Study Finds Pets Can Tell Time, May Be Using It to Judge You
The findings of the study could help with the early detection of Alzheimer's disease in humans
Yes, your cat does know his feeding schedule and your dog knows when she is usually walked — or at least our pets have an idea of how time works, says a new study from Northwestern University.
According to a statement from the school, a recent study uncovered a set of neurons in the medial entorhinal cortex of a mouse’s brain “that turn on like a clock when an animal is waiting.”
“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,” said Daniel Dombeck, the associate professor of neurobiology at Northwestern’s Weinberg College of Arts and Sciences, who led the study. “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.”
In this groundbreaking study — recently published in the journal Nature Neuroscience — Dombeck and his team studied the medial entorhinal cortex of mice. The team chose this part of the brain, which is located in temporal lobe, because it is the area connected to memory and navigation. Dombeck hypothesized it might also be the area responsible for an animal’s “encoding of time.”
To test this theory, researchers created a virtual test for their mice subjects called the “door stop task.” For this experiment a mouse would run on a physical treadmill through a virtual environment made up of a hallway leading to a door. By running the environment, the mouse learned that if he followed the hallway halfway down to a door, the door would open after six seconds, and then he’d receive a reward.
Once the mouse learned where the door was, the door was replaced with an invisible door. Even when the mice in the study could not see the door, they still knew to stop at the invisible door’s location and wait six seconds before continuing through the invisible door to get their reward.
“The important point here is that the mouse doesn’t know when the door is open or closed because it’s invisible,” James Heys, one of the study’s authors, said in a statement. “The only way he can solve this task efficiently is by using his brain’s internal sense of time.”
The previously unknown set of neurons responsible for this understanding of time were discovered by imaging the brains of the participating mice while they completed the door stop task.
“As the animals run along the track and get to the invisible door, we see the cells firing that control spatial encoding,” Dombeck said. “Then, when the animal stops at the door, we see those cells turned off and a new set of cells turn on. This was a big surprise and a new discovery.”
This discovery of “timing cells” means your cat is likely aware when you are 10 minutes late with his breakfast, but it could also be a breakthrough for humans as well. Since the entorhinal cortex is often one of the first parts of the brain affected by the onset of Alzheimer’s disease, this same “door stop task” could be replicated for humans to help with the early detection of Alzheimer’s.