Brain chip

There were two types of brain chip pico surgery performed by humans in the year 200,000. The first, known as the head chip, was a small processing chip implanted at the base of the skull which cost one hundred credits at Satellite Five.

The more expensive model, the infospike, was a receptor chip implanted in the forehead. This surgery cost ten thousand credits. When activated, the forehead opened up, exposing both the chip and the naked living brain of the implantee.

Once the receptor chip was activated, compressed news information was streamed into the person's brain. They became, in effect, part of the hardware. Their brain was the computer. However, the brain only processed the information; it did not retain it after the download. In effect, the brain acted as the passive receptacle of information, without memory of the information transmitted.

The implantee had the choice of how to trigger activation. Adam Mitchell had the snapping of his fingers (or those of any person nearby) set as the default for him. (TV: The Long Game)

Dorium Maldovar had a media chip implanted in his head that he used to keep himself entertained after he was beheaded by the Headless Monks. (TV: The Wedding of River Song)