A 2015 study in the Journal of Neuroscience shows that rehearsing newly-learned information stimulates a brain region known as the posterior cingulate. This area is activated when you lay down a memory and rehearse that information, and it is essential to creating permanent memories. The posterior cingulate is also highly vulnerable to damage associated with Alzheimer’s disease.
In the study, researchers used functional magnetic resonance imaging (fMRI) scans to observe the brains of a group of participants as they watched 26 brief narrative videos on a variety of subjects, such as a YouTube video of neighbors playing practical jokes on one another. Participants were given a 40-second period after viewing each of 20 videos to mentally review or discuss the clips out loud; no time was allowed for this type of rehearsal following six of the videos.
The fMRI scans showed that both viewing and rehearsing the video clips involved activity in the posterior cingulate: The more brain activity observed, the more likely a participant was to accurately recall the video a week later. For as long as two weeks after viewing the videos, participants were able to recall details of the 20 videos they had rehearsed, but largely unable to recall the non-rehearsed videos.
“We know that recent memories are susceptible to being lost until a period of consolidation has elapsed,” said the lead researcher of the study. He said his findings suggest that a brief period of rehearsal has a huge effect on the ability to remember complex information.