Many scientists and researchers in the area of human prosthetics have been trying to develop artificial limbs that can mimic the functions of its organic counterpart. For the past couple years, however, these same people are looking into how we can have prosthetics that can interact with the brain directly.
Researchers from the University of Chicago, among other institutions, are taking us one step closer to realizing some people’s dreams of having an artificial limb that have the ability mimic the sensory functions of a real limb.
In their study, Sliman Bensmaia and colleagues, attempted to map out the sensory signals that have the potential to make prosthetics more sophisticated than ever before.
Through several experiments involving our close relatives, the monkeys, the researchers found that they were able to induce several ‘sensation’ or ‘feeling’ of touching a physical object via just electrical simulation alone.
For instance, Bensmaia and his partners trained a monkey to react a certain way after it touched a physical object. Using electrodes attached to the monkey’s head, the researchers were able to observe with great details which area of the brain was active at that moment. The researchers then combined their neural data from the monkey and some complex calculations to figure out how much electricity it would take to stimulate the monkey’s senses without having it actually touch anything.
The findings, although intuitive, are that it is possible to induce the sense of contact (where the skin has been touched), pressure, and contact events through the use of direct electrical manipulation of the brain. That is, they found that the monkeys’ reaction via electrical manipulation is similar to it having actually touched a physical object.
Despite these advancements, there are still a lot to be done as researchers continue to study—layer by layer—one of the most complex human organs.
“The algorithms to decipher motor signals have become quite a long way, where you can now control arms with seven degrees of freedom. It’s every sophisticated. But I think there’s a strong argument to be made that they will not be clinically viable until the sensory feedback in incorporated,” said Bensmaia. “When it is, the functionality of these limbs will increase substantially.”