According to the study, your pets may be able to tell how late you are getting home. (MARTIN DEJA/GETTY IMAGES)
YOUR DOG OR CAT MAY BE able to tell if you're home late from work or if dinner is delayed.
A new study from Northwestern University revealed that animals can judge time. The study, published Monday in the journal Nature Neuroscience, is "one of the most convincing experiments" to show that animals understand time.
"Does your dog know that it took you twice as long to get its food as it took yesterday? There wasn't a good answer for that before," study co-author Daniel Dombeck said in a press release. "This is one of the most convincing experiments to show that animals really do have an explicit representation of time in their brains when they are challenged to measure a time interval."
Researchers focused on the area of the brain associated with memory, navigation and the perception of time, the medial entorhinal cortex, which is located in the temporal lobe. This part of the brain "is known to contain spatial encoding neurons that likely contribute to encoding spatial aspects of episodic memories," according to the study.
Although every memory is different, study co-author James Heys said in the release, there are always "two central features to all episodic memories: space and time." Episodic memories occur in a certain place and they are always structured in time.
To test if your dog or cat can really tell if you were out too late, the researchers conducted an experiment called the virtual door stop. During the test, a mouse ran on a physical treadmill in a virtual reality environment. The mouse then learned ro run down a hallway to a door, and after six seconds, the door opened and the mouse continued on to collect its reward.
After several sessions like this, researchers made the door invisible in the virtual reality environment. The mouse still ran to where the door used to appear and still waited six seconds before running down the track to receive its reward.
"The important point here is that the mouse doesn't know when the door is open or closed because it's invisible," Heys said. "The only way he can solve this task efficiently is by using his brain's internal sense of time."
After conducting the door tests, the researchers took images of the mice's brains to analyze the activity and discovered that neurons that control spatial encoding were firing while the mice were running to the invisible door. Those cells stopped firing when the animal arrived at the door and different cells began firing instead.
According to the study, the cells that are active during rest are actually encoding how much time the mouse has been resting.
So, if you come home to an impatient pet, it's because they can tell just how long you've been gone.