Fish and rays were taught to add and subtract

The authors of the new work created special cameras, they were divided into two screens. Each showed different

images, for example, five dots on one and three on

friend.

Further, the fish could choose one of their sides and received or did not receive a reward. Over time, they learned to associate the visual stimuli on the screens with the desired outcome.

Then the task became more difficult:At first, the authors showed figures of different colors, then they had to memorize them in 5 seconds. Then the gates were opened, and the fish had to choose between two doors with screens: one with an additional figure and the other with one less figure.

Blue meant addition and yellow meant subtraction.If there were three blue shapes in the image, then you had to add one to three and select the image with four shapes. Then they received a reward.

If two figures in the original image wereyellow, then the fish received a reward in the test area only if they swam to the image showing one figure - this was similar to the subtraction operation.

The tests were carried out with eight mbuna zebras and suchthe same number of slopes. As a result, six Mbuna zebras and three stingrays learned to count: they successfully answered questions about addition in 78 and 94% of cases, respectively. Subtraction was more difficult: the percentage of correct answers dropped to 69% and 89%, respectively.

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