Rats were required to swim to a hidden platform in order to escape from a M
orris pool, after they had been exposed to the landmarks around the pool by
swimming to a platform that had a beacon attached to it. The platform occu
pied a different place for the test trials than for the preexposure trials.
Escape from the pool was facilitated if the landmarks remained in the same
place throughout preexposure, but if their positions were changed during p
reexposure, then subsequent escape from the pool was disrupted (Experiment
2). Escape learning was also disrupted if the rats were placed on the platf
orm for their preexposure treatment (Experiment 3). The results indicate th
at the associability of the cues around a Morris pool may be enhanced when
they are in a stable spatial relationship with the platform. throughout eac
h preexposure session.