Prof hopes this fish story offers insights into human-decision making

David Pick spends a lot of time watching animals.

Chair of the Psychology Department, Pick researches animal behavior in order to understand decision making. His current subject is a group of goldfish.

Before goldfish, Pick initiated a field experiment with horses. Painted panels, one gray and one blue, were positioned six feet apart in a horse pasture. Each time a horse chose the blue panel, it could indulge in some hay. When it chose the gray panel, the horse was given a short time-out in its stable with no hay.

There was only one problem: “Horses don’t care about color,” said Pick. 

He is hoping goldfish are different.

Pick’s goal is to determine if there is continuity in decision making between humans and animals lower on the phylogenetic scale. 

“Humans are at the top of the phylogenetic scale while horses are below us and goldfish are a lot further down,” Pick explains. 

His experiment focuses on one particular kind of decision making, which is making a choice between something you are very familiar with as opposed to something you are not at all familiar with.

The advantage of goldfish is they are “more advanced to color,” Pick said.

His experiment with goldfish is operated by an apparatus controlled by a credit card-sized computer that uses Python, a high-level programming language mainly used in robotics. The Raspberry Pi computer controls two LED lights in the goldfishes’ tank, one LED is colored, the other is not. 

When a goldfish swims up to the colored LED, the Raspberry Pi uses infrared sensors to pick up on the response, and a tiny fish pellet is dispensed if it chooses the correct one. When the infrared sensor detects an incorrect response from the fish, the apparatus shuts off the lights in the tank for one minute, and dispenses no food pellet.

The apparatus records all incorrect and correct responses, and a fish can engage in as many trials as it wants each day, and produce the normal amount of food it would eat in a day.

“The fish is getting fed its daily ration pretty much automatically, and the data is being collected automatically,” said Pick. 

Several students are also involved in this experiment. Before the computer was introduced, students were manually feeding the fish and manually controlling the lights and food pellets. 

But even the goldfish have posed some problems. 

Like any animal, they have some kind of personality. One of the goldfish is shy and hides in the corner of the tank, not participating in the experiment. Another is overly-excited and swims around a lot, making it challenging for it to focus on the LEDs.

At the end of Pick’s experiment when all the data is collected, the goldfish will be adopted as pets by the student researchers and caretakers.