Psychology Student at Ashoka Asks — Can Fish Do Math?

Shashwat Goyal, Class of 2020, from the BioSoc

The recent introduction of Biology in the Ashokan curriculum might indicate that it’s the new kid in the playground, but that’s not exactly true. Research in bio-psychology or more commonly, cognition, is already a part of Ashoka’s research culture. For his research proposal, Dhairyya Singh, a fourth-year psychology major, has dared to ask the question — Can zebrafish do math?

His thesis proposal asks, “Do zebrafish have the ability to learn how to count small numbers based on associative learning?” Put in simple language, his experiment attempts to explore the possibility of zebrafish being able to count small quantities (viz 1, 2, 3, 4) using a technique that teaches the subject that if two things occur together, they are associated.

Dhairyya’s experiment will use a method in which the fish earn rewards for learning the association between the number of food pellets and the number of vertical lines. The fish will “choose” one of the two groups of lines . Two groups of one and two lines will be displayed to the fish on opposite sides of a T-shaped tank. Which arm displays how many lines will be randomized using a computer program. The fish will get food pellets equal to the number of lines displayed in the arm it swims into; the fish choosing one of the two groups of lines is indicated by where it chooses to be in the tank.

The idea is that if trained enough, the fish will learn that the number of lines equal the number of pellets given to them. Then they will be shown three and four lines on opposite sides of the T-shaped tank. If they have basic counting cognition, then they will choose the side with four lines significantly more than the side with three lines, having learnt that four lines means more food than three lines.

While this experiment may seem very simple on the face of it, it actually requires extensive setups and protocols in place. The fish must be given 40 minutes to get acclimatized to the T-shaped testing tank and the rectangular housing tank. They must be switched between tanks with a hasty disposition, as any amount of time out of water causes risks of brain damage. This will cause reduced cognitive ability and hence confound the results of the experiment. Their appetite must be measured, to ensure that they don’t resist eating the pellets during the experiment due to lack of hunger.

One might ask how he chose to research such an obscure topic and what we gain from researching it. Well, it’s not as obscure a topic as it may seem. As Dhairyya puts it, “My main reasons for choosing to look at this question include the fact that we know very little about the numerical abilities of most organisms, and we know especially little about how the brain generates the ability to do math. Exploring the question of whether zebrafish can count allows us to get a foothold into this problem”

Furthermore, research in the cognitive abilities of teleost fish (a group of fish to which the zebrafish belongs), conducted in the past, showed that four out the five species tested have the ability to discriminate between two groups of objects, up to a ratio limit of 0.67 (for example 2 v. 3 objects). The only species which didn’t show this ability, however, was the zebrafish. The researchers stated the results are not because of the fish’s lack of ability but rather the incompatibility of experimental conditions and tasks with the fish. This means that we still know very little about the numerical abilities of zebrafish, and they are open for exploration.

Another advantage of working with zebrafish is that it is easy to image their neural tissue. Larval zebrafish have transparent heads and this allows for the non-invasive mapping of their neural tissue (that’s fancy talk for brain scans) when there is brain activity. This kind of neural imaging will throw light not only on the evolution of mathematical ability in animals (including us), but perhaps, intelligence in general.

This experiment very clearly shows that Biology as a subject is already alive and kicking on our campus. However, with the official establishment of Biology as a subject in the curriculum, there’s no doubt that students can look forward to more serious and interesting research.