When it comes to laws of physics Fido is on the ball

‘They viewed “wrong” scenarios with enlarged pupils, suggesting the logic was contrary to expectation’

DOGS notice when objects violate Newton’s laws of physics, scientists have found.

The study by the University of Veterinary Medicine, Vienna, found that dogs stared for longer and their pupils widened when 3D animated balls started rolling on their own rather than being set in motion by colliding with another ball.

Newton’s first law of motion states that an object at rest will remain at rest unless a force acts on it.

The reaction of the animals suggested that they were surprised when the virtual balls moved in a way they didn’t expect them to, the study’s lead researcher said.

Christoph Völter said this response signified the “starting point for learning” and that human infants six months or older and chimpanzees also stared longer during these kinds of “violation of expectation” tests concerning their physical environment.

“You have expectations about the environment – regularities in your environment that are connected to physics – and then something happens that doesn’t fit. And now you pay attention,” he added.

Mr Völter and his colleague Ludwig

Huber, also at the University of Veterinary Medicine, trained 14 adult dogs – mainly border collies and labradors – to place their heads on a chinrest in front of eye-tracking equipment and a computer screen.

They showed the animals brief videos, in random order, of colourful 3D balls in motion – one with a contact condition that one ball set another in motion, and the other with a no-contact condition.

For example, in one of the test videos, a ball rolls towards a second stationary ball and then runs into it, thereby causing the second ball to start moving just as Newton’s first law of motion describes. In another video, however, the first ball rolls towards the second ball but stops suddenly before reaching it. Despite not being hit by the first ball, the second starts rolling away by itself, which is contrary to basic principles in physics.

Like humans and chimpanzees, the dogs were found to fix their eyes longer on the balls that didn’t follow basic laws of contact physics, Mr Völter said. What he found even more convincing, however, was that they consistently viewed the “wrong” scenarios with more enlarged pupils, which suggested that the logic was contrary to their expectations.

Similar studies in humans have shown that pupils dilate more in response to increased mental efforts such as calculations or stronger emotions, which is known as the psychosensory pupil response.

Previous research into dogs has also hinted that their pupils dilate more when looking at angry human faces in comparison to happy faces.

Although the study does not mean that pet dogs understand physics, Mr Völter said that it suggested the dogs have an implicit and “intuitive” understanding of their physical surroundings.

He concluded: “This is a sort of [an] intuitive understanding expectation.

“But that’s also the case for humans, right? The infant at seven months of age has expectations about the environment and detects if these expectations are violated.

“I think they build up on these expectations, and build a richer understanding of their environment based on these expectations.”