Using owls as a model, a new research study reveals the advantage of stereopsis, commonly referred to as stereovision, is its ability to discriminate between objects and background; not in perceiving absolute depth. The findings were published in a recent Journal of Vision article, Owls see in stereo much like humans do.
The purpose of the study, which was conducted at RWTH Aachen (Germany) and Radboud University (Nijmegen, Netherlands), was to uncover how depth perception came into existence during the course of evolution.
"The reason why studying owl vision is helpful is that, like humans, owls have two frontally placed eyes," said author Robert F. van der Willigen, PhD, of Donders Institute for Brain, Cognition and Behavior at Radboud. "As a result, owls, like humans, could appreciate the 3-dimensional shape of tangible objects through simultaneous comparison of the left and right eye."
van der Willigen studied two trained barn owls (Tyto alba) by conducting a series of six behavioral experiments equivalent to those used on humans. He used computer-generated binocular random-dot patterns to measure stereo performance, which showed that the owl's ability to discriminate random-dot stereograms is parallel to that of humans despite the owl's relatively small brain. The results provided unprecedented data on stereovision, with findings that debunk the long-held consensus that the evolutionary advantage of seeing in stereo must be depth vision.
He contends the findings demonstrate that while binocular disparity, the slight difference between the viewpoints of the right and left eyes, does play a role in perceiving depth, it allows owls, like humans, to perceive relative depth rather than absolute distance. "It is useful, therefore, not so much in controlling goal-directed movements as it is in recognition."
In looking at future studies, van der Willigen hopes that scientist will consider that human or primate vision is not the only way to examine the stereovision experience. "My present work on the owl highlights underappreciated, but fundamental aspects of stereopsis," he says. "Nonetheless, final proof should come with behavioral demonstration of equivalent stereoscopic abilities in animals other than the owl. Hopefully, my current work will encourage scientists to investigate other animal species."
Association for Research in Vision and Ophthalmology: http://www.arvo.org
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
I answers my question. "What purpose of stereo vision?"
Mother deer rushed towards the infant distress calls of seals, humans and even bats, suggesting that these mammals share similar emotions
In the forests of eastern Australia, a squadron of social spiders faces off against an army of the world's most dangerous ants in a pitched battle for survival
Contrary to some earlier projections, the world's population will soar through the end of the 21st century thanks largely to sub-Saharan Africa's higher-than-expected birth rates, United Nations and other population experts said on Thursday.
Archaeologists got to the root of an ancient hairstyle when they unearthed a 3,300-year-old body with 70 hair extensions
A major international study finds that killings among chimpanzees result from normal competition, not human interference.
Clownfish travel hundreds of kilometres, but it is the larvae rather than the adults that migrate
U.S. government researchers working with divers and sonar equipment have located the wrecks of what they dubbed "forgotten ghost ships" in waters just outside San Francisco's Golden Gate strait.
"It's spooky," a Clearwater, Fla., fisherman said, comparing the toxic algae bloom to "boiled red Georgia clay"
Physicist Danielle Bassett has been awarded a MacArthur Fellowship based on her work studying the human brain. She talks with Melissa Block about the advances it may lead to.
A team of researchers are using multispectral imaging to uncover hidden text on a 1491 Martellus map, one of the most important maps in history. Lead researcher Chet Van Duzer thinks the discoveries will allow historians and scholars to see just how the map influenced cartography in its time.