Neuroscientists from the University of
Chicago (UChicago) have developed a computer model that can simulate the
response of nerves in the hand to any pattern of touch stimulation on
the skin. The tool reconstructs the response of more than 12,500 nerve
fibers with millisecond precision, taking into account the mechanics of
the skin as it presses against and moves across objects. In addition to
its impact on the basic understanding of how these sensations work, the
model is also a foundation for restoring touch in bionic prosthetic
hands for people with amputations.
Population responses for different tactile experiences.
Image courtesy of the Proceedings of the National Academy of Sciences.
To
achieve realistic feelings of touch, neural engineers try to reproduce
the natural patterns of nerve activity generated when we manipulate
objects. The computer model provides engineers with the nerve output
generated by a given stimulus, which can then be recreated in a
prosthesis by electrically stimulating the nerve through an interface
implanted in the body.
The
software will allow scientists to see how entire populations of nerve
fibers respond when we interact with objects. The model will allow
scientists to better understand how the nerve responds to touch, and can
be used to build realistic sensations into bionic hands for amputees.
“Almost
everything we know about how the nerve responds to stimulation on the
skin of the hand is built into this model,” said Sliman Bensmaia, PhD,
associate professor of organismal biology and anatomy at UChicago, and
principal investigator for the new research. “Finally, you can see how
all these nerve fibers work together to give rise to touch.”
Details of the model were published in the June issue of the Proceedings of the National Academy of Sciences. The study builds upon years of research by Bensmaia’s team about how the nervous system and brain perceive the sense of touch.
Bensmaia
and his team validated the output of the model against data from a wide
variety of experiments conducted by other research teams, and show that
it matches their output with millisecond precision. The software will
be available as a free download, so other engineers can begin using it
in their own work.
“Using a model to reproduce a biological system
precisely is challenging, and we have been working on this simulation
for a very long time. But the final product, I think, is worth it,”
Bensmaia said. “It’s a tool that will yield insights that were
previously unattainable.”
Editor’s note: This story was adapted from materials provided by the University of Chicago Medical Center.
