How Brains Forget Memories Through Two Distinct Mechanisms

If you've been having trouble with the "forget" part of "forgive and forget," you're in luck: a new discovery reveals two ways that our minds can erase memories.

According to the study, conducted by researchers at the University of Cambridge, the brain erases traumatic and otherwise undesirable memories via two opposite mechanisms. The findings are published in the October 17 copy of Neuron.

In one method researchers have termed "direct suppression," the brain inhibits the processing of the hippocampus, a region of the brain critical for the formation of conscious memories. This interference prevents the memory from ever being recorded in the first place.

The other method, called "thought substitution," doesn't halt the memory from being recorded; instead, the brain alters its own wiring to replace the memory with something else.

"This study is the first demonstration of two distinct mechanisms that cause such forgetting: one by shutting down the remembering system, and the other by facilitating the remembering system to occupy awareness with a substitute memory," said Roland Benoit, the study's lead author, in a press release.

Researchers conducted the study with 36 volunteers instructed to remember and forget specific pairings of words. According to Business Insider, half the individuals were instructed to replace one word with a different word, while the other half were instructed to forget the word entirely. Researchers watched participants' brain activity while they repeatedly committed words to memory, then attempted to forget them.

The findings could have implications for a whole host of populations including veterans suffering from PTSD, or victims of traumatic crime. Others, seeking only to forget their embarrassing actions at the holiday office party, may eventually benefit as well.