A new study published in the journal Science Advances shows that honeybees (Apis mellifera), with a miniature brain, can be taught to recognize colors as symbolic representations for addition and subtraction, and they can use this information to solve arithmetic problems.
Howard et al show that honeybees can learn to use blue and yellow as symbolic representations for addition or subtraction. In a free-flying environment, individual bees used this information to solve unfamiliar problems involving adding or subtracting one element from a group of elements. Image credit: Ralph.
Solving maths problems requires a sophisticated level of cognition, involving the complex mental management of numbers, long-term rules and short term working memory.
Building on their finding that honeybees can understand the concept of zero, RMIT University’s Dr. Adrian Dyer and his colleagues set out to test whether honeybees could perform arithmetic operations like addition and subtraction.
“Numerical operations like addition and subtraction are complex because they require two levels of processing,” Dr. Dyer said.
“You need to be able to hold the rules around adding and subtracting in your long-term memory, while mentally manipulating a set of given numbers in your short-term memory.”
“On top of this, our bees also used their short-term memories to solve arithmetic problems, as they learned to recognize plus or minus as abstract concepts rather than being given visual aids.”
“Our findings suggest that advanced numerical cognition may be found much more widely in nature among non-human animals than previously suspected.”
“If maths doesn’t require a massive brain, there might also be new ways for us to incorporate interactions of both long-term rules and working memory into designs to improve rapid AI learning of new problems.”
The team’s experiments involved training individual honeybees to visit a Y-shaped maze.
The researchers used 14 free-flying honeybee foragers. All bees were marked with a colored dot on the thorax to identify individuals.
They received a reward of sugar water when they made a correct choice in the maze, and received a bitter-tasting quinine solution if the choice was incorrect.
Honeybees will go back to a place if the location provides a good source of food, so the bees returned repeatedly to the experimental set-up to collect nutrition and continue learning.
When a bee flew into the entrance of the maze they would see a set of elements, between 1 to 5 shapes.
The shapes were either blue, which meant the bee had to add, or yellow, which meant the bee had to subtract.
After viewing the initial number, the bee would fly through a hole into a decision chamber where it could choose to fly to the left or right side of the maze.
One side had an incorrect solution to the problem and the other side had the correct solution of either plus or minus one. The correct answer was changed randomly throughout the experiment to avoid bees learning to visit just one side of the maze.
At the beginning of the experiment, bees made random choices until they could work out how to solve the problem.
Eventually, over 100 learning trials that took 4 to 7 hours, bees learned that blue meant +1, while yellow meant -1. The bees could then apply the rules to new numbers.
“Our findings show that the complex understanding of maths symbols as a language is something that many brains can probably achieve, and helps explain how many human cultures independently developed numeracy skills,” said study first author Scarlett Howard, a PhD researcher at RMIT University.
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Scarlett R. Howard et al. 2019. Numerical cognition in honeybees enables addition and subtraction. Science Advances 5 (2): eaav0961; doi: 10.1126/sciadv.aav0961
