The team, from the university’s Department of Computer Science working alongside international collaborators, published its study in the journal Proceedings of the Royal Society B.
This latest insight could be used to design more sophisticated machines based on the brains of animals, researchers believe, in addition to providing a new, alternative blueprint for testing numerical cognition in animals.
Determining how different brains, especially those with a miniature brain, solve numerical tasks can provide valuable insight into the evolutionary roots of cognition. The ability to use numbers is a powerful cognitive capacity of humans, but replicating their full sophistication via AI is not possible with current approaches.
Through an approach commonly used to test numerical cognition in bees and other animals, the Sheffield team discovered that honeybees can discriminate between placards displaying different numbers of elements without their brains having to process numerical data.
According to the researchers, honeybees were individually trained to identify the placards: some honeybees learned to find a sugary reward at the placards that had the most shapes on display, while others learned to find the sugary treat at the placards showing the fewest shapes.
To determine if the honeybees used non-numerical cues, researchers said they were then tested with two pairs of placards that contained the same numbers of shapes but differed in edge length, convex hull and spatial frequency. None of the placards had a sugary treat and if the bees used numerosity, they would have flown to each placard equally in search of a reward.
Results showed that bees trained to find placards with the highest number of shapes still flew to signs with the highest level of continuous variables and bees that were trained to find placards with the lowest number of shapes still flew to the signs with the lowest level of continuous variables, ignoring numbers. This suggested the honeybees responded to continuous cues on the shapes and not the number of elements.
To further test the hypothesis, the team showed the bees placards with visual cues opposite to the number of shapes on the placards: for example, placards with three shapes on display but a lower spatial frequency than the placards with two shapes.
In these tests, honeybees behaved in a reverse manner to what would be expected if they had learned numerosity, the team confirmed.
“The results of our work suggest that the ability to distinguish items based on continuous magnitudes, i.e properties such as density or total area of items, might be more basic and perhaps evolutionarily older than the ability to process numbers,” said Dr Cwyn Solvi, a co-author at Macquarie University, Australia.
To determine how efficient the strategy was for bees, the researchers also said they created a model based on known details of the honeybee brain. The model was able to solve several other similar numeric-based tasks without need for number processing.
Lead author of the paper, Dr HaDi MaBouDi, said: “This doesn’t mean that bees or other non-verbal animals can’t understand numbers, but it does suggest that animals use non-numeric properties to solve the maths problems they often face if such information is available. However, we hope that our study provides insight into better methods of exploring mathematical cognition in animals.”