Aging affects the cognitive abilities of dogs, as a recent study by the Clever Dog Lab of the Messerli Research Institute at the Vetmeduni Vienna shows. A team of behavioural scientists studied dogs of different ages working on a specially designed touchscreen computer and discovered that although all dogs were capable of learning, older dogs learnt more slowly than younger ones. No age-related differences were found regarding long-term memory. The results were published in the journal Age.
The effect of aging on cognitive processes such as learning, memory and logical reasoning have so far been studied almost exclusively in people.
Using a series of touchscreen tests, Lisa Wallis and Friederike Range of the Messerli Research Institute at Vetmeduni Vienna have now studied these domains in pet dogs of varying ages. The study was conducted with 95 Border Collies ranging in age from five months to 13 years. The dogs regularly came to the Clever Dog Lab on the Vetmeduni Vienna campus accompanied by their owners to conduct the tests on a touch-sensitive monitor.
“Border Collies have a reputation for being fast learners. They were bred over generations for characteristics that are important in shepherding. In recent years they have become a popular breed of pet dog, probably because they are so easy to train. This is why we had access to enough test animals from this breed,” explains study director Friederike Range.
The dogs were divided into five age groups and tested in four tasks. These were designed to test three cognitive abilities: learning, logical reasoning and memory.
Older dogs learn more slowly and exhibit lower cognitive flexibility
The tests revealed differences in cognitive ability depending on the age of the dogs. The first part required the animals to learn to correctly select four from a total of eight abstract pictures on a touchscreen. The dogs were shown two pictures on the screen at a time. One picture had a positive association – the dogs were rewarded with a food treat for touching this picture – while the second picture had a negative association – touching this picture did not result in a treat but in a time-out. The four “positive” pictures were presented in different combinations with the “negative” pictures.
“Older dogs required more trials than younger ones before they were able to solve the task correctly. The test also showed that older dogs are less flexible in their way of thinking than younger ones. As in people, older dogs find it more difficult to change old habits or what they have learned,” explains Lisa Wallis, the study’s first author.
Logical reasoning improves with age
After the Border Collies reached a learning criterion they were again shown two pictures on the touchscreen. This time, one of the pictures was new for the animals. The second one was familiar from the previous test where it had a negative association. The dogs should identify it as the “wrong” one. The novel picture would therefore be the “correct” one. Hence, the dogs had to choose through inference by exclusion.
“The older the dog, the better it performed, while younger dogs were unable to master this task. This is probably due to the fact that older dogs more stubbornly insist on what they have learned before and are less flexible than younger animals,” says Range.
Long-term memory for touchscreen stimuli is not affected by age
Six months after the first learning tests, the researchers repeated the touchscreen trials using the same eight abstract pictures as before in order to test the dog’s long-term memory skills. The test revealed no significant age differences. Nearly all dogs remembered the correct pictures as positive.
The results of this study provide measures associated with normal cognitive aging in Border collies, and thus could be used as a basis for breed comparisons as well as early recognition and treatment of certain cognitive deficits.
About this learning and memory research
Source: Susanna Berger – University of Veterinary Medicine, Vienna Image Source: The image is credited Lisa Wallis/Vetmeduni Vienna Original Research: Full open access research for “Aging effects on discrimination learning, logical reasoning and memory in pet dogs” by Lisa J. Wallis , Zsófia Virányi, Corsin A. Müller, Samuel Serisier, Ludwig Huber, and Friederike Range in Age. Published online January 4 2016 doi:10.1007/s11357-015-9866-x
Aging effects on discrimination learning, logical reasoning and memory in pet dogs
In laboratory dogs, aging leads to a decline in various cognitive domains such as learning, memory and behavioural flexibility. However, much less is known about aging in pet dogs, i.e. dogs that are exposed to different home environments by their caregivers. We used tasks on a touchscreen apparatus to detect differences in various cognitive functions across pet Border Collies aged from 5 months to 13 years. Ninety-five dogs were divided into five age groups and tested in four tasks: (1) underwater photo versus drawing discrimination, (2) clip art picture discrimination, (3) inferential reasoning by exclusion and (4) a memory test with a retention interval of 6 months. The tasks were designed to test three cognitive abilities: visual discrimination learning, logical reasoning and memory. The total number of sessions to reach criterion and the number of correction trials needed in the two discrimination tasks were compared across age groups. The results showed that both measures increased linearly with age, with dogs aged over 13 years displaying slower learning and reduced flexibility in comparison to younger dogs. Inferential reasoning ability increased with age, but less than 10 % of dogs showed patterns of choice consistent with inference by exclusion. No age effect was found in the long-term memory test. In conclusion, the discrimination learning tests used are suitable to detect cognitive aging in pet dogs, which can serve as a basis for comparison to help diagnose cognition-related problems and as a tool to assist with the development of treatments to delay cognitive decline.
“Aging effects on discrimination learning, logical reasoning and memory in pet dogs” by Lisa J. Wallis , Zsófia Virányi, Corsin A. Müller, Samuel Serisier, Ludwig Huber, and Friederike Range in Age. Published online January 4 2016 doi:10.1007/s11357-015-9866-x