Mirror reflection or real image: Does past mirror experience influence a dog's use of a mirror?

Abstract

Abstract Dogs can use a mirror appropriately to solve a task, but their response seems to depend on their habituation to the mirror beforehand. It seems that there is a relationship between behavior in looking at a mirror and the ability to use the mirror, but the interaction between the presence of a person and the time dogs spend looking in the mirror when confronted with a task has not been reported. Our aim was to investigate 2 factors: the dog's response to a person's reflection in a mirror or to the real person positioned in the same apparent position as the reflection as well as the time spent by the dog looking in the mirror before and after the person was present. Nine pet dogs participated and were categorized into 2 groups: a mirror-experienced group (EG) and a no-experience group (NEG). The EG had participated in a mirror test before the study. Two types of mirror—a whole mirror and a half mirror—were used. A familiar woman was positioned on the far side of an opaque barrier when the whole mirror was presented or behind a clear panel when the half mirror was presented. Both the time taken for the dog to reach the person and the dog's behaviors in reaching the person were recorded. The test was performed 20 times for each type of mirror for each dog. Dogs succeeding more in than 17 of 20 trials were considered to have the ability to use the mirror. Only 5 of 9 dogs reached this criterion in the half mirror session, although all dogs achieved the criterion in the whole mirror session. The time taken to reach the stimulus person differed between dogs in the 2 mirror-type sessions. However, the time spent looking in the mirror differed only within the EG. These results suggested that past experience with a mirror affected the dogs' ability to solve mirror tasks.