Every time you recall a memory it can be overwritten and changed
This is a fascinating study wherein scientists had some subjects watch the pilot episode of 24, describe what they saw in a scene, and then the scientists talked the subjects into altering their memories of the tv they had just seen, so that they remembered falsely.
Disturbing stuff.
When Memories are Remembered, They Can Be Rewritten – Phenomena: Not Exactly Rocket Science
Chan’s study is the latest to show how easy it is to disrupt our memories, and supplant what we think we know with misinformation. In this case, he and colleague Jessica LaPaglia from Iowa State University showed volunteers the pilot episode of 24 and then selectively rewrote some of their memories of the show’s events. For example, some of the volunteers came to believe that an assassin (Mandy!) knocked out a flight attendant with a stun gun, when she actually used a hypodermic syringe.
It wasn’t just a simple matter of saying Mandy used a stun gun. That wouldn’t have worked. Instead, Chan and LaPaglia fed their volunteers with false information immediately after they had actively remembered what they had seen. Then, and only then, did the new memories overwrite their old ones.
The trick relies on a quirk of memory that has come to light in recent years. I’ve written about it before:
Every time we bring back an old memory, we run the risk of changing it. It’s more like opening a document on a computer – the old information enters a surprisingly vulnerable state when it can be edited, overwritten, or even deleted. It takes a while for the memory to become strengthened anew, through a process called reconsolidation. Memories aren’t just written once, but every time we remember them.
This means, somewhat ironically, that the remembering something creates a critical window in which memories can be erased or manipulated. Many scientists have done this in rodents and humans using drugs or conflicting information. But these experiments usually manipulate single simple memories, such as a drug craving or a fearful association between a colour and an electric shock.