Negative patterning in the spatial domain.

In three experiments, animals were required to learn about the presence or absence of a hidden platform in a swimming pool. This was determined with reference to different patterned landmarks. In Experiment 1, the presence of a spotted or a striped cue indicated the position of the platform, while the combination of patterns, a half-spotted and half-striped cue, predicted the absence of the goal (i.e., negative patterning). In Experiment 2 the task was redesigned to better represent a locale navigation task. Rats received the same discrimination task, but it took place in an equilateral triangle with landmarks positioned on the walls of the arena. The hidden platform (if present) was located in one corner of the triangle. Experiment 3 used a more complex negative patterning discrimination in the triangular swimming pool to help dissociate between the unique cue and configural associative learning theories. Experiment 1 and 2 provides the first instance of negative patterning in a spatial task, while Experiment 3 provides initial evidence that some rats may represent compound stimuli in a way explained by the unique cue theory of associative learning. This begins to elucidate the underlying of associate principles that guide learning in the spatial domain.