Scientists have struggled to understand exactly how the brain guides complex movements of human limbs from holding the newspaper steady to picking up a cup of coffee.
Johns Hopkins University robotics and neuroscience researchers found some tantalizing clues in an unlikely mode of motion: The undulations of a tiny tropical fish.
Their findings shed light on the communication between the brain and body and also has far-reaching implications in the development of better prosthetic limbs and improved rehabilitation.
“All animals, including humans, must continually make adjustments as they walk, run, fly or swim through the environment,” Johns Hopkins? Whiting School of Engineering assistant professor Noah Cowan said.
Studying a small, nocturnal South American fish called the glass knifefish, which navigates by producing small electrical signals, they found that the animal?s sensors and brains are “tuned” to consider Newton?s laws of motion. In particular, their systems measured velocity, so the fish could accelerate or “brake” in time to remain hidden within a moving glass tube, Cowan said.
“The fish were able to accelerate, brake and reverse direction based on a cascade of adjustments made through their sensory and nervous systems, in the same way that a driver approaching a red light knows he has to apply the brakes ahead of time to avoid overshooting and ending up in the middle of a busy intersection,” Krieger School of Arts and Sciences assistant professor Eric Fortune said in a statement. “With this basic knowledge, we hope one day to be able to tune artificial systems, such as prosthetics, so that they don?t have the jerky and rough movements that most robots have.”
The researchers? findings were published in the Wednesday issue of the Journal of Neuroscience.
