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Dude, where’s my car? Brigham researchers find we’re good at recalling approximate location of objects.

Some things get in the way of our impressive, though imperfect, memories, such as other memories of previous times we set down our cell phones or the similar layout of each level of the parking garage where we parked our car.Spencer Colby/Associated Press

Close your eyes and picture the grocery store, the layout of the produce, the location of the milk. Even for an item you’ve never purchased, you likely could walk in and find the general vicinity of where you had seen it last.

Researchers at Brigham and Women’s Hospital sought to capture the brain’s capacity to store such details, suggesting in a new study that people automatically encode vast amounts of data on not only where, but when, they saw something.

“It’s showing a memory capacity that is larger than we would have guessed,” said Jeremy Wolfe, an experimental psychologist with Brigham and Women’s Hospital who coauthored the study. The findings will be published this week in Current Biology.

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Scientists have long understood the shortcomings of memory. People struggle to remember exact descriptions, for example, after briefly being shown more than four items or pictures. For example, if shown more than four photos of cars, and the color was changed on one of them, most people would have a hard time identifying the difference.

But people can recall some things more easily. Previous research has shown people can briefly view 100 pictures and do well at recalling which they had seen before.

Jeremy Wolfe, an experimental psychologist with Brigham and Women’s Hospital who took part in the study on memory.Brigham and Women's Hospital

What researchers didn’t know was whether people could easily recall where those objects might have been placed or when they had seen them.

In a series of experiments for the Brigham study, subjects were shown objects on a grid of squares. Each item was highlighted for two seconds with a ringed red square. All the images were then removed, and participants were tested on their ability to recall if they had seen an item and where on the grid it had been located.

Of the more than 300 different objects shown, many participants could identify the locations of more than 100 of them within one cell of where they had been. Even though each box contained up to seven different objects over the course of the experiment, that didn’t seem to interfere with people’s ability to remember where they were placed.

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In a subsequent experiment, subjects were shown items one at a time, and then asked if they had seen the object before, where on the grid they had seen it, and when through the course of the experiment it had been seen.

Between 60 percent to 80 percent of the time, subjects could accurately identify when they had seen an object within 10 percent of the correct time, according to the study. If they had just guessed, researchers said they would have only been that accurate 40 percent of the time.

Wolfe said the findings underscore the ability of witnesses to accurately remember approximate details, not just where a person saw someone or something, but when. Though such details might not have exact accuracy, the brain reliably and automatically encodes reasonable approximations.

“The time when you can’t remember where you parked your car, it would have been nice to have that memory slide in a bit more precisely. But it’s partial knowledge, not perfect knowledge,” Wolfe said.

Psychologist Elizabeth Loftus, a prominent expert on memory who testified for the defense in Harvey Weinstein’s rape trial, said the new research shows that people can be excellent at remembering where and when objects occurred, even after viewing a large set of objects. But she noted memory doesn’t exist in a time capsule.

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“The ‘object’ memories might be pretty good in the short term, but presumably they too would fade over time, and be susceptible to contaminating influences, just like other memories,” said Loftus, a professor at the University of California Irvine.

Memory experts have long recognized the brain’s ability to remember the spatial layout of their world. Spatial memory allows people to be able to mentally walk through spaces they’ve been before, such as remembering the layout of your childhood home.

The structure of spatial memory is a tool memory champions use to remember vast amounts of information, placing vivid scenes along the route of a familiar place, a technique dating back to the ancient Greeks.

Wolfe said the spatial memory exhibited in the study may be the building blocks for this technique, known as a “memory palace,” harnessing the brain’s innate ability to recall where things are situated.

If we’re so good at locating where we place things, why do we always seem to struggle with where we left certain items? Wolfe himself answered a phone call from his Apple watch, not knowing exactly where his phone was.

Some things get in the way of our impressive, though imperfect, memories, such as other memories of previous times we set down our cell phones or the similar layout of each level of the parking garage where we parked our car.

We also tend to remember all the times our memory failed, instead of the thousands of times our memory got it right. Maybe you can’t find that one kitchen spice, but you accurately located everything else you needed to make a meal.

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This is appreciating how good your memory is most of the time, even if what is salient is the failures,” Wolfe said.




Jessica Bartlett can be reached at jessica.bartlett@globe.com. Follow her on Twitter @ByJessBartlett.