Spatial decisions in rats based on the geometry of computer-generated patterns

Animals often demonstrate the ability to use the geometric configuration of multiple landmarks for orientation in the environment. We developed a new behavioral task using a computer screen for presentation of visual stimuli allowing the rats to make navigational decisions in real space according to the geometric configuration of external virtual patterns (designed as a possible representation of this space). The rats were placed in a Skinner box with four nosing holes in the transparent front wall through which the computer screen was visible. They were trained in successive phases: first the visual stimulus displayed on the screen directly marked the rewarded nosing hole, then the displayed stimuli were reduced in size or displaced, thus disconnected from the response space. The results suggested that rats were able to use the geometric configuration of stimuli presented on the computer screen for navigational decisions in real space.