The mind probes were devices created by the Nakai for the purpose of retrieving knowledge from an another person's mind. The devices work in pairs, creating a one-way link between two subjects to transfer information from the transmitter to the receiver.
The devices are somewhat curved with three lights on the side, the color of which denotes the function. The transmitter, indicated by yellow, transmits the memories of the person it's attached to when prompted. The receiver, indicated by red, controls the link, allowing the wearer to read the mind of the one wearing the transmitter at will. The one transmitting can resist the probe.
The devices cause momentary pain when first attached. The transmitter also caused severe pain to Col. Everett Young when he used it while controlling the body of one of the aliens; however, this may have been due to a conflict with the long-range communication device, as the alien ceased convulsing once the communication link was broken. (SGU: "Space")
When Nicholas Rush was captured, one such device was used on him. He managed to resist giving away anything important. Through the use of the mindprobe the Nakai was able to understand English. When Young used the communication device to take over and alien aboard the mothership and free Rush, Rush instructed him in the use of the device. Young attached the transmitter, and was disabled by severe pain almost immediately. Rush used the probe to learn that Young was controlling the alien. As a side effect, the communication link was severed. Rush used the probe again to get a basic overview of the ship and its systems from the alien Young had inhabited. (SGU: "Space")
Behind the Scenes Edit
The mind probe seems to function similarly, and indeed emits a similar tone when attached to a subject, as the Tok'ra memory recall device.