2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Ethologists have found that bees are able to match symbols with numbers and vice versa. As reported in Proceedings of the Royal Society B, insects have learned to correctly correlate a certain number with a symbol (the sign of N and an inverted T), or vice versa, a symbol with a number. However, the bees were unable to independently "reverse" the association and correlate the symbol with the number, if they had previously been taught to associate the number with the symbol.
Some animals are able to associate the number of objects with their symbolic representation. Pigeons can correctly recognize a number corresponding to a number of objects and point to it. Chimpanzees, gray parrots and rhesus monkeys are capable of correlating symbols with the number. For example, Alex the Grays learned the names of the numbers and mastered addition, while the chimpanzees memorized Arabic numerals and learned how to place them in order.
Honey bees (Apis mellifera) are often used in insect cognitive research. As it turned out, they are able to learn some concepts, in particular "right-left" or "more-less", and can also count to four. Australian and French biologists led by Adrian Dyer of Melbourne Queen's University of Technology have also shown that bees can recognize zero and that they can be taught to add or subtract using colors as representations.
In a new study, Dyer and his colleagues decided to go further and test whether bees are able to associate a number of objects with symbols, and vice versa. To train the insects, the scientists used a single-entry Y-shaped maze, traditional for selection experiments. The experimental animal (in this case, the bee) enters the labyrinth through a single passage, and then it needs to make a choice at the fork, passing through one of the two arms to the exit.
Next to the entrance, the authors placed a stimulus picture on which either symbols were depicted: the letter "N" or an inverted "T", or two or three figures - the number. In the inner room of the labyrinth, the bee had to choose one of two pictures with the correct or incorrect answer (on which, depending on the training being carried out, there were either figures or letters) and exit through the appropriate exit. If the insect chose the correct answer, it was given a drop of sugar syrup, if the wrong one - a drop of a bitter solution of quinine. The experiments involved 20 bees (10 in each group), which passed 50 training tests.
In the main experiment (series of 10 tests), the bees had to match either a symbol with one of two sets of figures, or a set of figures with one of two symbols. In addition, the authors tested whether insects were able to "reverse" associations. That is, can the bees who have been trained to associate a symbol with the number of figures independently (without prior training) correlate a set of figures with one of the two symbols, and vice versa.
Experiment scheme. Above: Matching the symbol to the number of shapes. Before entering, there is a picture with a symbol that needs to be correlated with one of the pictures with figures. In the labyrinth on the right there is a picture with the correct answer, on the left - with the wrong answer. Bottom: Matching the number of shapes to one of two characters. On the right in the maze there is a picture with the correct answer, on the left - with the wrong one.
It turned out that honey bees can be taught to associate symbols with the number of figures and the number with the symbol. Insects from the first group, which were trained to associate a symbol with the number of figures, on average, gave correct answers in 65 percent of cases (p = 0.003). Bees from the second group, which were taught to correlate a certain number of figures with one of the two symbols, answered correctly in 62 percent of cases (p = 0.029), that is, more often than randomly.
But the bees were unable to “reverse” the associations. They could not themselves learn to associate a symbol with the number of figures if they were trained to correlate the number of figures with one of the two symbols, and vice versa. "This suggests that the processing of numbers and the understanding of symbols occurs in different areas of the bee's brain, similar to how separate processing of information occurs in the human brain," says lead author Scarlett Howard of the University of Toulouse.
As the authors note, the results of the study do not allow bees to be placed on a par with gray parrots, chimpanzees and macaques. But they do provide a better understanding of how insects' brains work, and that vertebrates are not the only ones with the ability to match numbers and symbols.
Bees are capable of more than just numbers. As the researchers found, social insects - bees and wasps are able to recognize human faces, and they do it in the same way as humans, perceiving the whole face.