The robotic hand mimics the movements of a person's real hand, based on real-time functional magnetic resonance imaging (fMRI) of their brain activity. It marks another landmark in the advance towards prosthetics and computers that can be operating by thought alone. An fMRI machine probes activity within the brain by monitoring blood flow to different regions. It uses a powerful magnetic field combined with radiofrequency pulses to probe the magnetic state of hydrogen atoms in water molecules within body tissue.
An alternative and more portable method is to measure electrical activity inside the brain using electrodes either implanted in brain tissue or attached to the scalp. US researchers have previously used brain implants to allow monkeys to remotely operate robotic arms.
One day, Kamitani believes, the robot hand could be made to respond faster than a user's real one. "The next step for me is to decode faster, even before the person moves their hand, by reading the brain activity related to intention," he told New Scientist.
But he admits that fMRI scanning technology must be improved dramatically before this could be possible, and before the system could be used practically. "We will need several breakthroughs in related technologies, including those for brain scanning hardware, before this type of non-invasive systems will be used in daily life," he says.
For now, the fMRI technique is too cumbersome and expensive but could help scientists better understand how the brain works because it provides higher resolution.