Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Electric' fish shed light on ways the brain directs movement

01.02.2007
Research could lead to improvements in prosthetic limbs and robots

Scientists have long struggled to figure out how the brain guides the complex movement of our limbs, from the graceful leaps of ballerinas to the simple everyday act of picking up a cup of coffee. Using tools from robotics and neuroscience, two Johns Hopkins University researchers have found some tantalizing clues in an unlikely mode of motion: the undulations of tropical fish.

Their findings, published in the January 31 issue of the Journal of Neuroscience, shed new light on the communication that takes place between the brain and body. The fish research may contribute to important medical advances in humans, including better prosthetic limbs and improved rehabilitative techniques for people suffering from strokes, cerebral palsy and other debilitating conditions.

"All animals, including humans, must continually make adjustments as they walk, run, fly or swim through the environment. These adjustments are based on feedback from thousands of sense organs all over the body, providing vision, touch, hearing and so on. Understanding how the brain processes this overwhelming amount of information is crucial if we want to help people overcome pathologies," said Noah Cowan, an assistant professor of mechanical engineering in Johns Hopkins' Whiting School of Engineering. In studying the fish and preparing the Neuroscience paper, Cowan teamed up with Eric Fortune, assistant professor of psychological and brain sciences in the Krieger School of Arts and Sciences, also at Johns Hopkins.

... more about:
»Cowan »Engineering »Fortune »Tube »nervous system

Cowan and Fortune focused on the movements of a small, nocturnal South American fish called the "glass knifefish" because of its almost transparent, blade-shaped body. This type of fish does something remarkable: it emits weak electrical signals which it uses to "see" in the dark. According to Fortune, several characteristics, including this electric sense, make this fish a superb subject for the study of how the brain uses sensory information to control locomotion.

"These fish are ideal both because we can easily monitor the sensing signals that their brains use and because the task we asked the fish to do -- swim forward and backward inside a small tube -- is very simple and straightforward," said Fortune, who also uses the fish to study the neural basis and evolution of behavior.

The fish prefer to "hide" inside these tubes, which are immersed in larger water tanks. In their research, Cowan and Fortune challenged the fish's ability to remain hidden by shifting the tubes forward and backward at varying frequencies. This required the fish to swim back and forth more and more rapidly in order to remain inside the tubes. But as the frequency became higher, the fish gradually failed to keep up with the movement of the tubes.

The team's detailed engineering analysis of the fish's adjustments under these conditions suggested that the animal's sensors and brains are "tuned" to consider Newton's laws of motion, Cowan said. In other words, the team found that the fish's nervous systems measured velocity, so the fish could accelerate or "brake" at just the right rate to remain within the moving tube.

"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," Fortune said. "Your brain has to do this all the time when controlling movement because your body and limbs, like a car, have mass. This is true for large motions that require planning, such as driving a car, but also for unconscious control of all movements, such as reaching for a cup of coffee. Without this sort of predictive control, your hand would knock the cup off the table every time."

The researchers' understanding of the complex relationship between the glass knifefish's movements and the cascade of information coming into their brains and bodies via their senses could eventually spark developments in areas as far reaching as medicine and robotics.

"That animals unconsciously know that they have mass seems obvious enough, but it took a complex analysis of a very specialized fish to demonstrate this," Fortune said. "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, which is critical for medical applications."

The team's use of both neuroscience and engineering principles and tools also make it an important project for other reasons.

"So far, we have used a series of engineering analyses to tease apart some important information about how the nervous system works," Cowan said. "As we move forward, we expect to discover other exciting aspects of brain function that suggest new ways to design sensory control systems for autonomous robots."

Lisa De Nike | EurekAlert!
Further information:
http://limbs.me.jhu.edu/
http://www.psy.jhu.edu/~fortune/

Further reports about: Cowan Engineering Fortune Tube nervous system

More articles from Life Sciences:

nachricht Researchers target protein that protects bacteria's DNA 'recipes'
21.08.2018 | University of Rochester

nachricht Protein interaction helps Yersinia cause disease
21.08.2018 | Schwedischer Forschungsrat - The Swedish Research Council

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>