That Neuroscience Guy - Why is social media so addictive?

Episode Date: February 15, 2021

On this episode I discuss why social media is so addictive - the neuroscience behind why we keep going back to see if someone has liked our post.

Hi, my name is Olof Kregolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to the podcast. Social media, it comes in so many forms, Facebook, Instagram, Twitter, TikTok, and so many others. But why are we so addicted? Why do we keep going back to it? Why, when we look at the amount of time we spend on our devices, is so much of it devoted to social media?

On today's podcast, we're going to talk about the neuroscience of social media and why it's so addictive. To understand why social media is so addictive, we have to talk a little bit about how we learn and the neuroscience about how we learn. You might have heard an old adage that we learn from our mistakes. Well, it turns out that that's not really true. We actually learn when our expectations differ from our outcomes. Here's what I mean by that. Imagine you are back in school and you write a test. You have an expectation of how you did on that test. Imagine you think you got a B. That's your expectation. Then the teacher grades that test and passes it back to you and you found out you actually got a D. That's the outcome.

In this case, your expectations and your outcomes differ. And in neuroscience and in a lot of other fields like computer science and economics, we call that a prediction error. A prediction error is when our expectations and outcome differ. And in the case of the test, that's a negative prediction error because things were worse than expected. Let's look at another example. Imagine it's payday and you check your bank account and all of a sudden there's more money than you thought there would be. That's a prediction error. You had an expectation that you were going to get one amount of money, and the outcome, when you actually checked your balance, was considerably larger.

So that's a prediction error. Your expectations and outcomes differed. And, like I say, that's a prediction error. Now, how does this relate to us being so addicted to social media? Well, we have to dive into this a little bit deeper. And we have to look at the neural basis for prediction errors. Now, it turns out that this story is going to be about a neurotransmitter called dopamine. Some of you will have heard about dopamine because it plays a role in so many things.

For instance, changes in our dopamine levels can be related to depression. And if you get Parkinson's disease, that essentially is a problem with your midbrain dopamine system. However, dopamine also plays a crucial role in learning. Now, this goes back to some early research by Dr. Wolfram Schultz. He was studying monkeys and he was actually interested in reward. The early stories on dopamine was that dopamine was associated with reward. There's a very classic study from 1954 by Olds and Milner where they put some rats in the box and there was a lever in the box. When the rats pressed the lever, they received a little shot of dopamine.

And what Olds and Milner found was that the rats kept pressing the lever over and over and over again, to the point that they ignored food and water and just about everything else. They just wanted to press the lever and get that shot of dopamine. Based on that work, people for a long time thought that dopamine was associated with pleasure. It was the neurotransmitter that was released when we experienced something pleasurable. And that's partially true. Let's go back to Wolfram Schultz. What Dr. Schultz did was he was studying the dopamine response in monkeys and he was using a very simple paradigm. In his

experiment, what he did is he basically replicated the work of Pavlov. Monkeys were shown a cue. Imagine a bell that dinged and that cue, when it dinged, it predicted that a reward was going to be given. Juice, for instance. Now, early in learning, when the bell dinged, the monkeys didn't respond because they didn't know what it meant. And more importantly, if you looked at the activity of the midbrain dopamine system, there was no change there. However, when the apple juice was given, all of a sudden there was an increase in the firing rate of dopamine neurons. So that kind of sounds like Olds and Milner. Dopamine was firing when a reward was given.

And Schultz thought that was the case. However, they kept the experiment going. They kept dinging the bell and giving the monkeys reward. And something really interesting occurred. What Schultz and colleagues observed was that there was an increase in the firing rate of dopamine neurons to the bell. And when the reward was given, there was no change in the firing rate of dopamine neurons. This made them stop and think. If dopamine was supposed to be associated with rewards, why was there no change in the firing rate of dopamine neurons

when the reward was given after the monkeys had been well-trained? And why was there a change in the firing rate of dopamine neurons to that bell? Well, if we think of prediction errors, we can explain this. Early in learning, the monkeys weren't expecting a reward. Remember, they didn't know anything about the bell. So when the reward was given, things were better than expected. They had no expectation and there was an outcome. And the dopamine system fired.

However, once the monkeys had learned the association between the bell and the reward, think about what happens. All of the sudden, the monkeys hear the bell, and they have learned that that bell predicts a reward. Now, they weren't expecting the bell to occur, but that triggers this response. It's a prediction error. It's the indicator that things are going to be better than expected. And when the reward is actually given, there's no prediction error because the monkeys are expecting to get the reward. I'll give you an example you might be able to relate to a little bit better. Let's go back to payday. If you wake up in the morning on payday and you realize it's payday,

there's a prediction error because all of a sudden things are better than expected. You go, wow, it's payday. But when you actually check your bank account balance and you got the money that you expected to get, there's no prediction error because you were expecting to get paid that amount of money. Does that make sense? So where are we at and how does this relate to social media and why it's so addictive? Essentially what I've told you is that prediction errors are a mechanism that your brain uses to learn about things. What things are important, what things aren't. And they also involve this neurotransmitter dopamine. Your brain signals prediction errors by releasing a little shot of dopamine. It's a little reward signal that occurs when these violations of expectancy

are present. All right, we can finally tackle social media. Why are we so addicted? Well, when you log into social media and you see those little likes, those are little prediction errors. Things are better than expected. You weren't expecting to be liked, and all of a sudden you were. And that releases those little shots of dopamine. And it's an addiction. You want those little rewards. So you keep going back to social media, hoping for another prediction error, hoping for another shot of dopamine. And every time you get one, and every time you get one, it makes you want to go back even more. Sadly, this is also why the negative things impact us on social media so much.

If you log into your social media account and you see something really negative, you weren't expecting to see that. You were expecting life to be just the way it is. And all of a sudden, you get a very negative comment. That's a negative prediction error and things are worse than expected. There's still some debate about how your brain encodes negative prediction errors. But one prominent theory is that there's a decrease in the firing rate of dopamine neurons when we experience these negative prediction errors, and that prompts us to change behavior. You could imagine that every time you logged into Facebook, you had a negative comment. It wouldn't take too long before you stopped looking at Facebook. So there it is. That's why social media is so addictive. It's

because of these little prediction errors and these little releases of dopamine. So it might not be that surprising for you to find out that dopamine underlies a lot of addictive behaviors. For instance, drugs like cocaine. One of the reasons that cocaine is so addictive is you're sitting there and you haven't done any cocaine and all of a sudden you do some. Things are better than expected. Cocaine causes this rapid release of dopamine, which is the ultimate prediction error. And your brain craves these prediction errors. So you keep doing cocaine because you keep wanting these prediction errors. And the addiction is formed.

And these prediction errors, the ones from cocaine, you can almost think of them as super prediction errors. The burst of dopamine that's released is so much bigger than anything else that it keeps you coming back for more. On a more positive note, this is also why we like watching videos of cute animals. They cause these little prediction errors. We see the cute animal and all of a sudden there is a little prediction error and we feel good about ourselves. The little burst of dopamine. There's another part to cute animals, though. If you think back to the first episode, they also trigger an emotional response in the amygdala, that warm fuzzy.

So you've kind of got a double weapon with cute animal videos. You've got the little prediction error, because all of a sudden you see the cute animal, and there's your dopamine response. And at the same time, your amygdala is active, the emotional response. So you want to keep watching cute amygdala is active, the emotional response. So you want to keep watching cute animal videos and they also make you feel better.

Bear in mind though, that if you watch them too much, those prediction errors will become expected and all of a sudden they won't be as cute as they used to be. So this is the inherent problem with social media. It's an addictive substance. Or more importantly, social media and all those likes, they cause this dopaminergic reaction, this prediction error that signals that things are better than expected. And every time you get a like, it's another prediction error and you want to come back for more.

Probably the last thing to talk about with this is why. Why do we like positive prediction errors? What's the big deal? Well, there's still a lot of debate about this, but if you take a utilitarian approach, you could say that as human beings, we're constantly craving reward. We're looking to get to a place where things are good.

And these prediction errors signify that things are better than expected. So each time you encounter one, you're climbing a slope towards a place you want to be. Now, these prediction errors can occur in a lot of ways. And in this case, it's just social media, but you're still triggering this underlying mechanism, this mechanism that signals to you that things are better than they're expected expected and that you're on the path to attaining rewards. I should also add there's another aspect to social media, and that's novelty. If you think about social media, it's always changing. There's always something new. Every

time you open up Facebook or Instagram or Twitter or TikTok, there's something else there. And we also crave novelty. And guess why? Novelty is a form of prediction error. You weren't expecting to see the video on TikTok of the person doing the incredible backflip off the roof into a pool. And you have a prediction error. Things are better than expected. And it's important to point out that your emotional system keeps staying tied to this. Your emotional system has positive responses to things with positive emotional valence, and it has negative responses to things with negative emotional valence. But at the end of the day, it ties back down to these prediction errors.

Things are better than expected, so you keep going back for more. And that's it. That's why social media is so addictive. Every time you see that like, whether it's on Facebook, Instagram, Twitter, or TikTok, it causes a positive prediction error. And that positive prediction error results in a release of dopamine and your body craves that. It craves reward.

That's what it's chasing. My name's Olive Kregolson and I'm that Neuroscience Guy. You can follow me on Twitter, at That Neurosci Guy, or you can check out my blog and where the podcast is hosted on thatneuroscienceguy.com. Thanks so much for listening, and I'll see you on the next episode.