Posted Date: August 20, 2015
Claudia Bensimoun discusses a recent study on stress and arousal in calm and hyper dogs and the effect on a dog's performance.
We've all wondered whether our dogs perform better under stress. What if they're subjected to high levels of stress or too little stress? Does this affect their performance? Are dogs similar to humans in that just the right amount of stress may affect their ability to perform? Researchers recently found that a little stress is beneficial to timid dogs; yet hyperactive dogs should not be subjected to even a little stress. When this happens they don't perform as well.
According to an article published in Science Daily on July 21, 2015 by researchers from Duke University and the University of Pennsylvania, extra stress and stimulation can be helpful to some dogs depending on their temperament. Mellow dogs do well with extra stress and stimulation, yet hyperactive dogs do not do well with the added stress. These findings were published in Animal Cognition.(Emily E. Bray, Evan L. MacLean, Brian A. Hare. Increasing arousal enhances inhibitory control in calm but not excitable dogs. July 2015.)
Dr. Emily Bray (University of Pennsylvania, Department of Psychology), Dr.Evan MacLean and Dr. Brian Hare, evolutionary anthropologists from Dukes Canine Cognition Center (DCCC) wanted to see if certain conditions that help dogs perform better need to be combined with a dog's temperament. Researchers found that dogs with a calmer temperament apparently have an edge and do well with a little extra stress in their environment.
"When you're taking a test, for example, it helps to be a little bit anxious so you don't just blow it off," said co-author Emily Bray via Science Daily. "But if you're too nervous, even if you study and you really know the material, you aren't going to perform at your best."
The researchers explained how if one undertakes a task that is not mentally demanding, it can become difficult to remain focused on the task for long. Humans tend to become bored. The same applies to dogs. Nonetheless, if there is too much of a challenge, or if stress levels are too high, some dogs may not perform as well, as would people in the same situation. The trick is to understand your dog and his temperament, and to fine-tune the right amount of stress.
Abstract From The Research Paper
According to the original research paper the abstract reads as follows:
"The emotional-reactivity hypothesis proposes that problem-solving abilities can be constrained by temperament, within and across species. One way to test this hypothesis is with the predictions of the Yerkes-Dodson law. The law posits that arousal level, a component of temperament, affects problem solving in an inverted U-shaped relationship: Optimal performance is reached at intermediate levels of arousal and impeded by high and low levels. Thus, a powerful test of the emotional-reactivity hypothesis is to compare cognitive performance in dog populations that have been bred and trained based in part of their arousal levels. We therefore compared a group of pet dogs to a group of assistance dogs bred and trained for low arousal on a task of inhibitory control involving a detour response. Consistent with the Yerkes-Dodson law, assistance dogs, which began the test with lower levels of baseline arousal, showed improvements when arousal was artificially increased. In contrast, pet dogs, which began the test with high levels of baseline arousal, were negatively affected when their arousal was increased. Furthermore, the dogs' baseline levels of arousal, as measured in their rate of tail wagging, differed by population in the expected directions. Low-arousal assistance dogs showed the most inhibition in a detour task when humans eagerly encouraged them, while more highly aroused pet dogs performed worst on the same task with strong encouragement. Our findings support the hypothesis that selection on temperament can have important implications for cognitive performance."
In the past researchers discussed how successful problem solving is influenced by an animals temperament. Researchers have termed this the emotional-reactivity hypothesis. This hypothesis has been used in the past to explain problem-solving skills in dogs. According to the original research paper, one largely untested prediction of the emotional-reactivity hypothesis is that the effect of temperamental differences on problem solving will be apparent even within species.
- 30 pet dogs
- Ages range from 8-months to 11-years old
Drs. Bray, Hare and MacLean chose to work with pet and assistance dogs because these are two different groups of dogs. Pet dogs are used to human gestures, yet some may receive very little professional training apart from basic obedience training. Assistance dogs on the other hand receive a lot of professional training and are very attuned to human gestures. Working dogs are required to perform acts that require inhibitory control, such as following commands while a cat walks around the training area.(Bray EE, MacLean EL, & Hare BA. July 2015.)
Past research has demonstrated that failure on tests of inhibitory control is linked to high aggression in dogs, decreased tolerance of close contact, and negative responses to novelty. (Wright HF, Mills DS, Pollux PMJ (2011) Development and validation of a psychometric tool for assessing impulsivity in the domestic dog. Int J Comp Psychol 24(2):210225.)
How The Research Was Done
In this research, Dr. Bray and colleagues asked the dogs to get a jerky treat from a person who was standing behind a transparent plastic barrier. The barrier was 6 feet wide and 3 feet tall. To succeed in this test, the dogs had to walk around the plastic barrier. They were not allowed to take a short cut to get to the person with the treat. If they did, they would bump right into the plastic barrier.
The researchers predicted there would be measurable differences between pet and assistance dog arousal levels and how they react to it. They wanted to measure the dogs' ability to exercise inhibitory control, and how each type of dog would either benefit or become impaired by being over or under-aroused. Dr. Bray kept in mind that assistance dogs have gentler temperaments as a result of selective breeding for their temperament. They also have extensive training, so they are able to prevent themselves from being distracted despite levels of arousal.
- Each dog was recorded on video.
- Each dog had their baseline temperament measured according to the number of tail wags per minute.
The service dogs were generally more cool in the face of stress or distraction, whereas pet dogs tended to be more excitable and high-strung, said Dr. Bray (Science Daily).
- Both the assistance dog and the pet dog groups were able to solve the puzzle.
- Researchers concluded that the optimal time it took for each dog to complete the test depended on each dogs temperament.
- Excitable dogs took longer to perform the task when they were subjected to more excitement and stimulation.
Charline Brown, a 2-year old Spaniel, reacted terribly during one of the high-arousal trials. He shut down, barking and running around, almost running out of time to complete the test.
"In the first 5 trials she did fine and solved the puzzle quickly with no problems," said Dr. Bray (Science Daily). "Then when the high-arousal trials started she choked. She just couldn't figure it out. Adding more excitement pushed the pet dogs over the edge and impaired their ability to perform at their peak."
The researchers believe that the results will help them to develop better tests to see which dogs are good candidates for service dog training programs.
Claudia Bensimoun is a freelance writer in West Palm Beach.