Episodic Memory: A Human-Only Trait?
I vividly recall that cold December day I drove from Virginia to North Carolina to meet a one-year-old Great Dane I was interested in adopting. As soon as I got out of the car I saw her coming, dragging her foster mom behind her then jumping on me with giddy excitement. I remember the tiny condo in which she lived, her “roomie,” a super-sized older Dane with too many ailments to recount, and finally loading her into the back of my SUV, surprised that she fell asleep within minutes─also terrified I would fail her.
What does all that have to do with a dog’s memory? Everything.
What I remembered that day is an example of episodic memory, something until recently thought to be an exclusively human trait. It’s defined by Wikipedia as “the memory of autobiographical events (times, places, associated emotions, and other contextual who, what, when, where, why knowledge) that can be explicitly stated or conjured.”
An important hallmark of episodic memories is that they are saved without any knowledge that they may have to be recalled in future.
We use episodic memory to recall past events at will and think about future ones. This capability shapes our concept of time.
The question is, would my adopted Great Dane Thea remember our meeting the way I did?
Most scientists would say no. The kind of episodic memory I used to arbitrarily conjure up all the related things that day─from the weather and condo, to Thea’s expression and what I felt─would not be possible for a dog.
Study Shows Episodic-Like Memory in Dogs
But a study whose results were published in the December 2016 issue of Current Biology reveals that perhaps dogs do have some form of episodic memory. A team of researchers in Budapest, Hungary used a “Do as I Do” test, which resulted in findings that showed evidence of episodic-like memory in dogs.
While more research must be done to further decode memory in dogs, these findings cast new light on what we thought were clear differences between us and them.
Other Ways Dogs Remember
Even without this fascinating study, dogs have remarkable abilities that, to us, look a lot like human memory.
For instance, dogs have natural rhythms associated with their internal circadian clock, which is modified by light and temperature. So your dog doesn’t necessarily “remember” that he typically gets dinner at 6 p.m. every night. But this rhythm is helping cue him at that particular time of day that it’s time for dinner and, voila! There he is, in front of his bowl salivating at 5:59 p.m.
Dogs also have associative memory. This is when your dog associates a sound, smell or visual cue with a known behavior or emotion. An example of this is when you grab your dog’s leash and he charges for the door anticipating a walk.
Dogs can also recall information related to locations or arrangements, something called spatial memory. My Great Dane practically pees her pants when we’re within blocks of her doggy daycare. Sound familiar?
Long and Short-Term Memory
A discussion on this topic would be remiss without touching on the difference between short-term and long-term memory in dogs. Most studies suggest that a dog’s short-term memory lasts up to about two minutes. So if your dog has an accident in the house and you find it 15 minutes later, don’t bother scolding him. While this may seem like horrible short-term memory, consider that the average memory duration for all animals is 27 seconds, with chimps’ memory as short as 20 seconds, according to a study reported on by National Geographic.
Dogs also have long-term memory. Dogs tap into this for associative and spatial memory. According to Monique Udell, assistant professor of animal and rangeland sciences at Oregon State University, this type of memory manifests differently in dogs and humans: “Dogs can hold things in memory for a long time,” she said. “But what they remember and how long they can remember it for has a lot to do with context.” (Taken from an excerpt in “How Much do Cats and Dogs Remember,” Live Science, April 8, 2017.)
Memory and the Dog-Human Bond
This context, while mostly influenced by survival needs and particularly food, has also been shown to manifest in dog-human bonds. This is brought to life by videos you may have seen showing military personnel being greeted by their dogs after years away. The reaction by dogs is stunning. I’ve yet to watch one with a dry eye.
So, while the jury is still out on just how complex a dog’s memory is, one thing is for sure. Whatever our differences, our bond with dogs is not diminished. But I probably didn’t need to tell you that, did I?