Monkey's Thoughts Make Robot Walk from Across the Globe
DURHAM, N.C. – In a first-of-its-kind experiment, the brain
activity of a monkey has been used to control the real-time
walking patterns of a robot halfway around the world, according
to researchers at Duke University Medical Center.
The Duke team is working with the Computational Brain
Project of the Japan Science and Technology Agency (JST) on
technology they hope will one day help those with paralysis
regain the ability to walk.
"We believe this research could have significant
implications for severely paralyzed patients," said senior
study investigator Miguel Nicolelis, M.D., Ph.D., the Anne W.
Deane Professor of Neuroscience at Duke. "This is a
breakthrough in our understanding of how the brain controls the
movement of our legs, which is vital information needed to
ultimately develop robotic prosthesis."
Researchers used some of the most sophisticated methods
available to capture activity from hundreds of brain cells
located in multiple areas of the brain. To collect this
information, two rhesus monkeys were implanted with electrodes
that gathered feedback from cells in the brain's motor and
sensory cortex. This technology recorded how the cells
responded as the monkey walked on a treadmill at a variety of
speeds and while walking forward and backward. At the same
time, sensors on the monkey's legs tracked the actual walking
patterns of the legs while moving.
Using mathematical models, the researchers were able to
analyze the relationship between the leg movement and brain
cell activity to determine how well the information gathered
from the brain cells was able to predict the exact speed of
movement and stride length of the legs.
"We found that certain neurons in multiple areas of the
brain fire at different phases and at varying frequency,
depending on their role in controlling the complex,
multi-muscle process of motion. Each neuron provides us with a
small piece of the puzzle that we compile to predict the
walking pattern of the monkeys with high accuracy," Nicolelis
"In this experiment, we were able to record brain activity,
predict what the pattern of locomotion will be and send the
signal from the motor commands of the animal to the robot,"
Nicolelis said. "We also created a real-time transmission of
information that allowed the brain activity of the monkey in
North Carolina to control the commands of a robot in Japan. As
a result, they can walk in complete synchronization."
"We are delighted with the remarkable outcome of this
collaboration between Duke University and JST, as now we can
further advance our research to better understand how the brain
processes information," said Mitsuo Kawato, M.E., Ph.D.,
director of ATR Computational Neuroscience Laboratories and
research director of the Computational Brain Project of
The experiment built on earlier work conducted by Nicolelis'
laboratory in which monkeys were able to control the reaching
and grasping movements of a robotic arm with only their brain
"We are also exploring how the brain processes feedback
sensations – both visual and electrical – from the robot. This
feedback plays a critical role in completing the act of
walking. In essence, we are seeking to capture the information
that the foot sends to your brain when it touches the ground as
you walk," Nicolelis said.
He added, "The most stunning finding is that when we stopped
the treadmill and the monkey ceased to move its legs, it was
able to sustain the locomotion of the robot for a few minutes –
just by thinking – using only the visual feedback of the robot
The researchers are estimating that work will begin within
the next year to develop prototypes of the robotic leg braces
for potential use with humans.
This research was supported by the Anne W. Deane Endowed