Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Optic Flow: A Step in The Right Direction

19.11.2007
The way objects appear to stream by us as we move through the world is a phenomenon called optic flow. Think of the street signs and storefronts that sail across the car windshield as we drive. That’s optic flow in action. Brown University cognitive scientists have now shown, in research to be featured on the cover of Current Biology, that optic flow plays a critical role in continuously recalibrating our steps as we walk.

The motion we perceive with our eyes plays a critical role in guiding our feet as we move through the world, Brown University research shows.

The work was conducted in Brown’s Virtual Environment Navigation Lab, or VENLab, one of the largest virtual reality labs in the country. It appears online in Current Biology and will be featured on the journal’s Dec. 4, 2007, cover. The findings shed important new light on the phenomenon of optic flow, the perceived motion of visual objects that helps in judging distance and avoiding obstacles while walking, driving and even landing a plane.

Perception in action, or the intersection of how we see and how we move, is the focus of research in the laboratory of William Warren, chairman of Brown’s Department of Cognitive and Linguistic Sciences. In the VENLab, Warren and his team have studied optic flow by having human subjects wear virtual reality goggles and navigate through virtual obstacles in the darkened room.

... more about:
»Brain »Optic »Visual »walk

In 2001, the Warren lab showed for the first time that people use optic flow to help them steer toward a target as they walk. But what happens when you are standing still? If you are not walking and not getting the constant stream of visual information that optic flow provides, how do you begin moving toward a target? How do you know which way to direct your first step?

To get an answer to this question, the team created a virtual display that simulates a prism, bending light so that the visual scene shifts to one side. The target – in this case, a virtual doorway toward which subjects were told to walk – appeared to be farther to the right than it actually was. A total of 40 subjects ran through about 40 trials each, with everyone trying to walk through the virtual doorway while wearing the simulated prism. Half those subjects had optic flow, or a steady stream of visual information, available to them. The other half did not.

The researchers found that, on average, all 40 subjects missed the doorway by about five feet on the first few steps. But after a while, subjects adapted and were able to walk straight toward the doorway. Then the simulated prism was removed, and subjects were again asked to walk to the virtual doorway. Surprisingly, they all missed their mark on the opposite side because their brains and bodies had adapted to the prism. After a few tries, subjects quickly readjusted again and were able to walk straight to the doorway.

Hugo Bruggeman, a postdoctoral research fellow in the Warren lab who led the research, said the kicker came when they compared data from subjects who had optic flow available during the trials with data from those who did not. When subjects had optic flow, they took a straight path toward the doorway and made it, on average, in just three tries. When optic flow was eliminated, and subjects had only a lone target to aim for, it took an average of 20 tries before they walked straight to the target.

“With optic flow, it is easier to walk in the right direction,” Bruggeman said. “Subjects adapted seven times faster. This suggests that with a continuous flow of visual information, your brain allows you to rapidly and accurately adapt your direction of walking. So we’re constantly recalibrating our movements and our actions based on information such as optic flow.”

This finding could have practical applications, particularly in robotics, where it can be used to produce machines with more accurate guidance capabilities. But Warren said the real value of the work rests with the deeper scientific principle it points up.

“We tend to think that the structures of the brain dictate how we perceive and act in the world,” Warren said. “But this work shows that the world also influences the structures of the brain. It’s a loop. The organization in the brain must reflect the organization and information in the world. And this is a universal principle. All animals that move use optic flow to navigate. So whether you’re a fly landing on a leaf or a pilot landing on a runway, you may be using the same source of sensory information to carry out your task.”

Wendy Zosh, a graduate student in the Department of Cognitive and Linguistic Sciences, also assisted in the research.

The National Eye Institute funded the work.

Wendy Lawton | EurekAlert!
Further information:
http://www.brown.edu

Further reports about: Brain Optic Visual walk

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>