The first test used a simple maze. In it, an animal had to make one choice: Go right — or left. Food is alternately placed on the left and the right. A sea lion, healthy or not, quickly learns this simple pattern, easily finding food again and again. A healthy sea lion will follow the pattern even if there is a small delay — say, a researcher puts a board at the front of the maze for seven seconds. But sea lions that had damage in the right hippocampus had trouble remembering the pattern and finding the fish.