We are desperate to fight forgetting — it scares us, it annoys us and it can cost us.
Yet there are also memories we want to forget.
- And day to day, we're able to learn, make decisions and move through life because the brain balances forgetting irrelevant information and experiences, with remembering important ones, Alison writes.
What's happening: Rather than being a flip side or failure of memory, forgetting is being studied as a brain process in its own right.
- Psychologists have studied forgetting for decades, including how we control our memory by substituting thoughts or by directing some attention, but not too much, to an unwanted memory.
Now, neuroscientists are starting to figure out how the brain forgets.
- Neurons represent memories as patterns of firing between themselves in the short term. In the long term, they're etched in connections between neurons that strengthen with repeated firing.
- Like remembering, there may be different ways the brain forgets — memories can fade over time if connections between neurons weaken, or similar memories may interfere with one another.
A flurry of recent papers and media suggests the brain also actively forgets — when retrieving memories or learning new information.
- It could even be the default state of the brain, proposes Ronald Davis, a Scripps Research Institute neurobiologist who studies forgetting in fruit flies.
- Soon after a new memory is formed, he says, the neurotransmitter dopamine acts as a "forget" trigger in a cascade of chemical changes known to affect the connections between neurons. Memories deemed important are stabilized, others aren't.
What's next: As Alzheimer's disease drug trials fail and projected costs of dementia rise, researchers want to home in on new molecules to target for treatments, but Davis cautions it is early days for aspirations of altering forgetting with drugs.
Meanwhile, psychologists want to study the brain's forgetting strategies to improve therapies for post-traumatic stress disorder and other conditions.
- This isn't "Eternal Sunshine of the Spotless Mind" zapping memories out of people's heads, says Jarrod Lewis-Peacock, a professor of psychology at the University of Texas at Austin.
- Rather, it is figuring out how to help people put their memories into "a mushy state" where they can be updated or reassociated with more positive things.