Scientists Show That You Can Erase Fear by Erasing Memories

Good news, gumshoes. Science has figured out how to erase fears. That sentence is not as sensational as it looks. A team of researchers from Uppsal University in Sweden have developed a technique whereby they can do away with new emotional memories in the brain, like the fearsome ones that might form after an animal attack or a late night mugging. Feeling a little sheepish about flying after a terrible turbulent fight? Well, let’s just zap that fear right out of your head.

In principle, it’s pretty simple. Memories aren’t fully formed the moment something happens. It takes a process called consolidation that trains certain neurons to form bonds and speak to each other to create a memory, and the Swedish researchers hypothesized that interrupting this process could affect the resultant memory. To test this idea, they did an experiment in which they showed subjects images of random, neutral things like pictures of everyday objects or landscapes and administered electric shocks on certain images. This created fear associated with those images. The next time they cycled through the images, the ones that previously came with an electric shock would provoke a fearful response in the subject.

To neutralize the fear, the researchers though, they just needed to neutralize the memory. So in another round of the experiment, they administered the shock just like before but followed it up by repeatedly showing them the image associated with the shock during the period in which the fearful memory was still being formed. This effectively disrupted the memory-making process, and the next time, they cycled through all of the images, the subjects weren’t afraid of the image associated with the shock. This doesn’t do much for people who had a traumatic experience years ago and need to cope with it, but it does shed some light on how memory works.

Memory is one of the great mysteries of neuroscience. How, in a sea of grey matter made up of neurons and synapses, do moments get stored, locked into a person’s conscience? Well, in one sense, we know the basics. Like most things in the brain, the act of creating a memory is simply a matter of neurons interacting with each other, sending signals across synapses, and when those neurons are stimulated enough, they develop into a state of increased sensitivity. A reminder — perhaps a smell or an image — can then trigger these neurons, thereby producing a memory. In order to manipulate a memory, scientists have learned, you have to manipulate these neural connections.

Over the past few years, tremendous progress has been made in identifying the chemicals present when these neural connections are being formed. Fairly recently, a team of researchers in Brooklyn discovered that a chemical compound known as PKMzeta showed up consistently during memory formation. The molecule swarmed around neurons in the memory-making process, so they guessed that interfering with the chemical could also interfere with the formation of memories. They were right. Using a drug called ZIP, they were effectively able to stop memories from being formed. This is not unlike the cognitive training used by the scientists in Sweden, except it could be bottled up in pill form. What’s more powerful about this discovery, however, is that it’s effective for older memories, too.

The big challenge now is targeting specific memories. This is a tough one. Take a soldier who’s been to war and brought back a bundle of horrible memories from the battlefield. Scientists aren’t exactly sure how to target those memories, but they have a pretty obvious theory. If they can find which areas of the brain light up when that memory is sparked, they could inject a ZIP solution into that area. Then, any time in the future that that memory would be recalled, the drug inhibits the neurons from making those connections again.

We’re not in Eternal Sunshine of the Spotless Mind territory, yet, but we’re getting closer. In the meantime, the new research suggests, the best way to avoid being scared after that dog bite or mugging would be to give the dog or the mugger a big hug right after the attack. But frankly, taking a pill sounds like a much better option.

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