Same-different learning of odour stimuli in dogs.

The performance of detection dogs relies on their ability to detect and alert to variations of the stimuli upon which they have been trained. As such, research has tended to focus on understanding the likelihood of generalising beyond a trained stimulus set. However, it remains unclear which stimuli dogs perceive as the ‘same’ or ‘different’ to others. Understanding this perception would allow the creation of appropriate training aids to improve the performance of working dogs. The aim of this study was to establish whether dogs were capable of same-different concept learning with odours and whether they could generalise this learning to a novel stimulus set. Dogs were presented with two odours simultaneously and trained to give one indication behaviour if the samples were the same, and an alternative indication if they were different. Four of the ten dogs tested were able to meet the learning criteria, indicating that they could learn the task with the training stimuli. However, none were able to generalise the concept to a new stimulus set. The failure of the dogs to generalise the same-different learning to novel stimuli suggests that the procedure used, while showing some promise, may not be the best approach to assess how dogs perceive odours in relation to each other.