Visual recognition of mirror, video-recorded, and still images in rats

Several recent studies have claimed that rodents have good visual recognition abilities. However, the extent to which rats can recognize other rats and distinguish between males and females using visual information alone remains unclear. In the present study, we investigated the ability of rats to visually recognize mirror, video-recorded, and still images and to discriminate between images of males and females. Rats were tested in a place preference apparatus with a mirror, a video-recorded image of a rat, or a still image of a rat at one end. The data were assessed using t-test with Bonferroni correction. Male and female rats spent significantly more time in the mirror chamber and the video-recorded image chamber than in their respective blank chambers (P