The brain probe is a machine used by the Cylons as a means of extracting information from humans who are uncooperative.
The machine works by tapping the nerve impulses to and from the brain, and then storing them to computer memory. Two Centurions are needed to run the machine, while a third Centurion remains to assist, in the event the subject requires restraint. The process is unpleasant to humans, but survivable with no apparent brain damage.
Vulpa orders the Centurions to attach Cadet Cree's cortex to the brain probe, after which Cree is rendered unconscious (TOS: "The Gun on Ice Planet Zero, Part I").
Notes
- The Colonials have a similar technology, introduced in "War of the Gods, Part I" as psycho-electron recall. In addition, the Marvel comic series has a device named the memory inducer, which allows for the retrieval of old memories.