Chimpanzee heart check via digital camera

A world-first experiment to measure chimpanzee heart rates via a digital camera could help curb heart problems in great apes in captivity and supply priceless insights into how their brain develops from an early age.

Using a contact-free technique to extract cardiac signals from chimpanzees by filming subtle movements of their face or thorax, and monitoring their emotional response to different stimuli, a team of researchers led by the University of South Australia (UniSA) has made some startling discoveries.

Chimpanzees – our closest living relatives – show similar responses to human babies after they experience fear, excitement, or joy, causing their heart rate to extend or decrease.

Their response to videos of nature scenes can also be the identical as humans, relaxing them and lowering their heart rate significantly, despite not being aware of the environment.

By monitoring their heart rates from a distance, researchers are confident they’ll pinpoint early signs of cardiac disease in chimpanzees – certainly one of the important causes of mortality in captive great apes – and flag these endangered animals for treatment.

Seven chimpanzees were filmed in captivity from a brief distance on the Wolfgang Koehler Primate Research Centre in Leipzig, Germany, for the study. UniSA engineers were sent the footage and used artificial intelligence to find out the guts rates.

Distant sensing engineer UniSA Professor Javaan Chahl says it’s the primary time that chimpanzee heart rates have been recorded by a digital camera, extracting cardiac signals from their facial hues using image-processing algorithms.

Previous studies have either relied on sensors attached to the chimpanzee’s body, requiring primates in captivity to be trained to tolerate them, or ensuring the animal is anaesthetized before undertaking basic health checks.

The researchers not only recorded chimpanzee heart rates using the brand new technology, but in addition compared how the apes’ heart rates modified when shown videos of aggressive behaviour between chimpanzees from different groups, scenes of chimpanzees eating, and nature videos.

Lead writer, UniSA PhD student Danyi Wang, says the apes’ heart rate increased when viewing video footage of chimps fighting and feeding, and slowed when taking a look at nature scenes.

“Heart rate changes might be linked to emotional responses, mental effort, attention and focus,” Danyi says. “Babies show emotional responses early in development, which might be observed by physiological changes that help them adapt and integrate into their environment. We observed the identical within the chimpanzees we monitored.

“Their responses to viewing nature scenes could possibly be an innate physiological response to the natural world. We all know that when humans spend time in nature, or view nature-related stimuli, it has a chilled effect. It appears nature has the identical effect on chimpanzees, and this could possibly be deeply rooted in our evolutionary history.”

Because primates have similar DNA to humans, monitoring their physiological changes may provide vital information concerning the development of their considering, attention, language, learning, memory and perception.

Prof Chahl says, as with human infants, heart rate measures could possibly be used to check recognition memory and subsequently help reveal mental processes in numerous contexts.

“This might not only complement existing efforts to grasp the evolution of cognition, nevertheless it would also enable us to check populations that otherwise don’t engage in cognitive tasks, comparable to very young or untrained primates.”

Heart problems could be very common in captive great apes, typically because of age-related changes, thickening of the guts muscles and reduced elasticity. By monitoring their heart, researchers imagine they are going to give you the option to detect abnormal heart rhythms and potential signs of cardiac disease earlier.

Our contact-free technique opens up recent routes to check primates’ emotional and cognitive states and can also greatly enhance the health management of a wide selection of animal species.”

Professor Javaan Chahl, Distant Sensing Engineer, UniSA

The study is published in Behaviour Research Methods, certainly one of the world’s leading journals in experimental psychology.