Best known for having created a full body robotic suit which helped a paralysed man to kick off the 2014 FIFA World Cup in Brazil, the neuroscientist Miguel Nicolelis does not stop to impress.
Coming from Duke University, he recently carried out a research on two rhesus macaques which involved the monkeys having electrodes implanted deep in their brains consequently allowing them to steer a wheelchair using thought alone.
This research has risen hope for paralysed people: advances in biomechanical engineering, cognitive neuroscience, mathematics and computer science have come together to offer optimism to legions of people who suffer from spinal cord injuries.
Miguel Nicolelis’ team initially recorded activity in the motor and sensory cortices of monkeys riding around in chairs. A computer decoder correlated this neural activity with the direction of movement of the chair and after the training period was over, the brain-machine interface worked in reverse – using the neural inputs to actually steer the chair. “They can reliably steer the wheelchair to get a grape,” Nicolelis said in a National Geographic report. “They like grapes.”
Across the decades, scientists have had the ability to record brain waves (EEG) or even implant specialised arrays of electrodes into the cerebral cortex, the outer layer of the brain. The goal of the research is partly to help develop a “brain pacemaker” implant that would pick up clearer signals from thoughts to help future robotic prosthetics.
Each year 130,000 people suffer spinal cord injuries worldwide, and for more than a decade, researchers have sought to help these patients using robotic interfaces with the brain. The findings of the research were presented to the Society for Neuroscience (SfN) conference in Washington, DC.
Paraplegics are given the opportunity to walk again by using an exoskeleton that is controlled by brain signals that are associated with movement. Describing a pilot research in which eight paralysed patients walked using a robotic exoskeleton that moved in response to readings of the patients’ brain waves, Nicolelis states that some of his patients “feel they are walking on sand” and that their brains are fooled to think it is themselves walking forward rather than the machine. Similarly, in fact, analysis of the monkey’s brain signals showed that the animal learned to assimilate the robot arm into her brain as if it were her own arm.
Eberhard Fetz, a neuroscientist of the University of Washington and colleagues have similarly showed that brain interfaces in monkeys can “bridge” the damaged area in a spinal cord injury, allowing voluntary movements of muscles.
An interesting finding about the patients and their experience with walking with an exoskeleton is such that “if they walk slow, they feel that they are walking on sand; faster, that they are on grass, and fastest that they are walking on hot pavement,” creating a “phantom” feeling.
Although these new technologies offer a window into how the brain creates movement, there is a substantial amount of work which still needs to occur before it can be consolidated. Daofen Chen, a neuroscientist of the National Institute of Neurological Disorders and Stroke says, “We are far from understanding the brain well enough to expect them to serve as solutions.”
Fetz, however, suggests that enough progress is being made to feel good about developing robotics that might help patients. “One of the benefits of this whole area of research is that training patients on these devices helps them become part of the research team,” Fetz says. “We are working together.”
Astrid Nardecchia
