The realm of science-fiction has just taken a big stride towards the world of science fact, with the creation of a prosthetic arm that can be moved solely by thought. Two monkeys, using only electrodes implanted in their brains, were able to feed themselves with the robotic arm complete with working joints.

Bionic limbs have been fitted to people before but they have always worked by connecting to the nerve endings in the chest. This is the first time that a prosthetic has been placed under direct control of the relevant part of the brain.

The study, carried out by Meel Velliste from the University of Pittsburgh, is a massive leap forward in technology that lets the brain interface