Praying Mantises Sport the World's Smallest 3D Glasses
Experiments with praying mantises fitted with tiny 3D glasses eventually could lead to a new generation of more efficient robots or to other as yet unimagined applications. Mantises appear to be physically optimized for 3D vision. Their triangular heads maximize the 3D vision baseline; they have a binocular overlap of more than 70 degrees; and they have forward-facing fovea.
What might be the world's smallest 3D glasses have been developed for praying mantises.
People, horses, falcons, cats, monkeys and even toads have 3D vision -- but until 1983, everyone thought that invertebrates didn't, because their brains were so small and simple. That year, Samuel Rossel of the University of Zurich in essence said that mantises had 3D vision.
Now Jennifer Read of Newcastle University in the UK has launched a five-year research program to study mantis 3D vision.
The research, publicized by the university last week, aims to establish whether mantis 3D vision is capable of only range-finding or also can break camouflage. During World War 1, 3D photos made it easier to identify camouflaged military structures.
The Newcastle study will explore how mantises, with their tiny brains, can process 3D images. The praying mantis' brain has about one million neurons compared to tens of billions in the human brain.
The research could lead to development of a machine 3D algorithm that would take binocular video streams as input for translating into actions. Such an algorithm might be simpler than existing ones, while outperforming them.
"Usually simpler is better, but only if the result is equivalent to less simple," Tom Defanti, director of visualization at the California Institute for Telecommunications and Information Technology at the UCSD, told TechNewsWorld.
How the Experiment Will Be Performed
The 3D glasses will be attached to a mantis' face with beeswax. The mantis will then be put in front of a 3D computer screen and shown a moving image for it to strike.
Two high-speed cameras, recording at 1,000 frames a second, will record the mantis' position from below and from the side. The cameras interface with a computer, which will download the images and analyze the data. The researchers developed automated 3D display, data collection and analysis technology for the experiment.
Extracellular activity in the mantis' nervous system will be recorded, with the researchers using silver wire electrodes to measure the electrical spikes produced by a subset of neurons. [*Correction - May 1, 2014]
More on the 3D Glasses
The 3D glasses are actually circular polarizing filters, because insect eyes are sensitive to linear polarization but not circular polarization. [*Correction - May 1, 2014]
These filters are the same as those used for 3D TVs and computer monitors.
A spokesperson for the Newcastle University research program was not immediately available to provide further details.
The Things that Mantises Do
Mantises appear to be physically optimized for 3D vision, Read stated.
Their triangular heads maximize the 3D vision baseline; they have a binocular overlap of more than 70 degrees; and they have forward-facing fovea -- that part of the eye that sees things in great detail -- in their eyes.
Mantises previously have inspired technological developments. They tilt their heads left and right when they look, apparently to obtain depth perception, and this led to the development of a mathematical model for depth estimation, the mantis head camera.
Implications of Simpler Algorithms
"In computing, the more pixels and attributes you compare, the more accurate and complex the algorithm," Jim McGregor, principal at Tirias Research, told TechNewsWorld.
Generally speaking, a simpler algorithm would lead to faster processing, lower power consumption and longer battery life -- and possibly the ability to process more data with a greater level of accuracy, McGregor said. Processing speed and accuracy could play a critical role in robotics.
It's All in the Eyes
Mantises' eyes are disproportionately large, so it might be that the 3D images are being processed in them rather than in the insects' brains.
"This is very likely, because it would speed processing significantly," Rob Enderle, principal analyst at the Enderle Group, told TechNewsWorld.
If that is the case, it could provide another option for equipping robots to view 3D, and allow them to get their job done sooner, he speculated. It would "allow a more modular approach to a variety of vision problems."
Still, mantis eyes can't match up to those of the mantis shrimp, which apparently can see ultraviolet and infrared, and view two forms of polarized light. They see in 3D and their visual system has been compared to a satellite.
*ECT News Network editor's note - May 1, 2014: Our original published version of this story incorrectly implied the experiment had already taken place.
*ECT News Network editor's note - May 1, 2014: Our original published version of this story incorrectly stated that insect eyes are sensitive to circular polarization and not linear polarization. In fact, it's the other way round -- insect eyes are sensitive to linear polarisation but not circular.