People know that dogs have a strong sense of smell. Now, Irish scientists have done an experiment showing that dogs can distinguish the smell of a person when they are relaxed and stressed.
If you ever think dogs seem to know when people feel stressed, you are right. Irish scientists conducted an experiment showing that dogs can distinguish the smell of people when they are relaxed and stressed.
As we all know, dogs have a strong sense of smell. Dogs have been used to track missing persons and detect drugs, bombs and even diseases.
But scientists are not sure if people under stress have a special smell. If they do, they are not sure the dog will notice the scent. As it turns out, the answer to both questions is "yes".
researchers at Queen's University of Belfast studied four dogs, led by scientist Clara Wilson. They teach dogs to use a special odor test device with three openings. Scientists use snacks and rewards to train dogs to find the right openings and signals.
Scientist teaches dogs to use odor testing devices with three openings. Use snacks to train to find the correct opening and signal.
Over time, these dogs are given increasingly unpleasant jobs. The ultimate goal is to see if they can smell stress from a person’s breathing and sweat.
All day, our bodies change and produce different chemicals. These chemicals emanate from our breathing and sweat, slightly changing the way we smell. But it is not clear whether stress leads to perceived changes.
Therefore, the researchers collected breathing and sweat samples from 36 different people. When people are calm, they get a sample, and when they are stressed, they get a sample.
The calm part is easy. They ask people to report their stress levels and measure their heart rate and blood pressure. People are asked to wipe their skin with a clean cloth. Then they had to put the sample into the test tube, breathe hard three times, and then seal the test tube.
To put pressure on people, scientists asked a very difficult mathematical problem and forced people to complete it quickly in their minds. They are not good about it. They kept telling people to hurry up and didn't help them. It lasted for three minutes.
Then the researchers collected two more sweat and breathing samples. They also asked people about their stress levels and measured their heart rate and blood pressure. Most people say they feel stressed. On average, the heart rate increased from about 91 times per minute to about 105 times per minute.
Scientists used one of the pressure samples and two clean cloths to train the dog to find the odor of stress.
These dogs have done such tests 720 times. They correctly identified the stress samples about 94% of the time.
Then there is the challenge: this dog has three choices: a sample from a calm person, a pressure sample from the same person, and a clean cloth. The dogs had a total of 720 such tests. They correctly identified the stress samples about 94% of the time.
results clearly show that the pressure does have a odor that can be perceived by the dog. Wilson Ms. Wilson said the news could be particularly useful for training service dogs and their job is to help relieve stress.
