In the past few decades, dogs have moved from the backyard to the bedroom as more and more Americans consider them to be an integral part of the family. This new perception has led to an increase in awareness and research related to canine intelligence, including their ability to recall events and capacity to store memories. Research has shown that, while dogs do have some form of short- and long-term memory, it differs from that of humans.
Dogs are famous for their ability to live in the moment, and their capacity to remember concrete events is widely believed to be capped at approximately 10 to 20 seconds. As a result, when training dogs it is important to give them immediate positive or negative feedback on their actions. If your dog ripped open your garbage while you were at work, scolding him when you come home three hours later is largely ineffective because he is unable to recall what he did wrong.
Most researchers agree that dogs do not possess episodic memory, or the ability to recall past events. Our ability to train dogs, however, indicates that they are capable of remembering and acting upon a variety of language and hand signals. Additionally, there are many reported instances where dogs who have been separated from their owners for five or more years greet them as though they have never been apart. It is not yet fully understood whether this represents the capacity for true long-term memory in the way that humans comprehend it. Instead, it is believed that dogs use a combination of their senses, as well as their basic instinct for survival, to remember positive and negative circumstances. If a dog's owner has been away on military duty for two years and returns to a joyous greeting, it is likely that the dog is recalling the scent, sound and appearance of his owner, along with the association that his owner provided him with food, safety and love.
Perception of Time
Dogs' perception of the passage of time is very different from humans'. While research on this subject is limited, it is believed that dogs perceive time via their biological rhythms versus the counting of hours. For example, your dog may not realize that it has been eight hours since he last ate, but based on a combination of hormones, brain activity and body temperature he knows that it is time for dinner.
There are simple tests you can do at home to determine your dog's recall ability. To test his short-term memory, command him to sit in the center of an average-sized room. Hold up a piece of food and allow him to watch as you hide it somewhere in the room. Lead him out of the room for approximately 15 seconds, and then return. Take off the leash, and time how long it takes him to find the treat. To test his long-term memory, hide a new piece of food, lead him out of the room for five minutes, and time how long it takes him to find it. The quicker he finds the treat, the better his memory.