Control of spatial behavior by an unstable landmark

In 5 experiments rats were required to escape from a pool of water by finding a submerged platform that varied in position from session to session. The platform was in a fixed direction and at a fixed distance from a landmark that was located in the pool. Experiments 1-3 revealed that the landmark was used as a reference point for information about the direction and the distance of the platform. In Experiments 4 and 5, the landmark and platform remained in the same place for one group but moved as one from session to session for another. Both groups were then placed in the pool for periods without the landmark and platform. Testing with the landmark then revealed that it controlled more accurate searching by the group trained with the unstable than with the static landmark. The results do not support the proposal that animals are more likely to use a static than a moving landmark as a reference point for finding a goal.