Scientists just discovered why you can either remember everything or nothing

The seminal sitcom Seinfeld is frequently cited as one of the best television shows of all time. One of the show’s most instantly recognizable episodes is the season 3 installment in which Jerry, Elaine, Kramer, and George just can’t find where they parked their car in a mall parking garage. That episode is remembered so fondly because it’s incredibly relatable. Who hasn’t forgotten where they parked their car?

The human memory is a fickle ability. We can remember something that happened five years ago with crystal clear recollection but draw a complete blank when it comes time to find our house keys or wallet on a busy morning. A new study from the University of York investigated these highly common bouts of location-related amnesia and found that in such situations our memories are usually a seemingly random game of all or nothing.

More specifically, the team of psychologists set out to answer the following question: when a person can’t recall a location-centric memory (where their car is parked, or any other item for that matter), is that memory gone forever or did it just fade with time or due to some other circumstance?

After holding a series of memory tests with a group of participants, researchers discovered that memories regarding locations appear to either be completely forgotten or remembered with precise accuracy. Basically, if you can’t remember where your car is parked right away chances are that memory isn’t coming back. In this way, location-centric memories come down to accessibility; if you can retrieve the memory it will be accurate and correct, but the trick is remembering.

Over 400 people between the ages of 18 and 35 took part in this study, which was conducted online.

“Our study set out to discover what kind of information is lost when forgetting occurs and we show that forgetting involves losses in memory accessibility with no changes in memory precision,” says study co-author Dr. Aidan Horner in a university release. “The question of how we forget is an important one. Rather than being something purely negative, forgetting may actually be beneficial to the decision making process. Our brains need to be able to discard distracting or unnecessary information so we can prioritize core information that helps to guide decision making.”

Each person was told to look at a series of words placed in circular patterns and memorize the locations of each word within the circle. Then, their memories were tested by being shown the words and asked to remember where each word should go within the circles. Some people were tested just 10 minutes after memorizing the circles, while others had to wait as long as four days.

While participants who were tested after a few or more days didn’t remember all of the words’ locations with the circle, the locations they did recall were just as accurate as people tested shortly after learning the words initially.

So, this indicates that it isn’t precision or accuracy that disappears when we forget a memory, but accessibility.

Another experiment was held in which participants looked for a pattern of words in specific spots within the circles (words referring to colors always on the left side, for example). Participants who picked up on these patterns were able to remember more generalized word-location areas, but the precision of their memories decreased.

“We found that when participants were able to learn the locations of words via a pattern, there was a trade-off between accessibility and precision. What you gain in the number of word-location associations remembered, you lose in the precision with which you remember them,” Dr. Horner explains. “For example, if you parked your car in roughly the same spot every day, you’d be more likely to remember where you parked it, but perhaps be less able to remember precisely where you parked it that specific day – you’d remember the rough, but not the precise, location.”

The full study can be found here, published in Nature Human Behaviour.