Researchers at the University of Pittsburgh have shown that providing direct sensory feedback to the brain dramatically improves control of a robotic arm by an affected patient. The arm was operated through a brain-computer interface, but the system also included brain implants in an area of the brain responsible for sensory feedback. When the patient completed the tasks with the arm, it was much faster when sensory feedback was activated, mimicking the way someone can feel an object being grabbed with the hand. The technique could make brain-computer interface systems easier and more intuitive to use and therefore practical.
Brain-computer interfaces are ready to transform the lives of amputees and people without complete motor or sensory control of their limbs. From wheelchairs to robotic prostheses, the opportunities are huge. However, using a limb is difficult if the objects with which it interacts cannot be felt. Imagine trying to perform a simple task if your arm is completely numb.
To address this, this latest brain-computer interface includes sensory feedback in the form of brain implants in the somatosensory cortex, allowing the user to receive sensory tactile feedback while operating a robotic arm. The system also includes implants in the motor cortex, which allow the user to control the arm.
The first and only user of the system, Nathan Copeland, is the first patient in the world to receive these sensory implants. After a car accident, Copeland has limited the use of his arms and volunteered to have the implants inserted as part of a clinical trial.
In this recent study, Copeland used the robotic arm to complete several tasks and the researchers compared the time it took with and without sensory feedback. The results show that Copeland completed the tasks almost half the time when sensory feedback was activated (approximately 10 seconds per task, compared to 20 seconds without sensory feedback).
Here is a quick example of Mr. Copeland doing the same task with and without the new stimulation:
“In a sense, this is what we expected to happen, but perhaps not to the degree we observed,” Jennifer Collinger, a researcher involved in the study, said in a press release. “Sensory feedback from the limbs and hands is very important for doing normal things in our daily lives, and when that feedback is lacking, people’s performance is impaired.”
The results suggest that the development of more advanced sensory feedback systems could significantly improve the user performance of the brain-computer interface. “When even the limited and imperfect feeling is restored, the person’s performance improved in a fairly significant way,” said Robert Gaunt, another researcher involved in the study. “We still have a long way to go to make the sensations more realistic and bring this technology to people’s homes, but the closer we can recreate normal contributions to the brain, the better off we will be.”