How split memories help us perform tasks much better the second or third time around

It’s push, not pull!
It’s push, not pull!
Image: Reuters/Andrea Comas
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Now we know what’s happening in our brains when we correctly pull a door that we once (embarrassingly) pushed.

Researchers at Johns Hopkins University have concluded that we learn motor commands faster when we revisit a task because we create two separate memories—the muscle memory of how to perform the task, and the memory of the errors we made the first time around. The brain recognizes the errors it made before, and makes corrections.

Reza Shadmehr, a professor of biomedical engineering at Johns Hopkins and leader of the research team, likens our brain’s ability to critique our mistakes to that of a coach. “Learning the next similar task goes faster, because the coach knows which errors are most worthy of attention,” he said in a release about the study. “In effect, this second process leaves a memory of the errors that were experienced during the training, so the re-experience of those errors makes the learning go faster.”

Here’s how Johns Hopkins describes the experiment that the researchers conducted:

To study errors and learning, Shadmehr’s team put volunteers in front of a joystick that was under a screen. Volunteers couldn’t see the joystick, but it was represented on the screen as a blue dot. A target was represented by a red dot, and as volunteers moved the joystick toward it, the blue dot could be programmed to move slightly off-kilter from where they pointed it, creating an error. Participants then adjusted their movement to compensate for the off-kilter movement and, after a few more trials, smoothly guided the joystick to its target.

Now that they know this “coach” inside our brain exists, Shadmehr’s team wants to figure out exactly which part of the brain is responsible for it.

Meanwhile, doing the same thing over and over again and expecting a different result might not be so insane after all.