Saving the Moment

Want to remember an image forever? Don’t focus on remembering it, but on experiencing it, says a new study.

This isn't just A scene - it's THE scene. Note the differences.

Working to recall a mental image – or to save one in memory – activates your parahippocampal cortex (PHC), a brain area that’s crucial for the formation of memories of visual scenes. If the PHC is already hard at work when you see a new image, you’re much less likely to remember that image later – but if the PHC is primed to absorb new information, a new image is far more likely to be stored.

It’s a pretty simple idea, but it adds an interesting new twist to decades of memory research: though it’s true that some events may be more memorable than others, how ready we are to remember something also makes a major difference.

See, there’s already been a lot of research into the area of memorability – what makes some events easier to remember than others. For instance, frightening events can trigger activity in the amygdala, which helps intense memories quickly imprint themselves into long-term storage. But when it comes to more ordinary visual memories, it hasn’t been quite as clear why our minds save some images much more vividly than others.

To find out what was going on here, a team led by MIT’s John Gabrieli decided to measure activity in the PHC, the journal Neuroimage reports. While volunteers lay in an fMRI scanner, the team showed volunteers 250 images of indoor and outdoor scenes:

Activation in PHC was monitored in real-time, and scene presentations were triggered when participants entered “good” or “bad” brain states for learning of novel scenes.

In other words, the researchers waited until the fMRI scanner showed that a volunteer’s PHC was activated to a greater or lesser degree, and tried showing the subject a scene when his or her PHC was in either of those states, to look for correlations between PHC activation and memory for scenes.

Later, the team showed the volunteers 500 photos of similar scenes – including the 250 they’d already seen – and asked them which ones they remembered from the first time. And when they’d finished subjecting their volunteers to the World’s Longest Vacation Slideshow, the researchers found that the better the subjects remembered a particular scene, the less active their PHC had been when they’d first looked at it.

The PHC activation patterns weren’t always exactly the same, but the correlation between lower PHC activity and improved recall was impossible to ignore:

These findings show that neuroimaging can identify in real-time brain states that enhance or depress learning and memory formation, and knowledge about such brain states may be useful for accelerating education and training.

In short, these findings could help us understand when it’ll be most productive to study for a test, or prep for a new project. Even closer to home, these results hint at a simpler idea: the best way to ensure we hold onto a visual moment is to stop trying so hard to remember it, and just exist in it. As I’ve mentioned before, memory can be a slippery thing – sometimes, the harder we try to dig up a memory, the harder it gets to find it.

In the future, the researchers hope they’ll be able to understand which brain processes help make people more or less receptive to different kinds of new knowledge:

The use of functional neuroimaging as a causal, rather than correlative, tool to study the human brain may open new insights into the neural basis of human cognition.

That could be good news for those of us who never forget a face…but can’t always put the right name to it.

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