(Press-News.org) DURHAM, N.C. -- People aren't the only ones who perform better on tests or athletic events when they are just a little bit nervous -- dogs do too. But in dogs as in people, the right amount of stress depends on disposition.
A new study by researchers at Duke University finds that a little extra stress and stimulation
makes hyper dogs crack under pressure but gives mellow dogs an edge.
The findings appear online in the journal Animal Cognition.
According to an idea in psychology called the Yerkes-Dodson law, a little stress can be a good thing, but only up to a point.
A task that isn't demanding or challenging enough can make it hard to stay engaged and perform at one's peak. But when the pressure becomes too much to handle, performance is likely to suffer again.
The idea is the relationship between stress and performance follows a Goldilocks model: Both people and animals function best when the level of stress is not too much, nor too little, but just right.
"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 study co-author Emily Bray, who was an undergraduate at Duke at the time of the study. "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."
Researchers first observed this pattern more than a hundred years ago in lab rats, but it has since been demonstrated in chickens, cats and humans. In a new study, a Duke team consisting of Bray and evolutionary anthropologists Evan MacLean and Brian Hare of Duke's Canine Cognition Center wanted to find out if the conditions that enable certain animals to do their best also depend on the animal's underlying temperament.
In a series of experiments, the researchers challenged dogs to retrieve a meat jerky treat from a person standing behind a clear plastic barrier that was six feet wide and three feet tall. To get it right, the dogs had to resist the impulse to try to take the shortest path to reach the treat -- which would only cause them to whack into the barrier and bump their heads against the plastic -- and instead walk around the barrier to one of the open sides.
In one set of trials, an experimenter stood behind the barrier holding a treat and called the dog's name in a calm, flat voice. In another set of trials, the experimenter enthusiastically waved the treat in the air and used an urgent, excited voice. (See YouTube video at https://youtu.be/j6bfo5IlCEY)
The researchers tested 30 pet dogs, ranging in age from an eight-month-old Jack Russell terrier named Enzo to an 11-year-old Vizsla named Sienna. They also tested 76 assistance dogs at Canine Companions for Independence in Santa Rosa, California, a non-profit organization that breeds and trains assistance dogs for people with disabilities.
The researchers studied video recordings of each dog and estimated their baseline temperament in terms of tail wags per minute. "The service dogs were generally more cool in the face of stress or distraction, whereas the pet dogs tended to be more excitable and high-strung," Bray said.
Both groups of dogs were able to solve the puzzle. But the optimal amount of stress and stimulation depended on each dog's disposition.
For the dogs that were naturally calm and laid-back -- measured by how quickly they tended to wag their tails -- increasing the level of excitement and urgency boosted their ability to stay on task and get the treat.
But for excitable dogs the pattern was reversed. Increasing the level of stimulation only made them take longer.
In one high-arousal trial, a two-year-old spaniel named Charlie Brown lost it and shut down, barking and zipping around crazily until she almost ran out of time.
"In the first five trials she did fine and solved the puzzle quickly with no problems," Bray said. "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," Bray said.
The results will help researchers develop better tests to determine which dogs are likely to graduate from service dog training programs, for example.
INFORMATION:
This study was funded by the AKC Canine Health Foundation, the National Science Foundation (DGE-1321851), the Office of Naval Research (NOOO14-12-1-0095) and the National Institute of Health (5 R03 HD070649-02).
CITATION: "Increasing Arousal Enhances Inhibitory Control in Calm But Not Excitable Dogs," Emily Bray, Evan MacLean and Brian Hare. Animal Cognition, July 2015.
DOI: 10.1007/s10071-015-0901-1
A class of drugs used to treat diabetes may be associated with protection against Parkinson's disease (PD), according to research published this week in PLOS Medicine. The study, conducted by Dr. Ruth Brauer, of the London School of Hygiene & Tropical Medicine, found a lower incidence of PD among people using a glitazone drug (either rosiglitazone or pioglitazone) to treat diabetes when compared to people who had used different treatments for diabetes.
The cohort study was conducted using data from the UK Clinical Practice Research Datalink, and compared individuals with ...
A type of drug used to treat diabetes may reduce the risk of developing Parkinson's disease, according to a new study published in PLOS Medicine.
The research, led by the London School of Hygiene & Tropical Medicine, found that diabetes patients taking glitazone antidiabetes drugs (either rosiglitazone or pioglitazone) had a 28% lower incidence of Parkinson's disease than people taking other treatments for diabetes who had never taken glitazones. [1]
Glitazones are a class of drug that activate the peroxisome proliferation-activated gamma (PPARγ) receptor, which ...
VANCOUVER, B.C. and DURHAM, N.C. - A Phase III, individually randomized trial has found conditional cash transfers for school attendance did not reduce the risk of HIV among high-school aged women in South Africa, investigators from the HIV Prevention Trials Network (HPTN) reported today at the 8th International AIDS Society (IAS) Conference on HIV Pathogenesis, Treatment and Prevention in Vancouver, Canada.
The new finding is from HPTN 068, the first individually randomized study of young women conditioned on school attendance with an HIV incidence endpoint. In the trial, ...
An international panel of leading scientists is launching a new TripAdvisor-style website aimed at helping researchers choose better-quality research tools - and avoiding potentially serious errors in biomedical research.
In a 'call to action' published today (Tuesday), the international expert panel warns that many scientists are unwittingly using poor-quality chemical probes, leading to mistaken conclusions being drawn from research studies.
The expert panel - made up of researchers from non-profit research institutions and from biotechnology and pharmaceutical companies ...
July 2, 2015 - Porcine reproductive and respiratory syndrome virus (PRRSV) is the most widespread disease in the swine industry. In sows, PRRSV causes reproductive problems during gestation, including abnormal litters or abortions. Growing pigs with the disease will have respiratory problems and poor growth.
In 2012, Holtkamp and colleagues estimated the annual losses due to PRRSV to be a staggering $664 million in the U.S. alone. Producers on larger farms use vaccines and enhanced biosecurity measures to prevent eradicating an entire herd during a PRRSV outbreak. Unfortunately, ...
NEW YORK, July 21, 2015 -- A recent study conducted at Nathan S. Kline Institute for Psychiatric Research (NKI) and NYU Langone Medical Center implicates a new culprit in Alzheimer's disease development. The research reveals that ßCTF -- the precursor of the amyloid beta (Aß) peptide -- acts at the earliest stage of Alzheimer's to initiate a range of abnormalities leading to the loss of groups of neurons critical for memory formation. Results from the study are published online July 21, 2015 in the journal, Molecular Psychiatry, and the article has been selected ...
WASHINGTON -- In animal models, acupuncture appears to impact the same biologic pathways ramped up by pain and stress, analogous to what drugs do in humans. Georgetown University Medical Center (GUMC) researchers say their animal study, published online in Endocrinology, provides the strongest evidence to date on the mechanism of this ancient Chinese therapy in chronic stress.
"The benefits of acupuncture are well known by those who use it, but such proof is anecdotal. This research, the culmination of a number of studies, demonstrates how acupuncture might work in the ...
Electroconvulsive therapy remains one of the most effective treatments for severe depression, but new UNSW research shows ultra-brief pulse stimulation is almost as effective as standard ECT, with far fewer cognitive side effects.
The study, published today in the Journal of Clinical Psychiatry, is the first systematic review to examine the effectiveness and cognitive effects of standard ECT treatment, brief pulse stimulation, versus the newer treatment, known as ultra-brief pulse right unilateral (RUL) ECT.
It comes after previous trials had shown conflicting results. ...
Native Americans living in the Amazon bear an unexpected genetic connection to indigenous people in Australasia, suggesting a previously unknown wave of migration to the Americas thousands of years ago, a new study has found.
"It's incredibly surprising," said David Reich, Harvard Medical School professor of genetics and senior author of the study. "There's a strong working model in archaeology and genetics, of which I have been a proponent, that most Native Americans today extend from a single pulse of expansion south of the ice sheets--and that's wrong. We missed something ...
There is archaeological evidence of modern humans in the Americas by ca. 15 thousand years ago (KYA). However, there is still debate over exactly when and how many times the ancestors of present-day Native Americans entered the New World from Siberia. A large genome-scale study conducted by an international team headed by the Centre for GeoGenetics at the University of Copenhagen has now provided answers to these questions. The study reveals that the ancestors of all present-day Native Americans arrived in the Americas as part of a single migration wave, no earlier than ...
