Scientists in Israel have taught goldfish an unusual way to reach a target — by driving a small robotic car on dry land.
Six goldfish, regardless of their weight and size, took part in the experiment and were taught to drive in 30-minute sessions, conducted three times a week, every two days. The experiment was led by researchers at the Ben-Gurion University of the Negev. They wanted to see if goldfish's ability to navigate (导航) depends on their natural environment, or if they could navigate even under very unusual conditions.
To test the goldfish, the researchers created a special robotic car that could drive forward, backward, and from side to side. The scientists called the car a Fish Operated Vehicle (FOV).
Goldfish was placed inside a water tank on the FOV. Using a special system, the car tracked where the goldfish was and what direction it was swimming in. The FOV would then automatically move in the same direction. To prevent the goldfish from getting stuck in barriers such as walls, researchers equipped the car with lidar (激光雷达). The researchers tested them by placing the car in a small room with a pink target on one side — that was where the fish were supposed to arrive. The fish were rewarded with food when achieving the task.
The fish did indeed learn to drive the FOV, becoming more skillful in its operation over time both in terms of achieving tasks and in the time taken to complete that task. The researchers wanted to check that the fish weren't just memorizing a set of movements to earn a reward, so they repeated some tests with a new starting position or added other targets that were a different color. They found the goldfish were able to deal with those changes.
Though the experiment showed that the fish were able to navigate to a target, it's not likely that the fish knew they were controlling a car. The researchers say that in the future it may be possible to change the FOV to test these ideas.