Can You Forget Things On Purpose?

Illustration: Elena Scotti (Photos: Getty Images, Shutterstock

Memory’s ungovernable, a ceaseless shaming pain: you’re either scrambling to retrieve it (rooting around for keys, or the name of some acquaintance) or you’re scrambling away from it, wishing it wouldn’t toss up, for the seven hundredth time, this or that miserable incident (deaths, bad dates, awkward elevator talk, trauma beyond the scope and tone of this parenthetical, etc.). Eternal Sunshine posited a medical remedy for this latter scourge - but is such a thing actually possible, outside of twee pseudo-indie movies from the early aughts? Can you actually forget things on purpose? For this week’s Giz Asks, we reached out a number of psychologists with different viewpoints to find out.


Tracy H. Wang

Research Affiliate Postdoctoral Fellow of Neuroscience at the University of Texas at Austin, who studies the neuroscience of intentional forgetting, among other things

Absolutely, yes, you can. We have decades of behavioural laboratory research to support that.

Until recently, ‘intentional forgetting’ in a scientific context involved drawing attention away from an item, or disengaging with a memory. But the research I’ve published recently has presented a counterintuitive finding: that when you draw a little more attention to a memory, you have a better chance of forgetting it.

In one of my studies, we put people in an MRI scanner and showed them pictures, followed by an instruction - to remember a previous item, or to forget it. We were able to read out how strongly they were processing all of this, using machine learning methods to decode patterns in their brain activity.

What we found was that when people engaged more with the information they were trying to forget, they were, in certain conditions, more successful at forgetting it. If they engaged with the memory too much, they strengthened it. If they completely disengaged the memory, it wasn’t modified at all, but if they engaged just a little bit, or a moderate amount, then the memory was more susceptible to forgetting, a finding we validated by testing them behaviourally later on.

I think a real takeaway from this is that we have an impact on whether memories are remembered or forgotten. Memory is a malleable, modifiable thing: we’re changing it all the time.

That said, I am not yet comfortable with this type of data being prescriptive. Once we have a better understanding of how memories can be forgotten, then we can design treatments that can be better vetted to help people intentionally rid themselves of these types of unwanted memories. The goal here is to increase our fundamental understanding of how the brain works.

Justin Hulbert

Assistant Professor of Psychology and Director of the Memory Dynamics Lab at Bard College

Although it’s difficult (if not impossible) to convincingly show that a memory has been permanently and completely forgotten, it’s fairly easy to forget something in the moment. We all know this from our everyday experiences. But recent research has given us an extraordinary new window into how forgetting happens in the brain.

This work has revealed that efforts to forget or suppress unwanted memories can have long-lasting consequences. As such, motivated forgetting can be a powerful tool used to shape one’s inward life and outward perspective. We in the Memory Dynamics Lab at Bard College continue to explore the mechanisms and consequences associated with various forms of forgetting.

Let’s say I am motivated to forget an embarrassing episode, for example. As a quick solution, I might try to change my context. The extent to which one’s current physical context (one’s location) and mental context (whatever happens to be on one’s mind) overlap with those present during the original event makes it easier to remember it.

Thus, if our goal is to reduce the risk of the memory coming to mind, we are better off getting as far away as possible—physically and mentally - from the original event, perhaps by daydreaming about a far-off vacation. Research on directed forgetting has substantiated this claim. We could also attempt to establish new, more positive associations with reminders of the original event, or, instead, retrieve substitute thoughts in place of the embarrassing memory.

In the laboratory, we have seen how practicing memory suppression can help block retrieval of the original, unwanted memory and inhibit the likelihood of remembering it later. Similarly, it seems possible to “shut down memory lane” by orienting away from memory retrieval and focusing instead on the present environment (e.g., paying attention to the visual form of the reminder itself).

This also has been shown to reduce the future accessibility of the targets of memory suppression. However, this particular strategy (in contrast to the thought-substitution) is associated with a systemic down-regulation of an area of the brain called the hippocampus, which is known to support both the retrieval of old memories and the formation of new memory associations.

While disrupting retrieval in this manner may be in line with the goal of stopping an unwanted memory intrusion, disrupting encoding abilities risks an unwanted side effect of memory control: amnesia for events that occur around periods of suppression - what we call an “amnesic shadow.”

This illustrates just how important it is to investigate both the potential benefits, as well as the unintended consequences, of attempts to control one’s memory—be they strategic or through the administration of new medications out there that blunt the impact of emotional memories.

Peter F. Delaney

Associate Professor of Psychology and Director of the Cognition, Learning, and Memory Lab at the University of North Carolina at Greensboro

Forgetting is one of those words, like “justice,” that we all think we understand, but when you get down to it, we don’t all agree on what it means. Aristotle thought of forgetting as literally erasing memories, like melting an impression off a block of wax. I think this is wrong.

When I say I “forgot,” it means it’s still in my brain, but didn’t come to mind. Memory prioritises what comes to mind. After all, you wouldn’t want a cue like “my girlfriend’s name” to trigger all of your past girlfriends’ names at once. To be useful, we need the most useful memory, not all the others.

Our control over what we are thinking about means we can forget things in this sense, even if we can’t permanently erase them. In lab studies on directed forgetting, we tell people to study something and then forget it on purpose. People show forgetting, and can’t “unforget” (even when offered money).

Psychologists Lili Sahakyan and Colleen Kelley argued that directed forgetting occurs because we deliberately thing of something else, which changes our current mental state. After that, the mental state we’re in is not such a great match for the information from before, which makes it harder to remember. You can get the effect if we ask you to daydream about your vacation or your childhood home, even if we don’t tell you to forget.

When people ask me about forgetting on purpose, they often have something terrible in mind that they want to forget. Psychologists Jennifer Talarico and David Rubin found that trauma memories are no less forgettable than other memories. However, if we think about a trauma a lot, a lot of things become associated with it.

This is what people mean when they say something is “triggering” - it’s associated in their minds with some bad event from their life, and it brings it back up. Getting over trauma memories requires hard work, because you have to make something else come to mind first in response to those triggers. Therapy is still not going to erase the memory, but it might help you to have it come to mind a lot less often, or make it hurt less when it does.

Jutta Joormann

Professor of Psychology and Director of the Affect Regulation and Cognition Lab at Yale University

Wouldn’t that be nice if we could forget things on purpose? The awkward first date, the embarrassing mistake in the middle of the important presentation, or the images of the terrible car crash we witnessed.

We do forget, a lot of information all the time - so that’s not the problem but it seems like it is not up to us to choose what to remember and what to forget and often the things we want to forget have emotional content that scares us or makes us sad - and these memories seem particularly sticky.

Over time memories fade, even the highly emotional ones, but it is not clear that we ever fully forget them. We may stop thinking about them (and try to do that deliberately) but if we make an effort to recall what happened we will still be able to (even if not all the details).

So we may forget the details but we are unlikely to forget that it happened. Indeed, there is some work suggesting that if we make a deliberate effort to forget (or not to think about something), it may come back to haunt us.

This was found in the famous “White Bear” experiments conducted by Daniel Wegner who found that if you instruct people to freely think about anything they want as long as it is not a “White Bear”, images of white bears will keep popping into their head and the more they try not to think about it, the more they will have white bears pop up.

Indeed, it seems that trying not think about something or trying to forget something may mean that it takes on special informational value which will lead to it becoming particularly difficult to forget. Also, research on traumatic memories suggests that sometimes trying to forget has the opposite effect and the inability to remember details may lead to reduced control over when and where memories will come up.

Robert A. Bjork

Distinguished Research Professor, Cognitive Psychology, UCLA, whose research focuses on human learning and memory, among other things

We can’t voluntarily forget in the sense of outright erasure. But in another very realistic sense, we are capable of voluntary forgetting, and it can happen pretty automatically. Let’s say you’re driving and I’m giving you directions. I might tell you to take a certain exit.

I might then tell you to re-route, because it turns out the exist is closed. That, in effect, is an instruction to forget the first thing I told you. Or let’s say you’re looking for your car after work—you need to remember where you left it this morning, not yesterday.

Many years ago I started research into what came to be called directed forgetting. In controlled experiments we would give somebody something to remember—a list of words, say—and then at some point we’d say: ok, that list was just for practice, here’s the real list. This improved their recall for the second list, but severely worsened their recall of the first.

Sometimes people who are victims of child abuse that involves a parent are motivated not to keep thinking about those abusive incidents. They may choose instead to think about the family picnic, and camping trips, and other things from their past, and that will gradually make the other things less recallable.

It’s not an erasure: the way memory works, forgetting in particular, is that things become inaccessible, but they’re not gone. If they’re presented again, they can usually be recognised; they can be relearned.

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