Rehearsal Loop:

Daniel Levintin:

"When we have something in our minds that is important - especially a To Do item - we're afraid we'll forget it, so our brain rehearses it, tossing it around and around in circles in something that cognitive psychologists actually refer to as rehearsal loop, a network of brain regions that ties together the frontal cortex just behind your eyeballs and the hippocampus in the center of your brain. This rehearsal loop evolved in a world that had no pens and paper, no smartphones or other physical extensions of the human brain; it was all we had for tens of thousands of years and during that time, it became quite effective at remembering things."