Here’s a roundup of some of the news you probably missed. Ever wanted to know what your pet is really thinking? Find out how. Plus, why a good night’s sleep could give your brain a spring clean, and what the prosthetic limbs of tomorrow will feel like.
Prosthetic limbs have become amazingly sophisticated in recent years. Robotic arms can move in any dimension a real arm can, complete with individually moving,
jointed fingers. They can even be controlled by the power of thought alone! (No, they’re not toys, even though they sound like great Christmas gifts for gadget fans.) We’ve nearly created Robocop technology, but something crucial is still missing: a sense of touch. Our ability to feel lets us know when we make contact with things, where they are touching us, how much pressure we are applying, and so on. We can’t get the same information from just watching what we’re doing – just try unlocking your front door with fingers numbed from the cold! Without this sense of touch to give us feedback, interacting with the world through a robotic arm remains clumsy, and we will inevitably drop (or crush) things occasionally. Not too much of a problem if it’s a coffee mug, but picking up the family pet is probably risky. But all that may be about to change: scientists at the University of Chicago, Illinois, led by Sliman Bensmaia, have managed to artificially create a
sense of touch by delivering signals directly to the brain. They have tested their new technique with Rhesus macaque monkeys – but, in theory, the same process could be used for human amputees.
Feeling like a monkey
In the first part of the experiment, the researchers trained a group of monkeys to look left or right depending on which of their fingers was touched, or how hard they were prodded. They then implanted tiny electrode wires into a part of the brain that deals with touch sensation (known as the somatosensory cortex) and measured brain activity there. By touching a monkey’s skin at the same time as monitoring its brain activity, the team could precisely identify the areas that ‘felt’ being touched in different places. They then used these same electrodes to deliver electrical stimulation in these same places (corresponding to different fingers), and adjusted the strength of the signals to simulate different pressures. And, sure enough, the monkeys responded in nearly the same way as if they had been physically touched: the monkeys
looked in the correct direction whether they had been physically touched or electronically stimulated.
The scientists claim that their results provide a blueprint for converting the output from touch sensors on a prosthetic arm into a real sensation of touch via a direct connection with the brain. If successful, this new technology would help someone wearing a prosthetic arm to handle things more precisely – and it would also make the prosthetic ‘feel’ more a part of them. It’s still early days, but this is a vital step towards making truly useful brain-controlled prosthetic limbs, and Bensmaia thinks these results will bring such devices closer to being tested in humans. In the meantime, other scientists are developing pressure sensors advanced enough to be used with this technology. So it may not be long before people who have lost limbs, or sensation in their limbs, could again be reaching out to feel the touch of someone they love.
BELOW: New research at the University
of Chicago is laying the groundwork for touch-sensitive prosthetic limbs
that one day could convey real-time sensory information to amputees via a direct interface with the brain.