Neuronal stimulation allows brain to ‘sense’ artificial limbs

Scientists have long been trying to find a way for people with prostheses to "feel" their limbs Keystone

Researchers at the University of Geneva have found a way for the brain to receive sensory information from an artificial limb using a novel brain-machine interface – a landmark discovery that could further the development of more sophisticated prostheses. 

Until now, brain-machine interfaces have allowed only a one-directional relationship between the brain and a prosthesis. Electrodes are used to decode neuronal activity – such as a desire to move an artificial limb – and translate it into movement. But it has previously not been possible for the brain to receive signals of perception or sensation from the artificial limb in return. 

But now, by using mice as research subjects, the Geneva-based research team has found that rodents can quickly learn to control an artificial limb through a system of neuronal stimulation and reward. By imaging and measuring neuronal activity, the researchers were able to artificially stimulate the mouse’s brain using flashes of light, rather than electrodes, so that it perceived and integrated these signals as feedback from prosthetic movements. 

So far, the researchers have been able to provide sensory feedback for a single movement of an artificial limb. They are continuing to explore whether feedback from multiple channels and movements is possible, allowing for more complete control of prostheses by the brain. 

This new relationship between the brain and a prosthetic limb could lead to the development of more sophisticated prostheses that can be moved more quickly by the brain, and that could potentially feel objects with sensitivity to pressure.