Two months ago, I told you that bees could be trained to find land mines. Now, researchers from University College London (UCL) have shown that bees are able to solve complicated color puzzles. In their study, bees were trained to find artificial flowers containing a nectar reward and colored in blue. Then they removed the nectar and put at random artificial flowers illuminated by yellow, blue, yellow and green lights. But wherever the blue flowers were, the bees continued to select them even if there was no longer a reward. These findings may soon lead to the design of sophisticated visual systems for autonomous robots.
Here is the introduction of the UCL news release.
Bees have a much more sophisticated visual system than previously thought, according to a new UCL (University College London) study in which bees were able to solve complicated colour puzzles. The findings shed light on how brains resolve one of the most difficult challenges of vision -- namely, recognizing different surfaces under different colours of illumination -- by suggesting that bees solve this problem using their experience with meaningful colour relationships between objects in a scene.
Below is a photo of a bee searching for fake 'nectar' (sugar water) in a plastic 'flower' (Credit: UCL). And here is a link to a larger version (5.19 MB) of this picture.
National Geographic gives more details about the puzzle the bees had to solve.
To better grasp how bees operate in such complex lighting, [the two researchers, R. Beau Lotto and Martina Wicklein] set up a bumblebee puzzle. The duo built an array of 64 Plexiglas "flowers." The array was then divided into 4 panels of 16 flowers. In each panel, light filters gave four flowers different colors: ultraviolet yellow, blue, yellow, and green.
Lotto and Wicklein then placed a sugar solution at every blue flower. This trained forager bees to selectively visit the blue blossoms amid the riot of multicolored, plastic flowers.
Once trained, the bees were given what Wicklein, an expert on insect biology and behavior, describes as a "multiple-choice exam." The researchers rearranged the blossoms and removed all traces of the sugar solution.
And to their surprise, the bees returned to the blue flowers, even when exposed to new sets of light conditions.
For more information and pictures about this experiment called "the bee matrix," you can read a former UCL news release, Sight of the bumblebee.
The site of R. Beau Lotto's lab also contains links to demos and publications, but for the moment, some of these links are broken.
The research work should be published by the Proceedings of the National Academy of Sciences under the name "Bees encode behaviourally significance spectral relationships in complex scenes to resolve stimulus ambiguity," but it is not available online yet.
Finally, here is a last quote of National Geographic about an intermediate step between the live bees and future robotic systems with similar visual capabilities: virtual bees.
One of [Lotto's] students has already created a virtual bee computer program, like the matrix described in the study, that's populated with virtual bees. In the virtual system, the bees evolve their ability to use color relationships. Those that can pick out the blue flowers eat, live, and reproduce. Those that can't starve and die off. "In this next year we're trying to take those virtual robots into the real world," Lotto said.
Sources: UCL news release, October 31, 2005; Bethany Halford, for National Geographic News, November 1, 2005; and various web sites
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