Science Finally Explains How the Brain Classifies Experiences as Either Good or Bad
And the cellular reason people experience the same event differently
Hiya!
As you probably know, if you and I were to watch a movie together, our opinions of the film, and the context that formed those opinions, would be different. The same is true for actual life experiences. Like, one of my brothers recently realized for the first time that just because we have the same parents doesn’t mean we had the same childhoods. (Both were great, but they’re still different.)
A big reason for this is how we classify our experiences as either ‘good’ or ‘bad.’ But how the brain makes such distinctions have left neuroscientists scratching their heads for many years. However, now they have an idea.
Valence Assignment = Feeling + Memory
How we react to our experiences and the outcomes of those reactions are the result of our emotions, which help create our subjective perception of an experience. And how all of that works in the brain has stumped experts for, well, ever. But there’s one thing experts are pretty sure of—the fundamental reason we have this ability.
Survival.
Fusing a memory with either a “good” or “bad” feeling is what neuroscientists call “valence assignment,” and it helps us navigate (and survive) future events. After all, labeling an event as “positive” or “negative,” determines whether we avoid or seek it out in the future.
But knowing why we have this ability doesn’t explain how it happens on a cellular level — and that’s what neuroscientists really want to know. Thankfully, Kay Tye, the senior author of a study I’ll tell you about in a minute, a professor in Salk’s Systems Neurobiology Laboratory, and a Howard Hughes Medical Institute Investigator, has come the closest (so far) to finding an answer.
Tye figured out the brain has two pathways — imagine two railroad tracks — one leads to a positive association, or “valence” of an event, while the other leads to a negative one. Before her study, scientists knew these paths existed and even where they led, but the problem was they didn’t know what flips the switch, so to speak, to determine which track is used and when.
What’s Going On?
Professor Tye and her colleagues at the Salk Institute published their study on July 20, 2022, in Nature, identifying a molecule responsible for linking feelings to memories in the brain of mice.
Using gene editing, Tye and her colleagues selectively removed the gene for a signaling molecule called neurotensin from the brain cells of mice. Without neurotensin, the mice lost the ability to associate positivity with memory.
They found that while the mice didn’t link positivity with an experience, losing the neurotensin made the mice even better at assigning negative associations, and the mice continued to make negative associations until the neurotensin was released.
On the flip side, when the researchers increased neurotensin to higher levels, it boosted reward learning while dampening negative associations. Considering evolution, this result would make sense—It suggests the brain’s default setting is to pay attention to fear, which alone could keep an organism alive by becoming overly cautious.
Whereas the evolution of neurotensin introduced us to positive learning. Like about what’s safe or what we should seek more of, which could have broadened many aspects of our lives, from our diet, to migrating, new habitats, or taking more risks. In an article by Salk University about the study Professor Tye states:
“We’ve basically gotten a handle on the fundamental biological process of how you can remember if something is good or bad. This is something that’s core to our experience of life, and the notion that it can boil down to a single molecule is incredibly exciting.” and “We can actually manipulate this switch to turn on positive or negative learning."
I mean, come on, this is a pretty remarkable discovery. I don’t know about manipulating our genes to increase our positive associations with memories, though. After all, we need some bad with the good to grow and learn — and seeing as we live in a world of opposites, balancing the positive and negative is ideal.
Then again, anxiety and depression have a habit of unfavorably tipping the scales. Which is one area Professor Tye’s discovery might shed light on. Her research could help explain what’s going on in the brains of people who overly associate negative emotions with their experiences.
For now, though, unfortunately for anyone struggling with depression or anxiety, we can’t permanently increase our neurotensin and boost our positive associations even if we want to because we don’t have an infinite supply of it. Nevertheless, there are still things we can do to inspire more positive associations and level the field.
Train Your Brain
Remember, the brain is a muscle, albeit a unique and mysterious one compared to our others. We may not completely understand how it works, but we do know it’s within our power to train our minds, at least to a degree. Here are three things I’ve found that might help you boost your positive associations.
It’s important to feel our feelings, no matter what they are, but finding the positive in the negative, instead of dwelling solely on the negative, makes a difference.
We can always learn something from a situation, and by focusing on finding the lesson, you’ll be better prepared for the future. It might be challenging at first, but speaking from personal experience, it gets easier with time.
Take a moment to remind yourself of your worth before doing something difficult. Research shows this alone helps soften the blow if something does go wrong.
Lastly, get specific when labeling your feelings. Research shows that getting specific when identifying our emotions matters, and the vaguer you are, the more likely you are to assign a negative feeling to your experience.
Of course, identifying our emotions is easier said than done sometimes.
I definitely have moments when my insides are flipping, climbing the walls, and sinking all at once — what feeling does that translate into? Sometimes it seems easier just to shove it aside and distract myself with my phone rather than sit with it until I can name it — Anxiety.
Perspective Shift
Connecting emotions with memories is such a basic function for us that we rarely even realize how often we do it. Yet this single ability shapes us and determines how we behave in the world. It’s because of it that we navigate and survive life. Now we’re finally learning how such a monumental yet subtle ability happens in the brain.
Everything we’ve been learning about the brain and how it works over the last few years continues to show that we have more power than we acknowledge over ourselves. We may default to assuming the worst, but we also have the ability to find the good. I mean, think about it. You can reshape and define your experiences by becoming intentional about how you label them in your mind. Simply remarkable.
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