Non-invasive neuroprosthetics

Nature reports that by simply recording the brain’s electrical signals from electrodes on the scalp, researchers have enabled trained participants to reliably control computer equipment, a feat normally associated with physical implants in the brain.

This is part of the growing science of neuroprosthetics, that aims to create technology that directly interfaces with the brain.

It is being particularly championed for people with paralysis, who do not have the use of their limbs, or people with damaged sensory organs, who might have their senses improved by technological replacements.

Previous trials of the technology have resulted in electronic implants to replace damaged retinas and a microchip implant that allows a paralysed man to control a computer.

These sorts of technologies typically require complex, experimental and invasive surgery, so being able to control technology via a skull cap and surface electrodes would be a more convenient option.

One of the disadvantages, well known to scientists who use forms of EEG recording to research the brain, is that the skull ‘smears’ the signal from the brain. Furthermore, muscle activity can introduce large amounts of electricial noise into the recording.

To get round this, mathematical analysis is used to filter out the unwanted interference, usually by averaging over several trials of the same task, allowing underlying brain activity to be inferred.

This is not an exact science, however, meaning the moment-to-moment ‘decoding’ of electrical activity needed for instant control of technology is more difficult to acheive.

Link to article ‘Computer users move themselves with the mind’.