Many of us may be most familiar with infrared thermography from its least valuable (I’d argue) use — ghost hunting.
It serves many far more sophisticated purposes, though, than providing fodder for those shaky-camera paranormal TV shows — from assessing medical conditions to military reconnaissance, from finding missing children to sensing mood changes in humans.
And, no big surprise, dogs.
In the latest post on Dog Spies, her blog on Scientific American, Julie Hecht recounted a recent study at the Animal Behavior, Cognition and Welfare Research Group at the University of Lincoln in the UK.
Researchers found, through infrared thermography, that the ear temperature of dogs decreased (turning blue on the camera) when they were isolated, and warmed backed up (turning red) when they reunited with people.
It’s similar to findings in studies of human stress levels — except in humans it’s the nose, instead of the ears, that is the most common giveaway.
As Hecht explained, infrared thermography picks up changes in surface temperature. When frightened, stressed or placed in unfamiliar surroundings, blood rushes away from your extremities, in dogs and humans. They get cooler as your core gets warmer and ready to react to whatever threat may be ahead.
The tip of a scared person’s nose gets cooler in such situations, just as rat paws and tails have been shown to do in experiments. In rabbits and sheep, the ears are the most obvious indicator.
Stefanie Riemer and colleagues placed dogs for brief periods in an isolated and novel environment. As the researchers expected, thermographic images of the dogs in isolation showed their ear temperature increasing, then rising when they were reunited with people.
The study appears in the current issue of Physiology & Behavior.
Six dogs were included in the study, and several were found to be unsuitable for study because their fur was too dense to get a good reading.
It seems like a technology that could be put to good use when it comes to studying dogs, and in learning more about those with behavioral issues and what triggers them.
That seems to me a better pursuit than chasing ghosts who aren’t really bothering anybody. Non-invasive, physically, as it is, even infrared photography has the potential for being cruel.
In a study in Italy two years ago, 20 bank tellers who had been robbed at gunpoint were shown a series of faces — happy, neutral, angry, etc. On the fifth face, the researchers exposed them to a loud and unexpected blast, and recorded, thermographically, how the blood left the noses and face.
Half of the tellers had already been diagnosed with PTSD.
Whether the researchers ended up giving PTSD to the other half is not addressed in the study.
(Photo: S. Riemer / Physiology & Behavior)