How the Brain Keeps Time Finally Discovered by Scientists

The Big Ben clock in London, which does not explain how the brain creates a sense of time. Toby Melville/Reuters

Read this sentence out loud: "My brain knows how to keep time."

Now read it faster.

If scientists were watching your brain as you read the same line at different speeds, they might not see as much of a difference as you'd think, a new study in Nature Neuroscience shows. Neurons appear to fire in a similar pattern, whether operating at fast or slow speeds, the research found. But interestingly, the same patterns stretch or compress over time, depending on the rate of the task.

Mehrdad Jazayeri, an author on the study, told Newsweek that to do anything, from playing a melody on a piano to reading aloud a tongue twister at different speeds, the brain needs to have some sense of keeping time. Scientists used to believe that sense of time was created by something like an internal clock or central pacemaker. But, it turns out, the way the brain adjusts to allow creatures to do those actions along different scales of time doesn't look much like a clock.

They came to this conclusion by studying a group of monkeys trained to press a button at different speeds, and then by making computer models of the parts of the brain they were studying. Jazayeri's group found that neurons in parts of the brain known as the medial frontal cortex, the caudate and the thalamus produced particular patterns when the same task was performed at different speeds.

A group of neurons involved in a particular task has to go from a beginning state to an end state. As Jazayeri puts it, they have to fire in a pattern that moves them from point A to point B. That pattern doesn't change as the speed of an action changes, but the rate at which that orchestra of neurons fires to move from A to B does change.

An athlete sets his watch. Thomas Mukoya/Reuters

The researchers take this to mean that by going with these differing patterns for different tasks, the brain has a kind of dial it can turn up and down depending on the speed of the task that needs to be accomplished.

"It's as if the brain is a rubber band, and if you want to do something slower, you stretch it," Jazayeri said.

When an action, like reading a sentence, was completed at different speeds, Jazayeri's group found that these neurons always followed the same pattern, but the pattern was "stretched" over a longer interval of time and "compressed" over a shorter interval of time as needed.

So your brain does know how to keep time, but in a way that looks more like a rubber band than a clock.