Apple co-founder Steve Wozniak and father of the Mac Jef Ruskin may be pleased to hear that US scientists have created a robotic arm that can be controlled by thought.

Wozniak and Ruskin are advocates of the idea of a truly human interface through which we could communicate with computers. The scientific advance may mean that technology is a step closer to being able to create their ideal user interface.

Probes are inserted into the brain and interpret signals from individual nerve cells in the motor cortex. Since even the smallest of movements involve thousands of nerve signals too numerous to track, the scientists used a gadget to work out the most important signals, writes the BBC.

The computer algorithm averages out the dominant signals to obtain the overall movement picture, and the arm moves accordingly.

Currently the brains in question are those of unfortunate monkeys, but human tests are likely to begin within four years, say the scientists.