Dogs remember events like humans do, study suggests

Dogs have ‘episodic memory’ similar to humans, a new study suggests. (Mitch Cochran / CTV News)

Researchers in Hungary have found evidence that dogs’ memories work more like humans’ than previously thought.

It was already obvious that our furry friends can “remember” that they’ll be rewarded with treats if they’ve been conditioned to follow commands.

But what wasn’t known, before this new study published in Current Biology, is that dogs record specific episodes of life that have no particular meaning to them at the time, and are able to replay those episodes in their heads later on.

This is known as “episodic memory” and it’s particularly interesting because it’s a requirement for human-style self-awareness. This is the type of memory that allows us to replay events from our lives when asked about them later, such as who was at a party last week or what it was like for us on September, 11, 2001.

Before this study, researchers had only shown episodic memory in chimpanzees, which are a close relative of humans.

To test for episodic memory, the researchers had 17 dogs trained at home to copy whatever action their owners did as soon as they heard the voice command “do it.” There were six actions in total, using three objects (a bucket, an umbrella and a chair).

For example, if the owner touched the open umbrella with one hand and then shouted “do it,” the dog -- once trained -- would touch the umbrella with one paw in order to receive a treat or toy. Or if the owner walked around a bucket, the dog would walk around a bucket as soon as he or she heard “do it.”

Once the dogs had mastered the “do it” command, the dogs were re-trained to lie down on a blue carpet upon receiving a “lie down” command. They were no longer required to record in their heads which of the actions the humans had just performed in order to get a treat.

But they remembered the scenes of the humans performing the actions anyway.

The researchers proved this by showing the dogs one of the actions and then taking the dog behind a screen, where they could no longer see the objects.

After a minute behind the screen, the owners brought the dogs back out to where they could see the objects again. In all but one case, the dogs immediately lay down on the carpet, showing they were still expecting to receive the lie down command and get a treat.

But this time around, the dogs were surprised with the “do it” command. They had no reason to expect a minute earlier that they would need to remember which of the actions had been performed, but now they needed that memory to get their treat. Most of the dogs remembered the episode showing which action the human had performed, replayed it in their head and performed it, too. See a video of that here.

The same process was repeated a second time with the dogs away from the objects for a full hour, instead of a minute. A smaller but still significant number of the dogs still remembered the action an hour later when surprised with the “do it” command.

In other words, dog memories are a lot more sophisticated than we thought.