The physiological processes associated with an acute psychological stress response produce changes in human breath and sweat that dogs can detect with an accuracy of 93.75%, according to a new study (PLOS ONE).
The researchers from Queen’s Belfast University collected samples of breath and sweat from non-smokers, who had not recently eaten or drank. Samples were collected both before and after a fast-paced arithmetic task, along with self-reported stress levels and objective physiological measures: heart rate (HR) and blood pressure (BP).
Samples from 36 participants, who reported an increase in stress, HR and BP during the task, were shown to trained dogs within three hours of being collected. As per the release, at testing, dogs were asked to find the participant’s stress sample while the same person’s relaxed sample was also in the sample line-up.
Overall, dogs could detect and perform their alert behaviour on the sample taken during stress in 675 out of 720 trials, or 93.75% of the time.