The findings, reported in the Journal of Neuroscience, have implications for any situation in which accurate recall of an event is critical, such as witnessing an accident or crime.
“In this study we have shown that a brief period of rehearsal has a huge effect on our ability to remember complex, lifelike events over periods of one-two weeks,” said lead researcher Chris Bird from University of Sussex in Britain.
The study showed that the brain region known as the posterior cingulate — an area whose damage is often seen in those with Alzheimer’s — plays a crucial role in creating permanent memories.
This region not only helps us to recall the episodic details of an event but also integrates the memory into our knowledge and understanding, which makes it resistant to forgetting.
The study involved showing participants 26 short videos of clips taken from YouTube of around 40 seconds in length with a narrative element.
For example, one called ‘nasty neighbours’ depicted two men playing practical jokes on each other.
For 20 of the videos, the participants were given around 40 seconds after each video to relate either in their heads or speak out loud details of the video.
For the remaining six videos, this rehearsal period was not given.
Up to two weeks later, participants were still able to recall many details of the videos they had rehearsed, whereas the non-rehearsed videos were largely forgotten.