house. (TV: Sleeper)
The TARDIS, as a metaphysical engine, was capable of entering the dimension of a person's mind, their imagination. (PROSE: Every Day)