How to turn the corner: Discrimination of path shapes in rats

The internal representation of a path shape is an element that constructs an internal representation of an entire route or environment. In the present study, we examined the ability of rats to discriminate path shapes. The rats learned to discriminate between an oval-shaped runway and a square-shaped one and to respond to one of two response boxes on the two sides of the runways. After the learning sessions, we tested which of the inner and outer walls the rats used as cues for discrimination using different wall shapes. The results suggest that the rats used the shape of the inner walls for the discrimination. Subsequently, the learning sessions, in which different shapes of the inner and outer walls were used, continued. There was a tendency for the rats to show better performance when the shape of the inner walls was congruent with the rule in the original learning, suggesting again that the rats used the shape of the inner wall for the discrimination. In addition, similar results were obtained when the task was conducted in the dark, suggesting that rats can discriminate path shapes using non-visual information.