Neuroscientists from Duke University’s Center for Neuroengineering have successfully endowed monkeys with the ability to move robotic wheelchairs using thought alone.
The dazzling advancement is the subject of a new study published today in Scientific Reports.
“In some severely disabled people, even blinking is not possible,” said Dr. Miguel Nicolelis, study author and co-director of the Duke Center for Engineering, in a statement. “For them, using a wheelchair or device controlled by noninvasive measures like an EEG (a device that monitors brain waves through electrodes on the scalp) may not be sufficient. We show clearly that if you have intracranial implants, you get better control of a wheelchair than with noninvasive devices.”
The brain-machine interface works by utilizing signals from neurons in two regions of the monkey’s brain, regions specifically involved with sensation and movement.
Scientists started experimenting with the technique back in 2012. The researchers implanted an array of microfilaments in the premotor and somatosensory regions of two rhesus monkeys. They then trained the monkeys to navigate the wheelchair towards a goal: a bowl of grapes. All the while, the scientists monitored the monkeys’ brain activity. A computer system then translated the brain signals into digital motor commands capable of controlling the wheelchair’s movements.
As the monkeys’ proficiency at controlling the wheelchair improved, the scientists saw brain signals that showed the monkeys were thinking about the distance between them and the grapes.
“This was not a signal that was present in the beginning of the training, but something that emerged as an effect of the monkeys becoming proficient in this task,” said Nicolelis. “This was a surprise. It demonstrated the brain’s enormous flexibility to assimilate a device, in this case a wheelchair, and that device’s spatial relationships to the surrounding world.”
The researchers note in their study that brain-machine interface will likely have a profound clinical impact, and improve mobility for the disabled.
According to Popular Science, the surgery to install the device is minimally invasive and some implants have been left in a monkey’s brain for seven years. What’s more, Nicolelis believes they could be left in the brain for much longer.
The experiments measured the activity of nearly 300 neurons in each monkey, but Nicolelis’ lab has reported the ability to record up to 2,000 neurons in the past. Before seeking to start trials using humans, the team wants to record more neuronal signals in monkeys to improve the technique’s accuracy.