Do Dogs Think About the Past?

People have a remarkable ability to remember and recall events from the past, even when those events didn’t hold any particular importance at the time they occurred. Recognizing what we ate yesterday for breakfast or remembering who we talked to the week before is something that comes naturally to us humans; it’s called episodic memory. But pet parents often wonder, do dogs think about the past like I do?

Researchers in 2016 investigated this idea with a study on the topic of canine memory. In the journal Current Biology, the group published a report showing that dogs have that kind of “episodic memory” too.

The study found that dogs can recall a person’s complex actions even when they don’t expect to have their memory tested. “The results of our study can be considered as a further step to break down artificially erected barriers between non-human animals and humans,” says Claudia Fugazza of MTA-ELTE Comparative Ethology Research Group in Budapest, Hungary. “Dogs are among the few species that people consider ‘clever,’ and yet we are still surprised whenever a study reveals that dogs and their owners may share some mental abilities despite our distant evolutionary relationship.”

Evidence that non-human animals use episodic-like memory has been hard to come by because you can’t just ask a dog what it remembers. 

In 2015, Marc Bekoff, an evolutionary biologist from the University of Colorado, reflected on the subject of canine memory when he saw an essay called “Dogs Don’t Remember,” published by Dr. Ira Hyman. He disagreed, saying, “So, all in all, unless others and I are missing something, dogs do remember yesterday…There are many examples of dogs and other animals “remembering yesterday.” Think of dogs and other animals who have been severely abused. Think of dogs who remember where they and others peed and pooped, dogs who remember where their friends and foes live, dogs who change their behavior based on what they learned, and dogs who remember where they’re fed and where they’ve cached food and other objects. The list goes on and on.”

In the study led by Fugazza, the researchers took advantage of a training method called “Do as I Do.” Dogs trained to “Do as I Do” can watch a person complete an action and then do the action themselves. For example, if their owner jumps in the air and then gives the “Do it!” command, the dog would jump in the air too.

The fact that dogs can be trained in this way alone wasn’t enough to prove episodic memory. That’s because it needed to be shown that dogs remember what they just saw a person do even when they weren’t expecting to be asked or rewarded. 

The researchers first trained 17 dogs to imitate human actions with the “Do as I Do” training method to get around this problem. Next, they did another round of training in which the researchers trained dogs to lie down after watching the human action, no matter what it was.

After the dogs had learned to lie down reliably, the researchers surprised them by saying, “Do It,” and the dogs did. In other words, the dogs recalled what they’d seen the person do even though they had no particular reason to think they’d need to remember. They showed episodic-like memory.

Dogs were tested in that way after one minute and after one hour. The results show they were able to recall the demonstrated actions after both short and long time intervals. However, their memory faded somewhat over time.

The researchers say that the same approach can most likely be used and adapted in a wide range of animal species to understand better how animals’ minds process their actions and that of others around them.

“From a broad evolutionary perspective, this implies that episodic-like memory is not unique and did not evolve only in primates but is a more widespread skill in the animal kingdom,” Fugazza says. “We suggest that dogs may provide a good model to study the complexity of episodic-like memory in a natural setting, especially because this species has the evolutionary and developmental advantage to live in human social groups.”

For all those dog owners out there: your dogs are paying attention and they’ll remember.