Potentiation and overshadowing between landmarks and environmental geometric cues

Abstract

Rats were required in three experiments to find one of two submerged platforms that were situated in the same pair of diagonally opposite corners of a rectangular grey swimming pool. The experimental groups were trained with landmarks, comprising A4 cards attached to the walls, located in the corners containing the platforms. For the control groups, the landmarks were situated in the corners containing the platforms for half of the trials, and in the other corners for the remaining trials. Learning about the positions of the platforms with reference to the shape of the pool was overshadowed in the experimental groups when the landmarks were white, and enhanced when the landmarks were black. A fourth experiment assessed whether geometric cues influenced the control acquired by the landmarks. As in the previous experiments, the presence of the geometric cues overshadowed learning about the landmarks when they were white, but enhanced learning when the landmarks were black.

Figure 1

Mean (± SEM) escape latencies (left-hand panel) and mean percentage of correct choices (right-hand panel) for the experimental and control groups of Experiment 1. B and W indicate the color of the landmarks each group received during training.

Figure 2

Mean (± SEM) percentage of time spent in the correct and incorrect zones during the geometry (left-hand panel) and landmark (right-hand panel) tests for the experimental and control groups of Experiment 1. B and W indicate the color of the landmarks each group received during training.

Figure 3

Mean (± SEM) escape latencies (left-hand panel) and mean percentage of correct choices (right-hand panel) for the experimental and control groups of Experiment 2a.

Figure 4

Mean (+ SEM) percentage of time spent in the correct and incorrect zones during the geometry test for the experimental and control groups of Experiment 2a.

Figure 5

Mean (± SEM) escape latencies (left-hand panel) and mean percentage of correct choices (right-hand panel) for the experimental and control groups of Experiment 2b.

Figure 6

Mean (+ SEM) percentage of time spent in the correct and incorrect zones during the geometry test for the experimental and control groups of Experiment 2b.

Figure 7

Mean (± SEM) escape latencies (left-hand panel) and mean percentage of correct choices (right-hand panel) for the experimental and control groups of Experiment 3. B and W indicate the color of the landmarks each group received during training.

Figure 8

Mean (+ SEM) percentage of time spent in the correct and incorrect zones during the landmark test for the experimental and control groups of Experiment 3. B and W indicate the color of the landmarks each group received during training.