New research could soon help patients suffering from years of paralysis once again feel the shape of an object. This accomplishment is a massive leap forward for electrical brain stimulation and has helped two patients temporarily regain their sense of touch.
Previous attempts to restore touch through brain stimulation have been limited to simple contact sensations—essentially, the difference between touching and not touching something. But our hands experience far more: textures, edges, motion, and even curvature.
Researchers from the Chalmers University of Technology in Sweden set out to revive these richer sensations in paralyzed patients. Working with two participants who had partial paralysis from spinal cord injuries, the researchers used MRIs to identify brain regions linked to movement and sensations so they could help the patients regain their sense of touch.
The participants imagined moving their fingers and feeling objects, helping the researchers pinpoint specific brain areas. Dozens of tiny electrodes were then implanted into these regions to deliver targeted electrical stimulation.
With the implants in place, the participants regained their sense of touch temporarily and could feel as though they were holding familiar objects, such as a can or pen. The stimulation even mimicked the sensation of motion across their fingers.
The researchers tested the implants further by connecting electrodes to a robotic arm controlling a virtual car steering wheel. When the wheel moved suddenly, the electrodes transmitted signals to his brain, making it feel as though the robotic arm were his own.
The researchers reported that by counteracting the wheel’s movements, the patient was able to keep the car on track 80 percent of the time. These results offer hope for greater independence for many patients with paralysis.
Robotic arms controlled via brain stimulation could allow people with paralysis to perform tasks like cooking or shopping. However, challenges remain, including high costs and the need for skilled neurosurgeons to implant the electrodes needed to help patients regain their sense of touch.
Still, researchers believe this technology could become a reality within a few years, bringing a new level of autonomy to people with spinal cord injuries.
