That Neuroscience Guy - The Neuroscience of Anger

Episode Date: March 19, 2023

Someone cuts you off in traffic and you lay on the horn. Maybe your internet cut out for the 3rd time today during an important meeting. It's inevitable that we will experience things that make us angry. But how does our brain handle anger compared to other emotions? In today's episode of That Neuroscience Guy, we discuss the neuroscience behind anger and how it changes our behaviour. 

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. Man, I'm so angry. That person cut me off. I was driving home and they just completely cut me off. Or that friend of mine. Man, I can't believe he did that to me. Okay, so I failed acting 101. But unless you've guessed it,

today's topic is the neuroscience of anger. And I want to point out this came straight from a user request. Someone reached out to me on Twitter at that neuroscience guy and sent me a message and said, you know, what about the neuroscience of anger? That'd be a really cool one to understand. And on that note, I also have to apologize. We do have an email account, that neuroscience guy at gmail.com, but we don't check it that much. We've got so much traffic coming in on Twitter that we kind of let the Gmail account slip. So I logged in today and saw emails from you, the listeners going back, I'm embarrassed to say almost two years. And I'm going to start responding to them as quickly as I can. And we're going to incorporate the ideas that we haven't

done them, but just my apologies. We, we, for both Matt and I, this is not our day job and we get swamped with the Twitter requests. So we just sort of forgot we had a Gmail account. So my apologies to all of you that took the time to email us. But anyway, let's get back to the neuroscience of anger. Well, we know what anger is. It's that feeling where you tighten up a little bit, you know, your, your heart starts beating a bit faster. You can feel that emotion burning inside you and you sort of feel like you're ready to get going. And anger can be an internal thing, right? It can be something where it's just completely within you.

But anger can also be an external thing. You know, you might have thrown something at somebody at some point in your life. You might have reached out and even hit somebody. And obviously it can go beyond that. So we know what anger is, but let's, let's dive into the brain. Well, you're not going to be surprised if you've been listening to the podcast for any period of time that the amygdala is involved, that emotional region of the brain. But I want to, and we're going to talk about this a little bit more later, but I want to explain that the amygdala is not just a

single thing. Like it is, it's a structure, but that structure has sub-regions, if you will. And those sub-regions are responsible for different types of emotional responses. So when we say the amygdala lights up when you're angry, well, the reality is if you look at the amygdala with functional magnetic resonance imaging, PET scans, whatever you want to use, what you find is different sub-regions are responsible for different types of emotional responses. And that's the case with anger. There's a sub-region of the amygdala that seems to fire more when people are angry.

Now, that's not the only part of the anger response within the brain. There's the hypothalamus. Now we talked about the hypothalamus quite a long time ago, so I'll just review it quickly. But the hypothalamus is a midbrain structure that basically regulates your autonomic body systems. So it plays a role in controlling body temperature, which is why you might feel like you're getting hotter when you get angry. It controls blood pressure. So that's another response that might change when you're feeling angry. It also plays a role in mood, which again, guess what? A part of anger. It also does other things too. Hunger and thirst, sense of fullness when eating, sex drive, and even

sleep. But you can see the parts of the hypothalamus that play a role in the anger response. And there's a brain region we haven't really talked about before, which is the periaqueductal gray, the PAG, also known as the central gray. And basically it's also a part of the autonomic function. So that stuff that the hypothalamus is doing, it's a linked structure and plays a role in that as well. So when people are angry, you actually see an increase in activity in the central gray region of the brain as well. So you've got these three brain regions, the amygdala, the hypothalamus, and the central gray region or the periaqueductal gray. And that's the emotional response of the brain. Now, what's important to note is that things can increase the way this system responses.

So for instance, if you're tired, this system responds with more intensity. If you feel threatened, this system can respond with more intensity. And even things like post-traumatic stress disorder, it's been shown that people with PTSD, this system responds more because of the fact that they're experiencing PTSD. And another one would be dementia. When dementia onsets, a classic thing that we see is an increase in anger or aggression. And again, if you look at people that have dementia, you would see that these three brain regions are more activated than someone that doesn't have dementia to the exact same anger stimulus or whatever made them angry.

And there's another part of the emotional response within the brain and that's the prefrontal cortex and again hopefully you can if you've been listening you can start guessing what's going on here but the prefrontal cortex if you remember this is our logical or analytical decision making system right it's the system that's going to say, well, hang on, maybe we shouldn't be angry. Like, is this really the appropriate response? So it's almost a thing that controls the anger response and has an ability to regulate it. And again, if this region is dysfunctional for some reason, for instance, you've consumed too much alcohol, maybe you've had head trauma to the region, again, with dementia or PTSD, if there's dysfunction in the prefrontal cortex,

people become more angry, all right? They have the propensity to be more angry. And the reason is, is that this control structure, which should be dialing down that response, right, and trying to make sure that it doesn't happen, literally can't do that. All right. So if you've got something like PTSD, you've got your emotional system over-responding and you've got your prefrontal cortex under-responding, hence that anger swells up more than if you don't have these things. And of course, this is, you know, one of the things that anything that turns off that prefrontal system, like I said, you know, alcohol used as an example, will get like, you're going to have a greater propensity for being angry.

Now, we might have talked about this combo quite a bit, I would say. This idea that you've got the prefrontal system sort of in a tug-of-war with the emotional system, the amygdala. Well, this is true. This sort of back and forth of these two systems controls a lot of our higher level moods and emotions. But like I was saying with the amygdala, it's a pattern of activity. So it's never the entire amygdala and never the entire prefrontal cortex, but it's parts of these regions that are doing this. So when I just say it's the prefrontal cortex and the amygdala, the reality is, is you would have to hunt through tons of research studies to find out the exact regions within both that are playing a role in this response. And it's important to realize that we don't know

the answer definitively. All right. It's not like I'm just not telling you realize that we don't know the answer definitively. All right. It's not like I'm just not telling you. We literally don't know because sadly with research, each study sort of shows a slightly different pattern of activity. They're generally all in the same region. So all of the anger studies are sort of show the same region of the amygdala activating, but it's sub regions. region of the amygdala activating, but it's sub-regions. So the best way that I think about it is it's a pattern of neural activity and a tug of warp between the prefrontal system trying to shut down anger and the amygdala, the hypothalamus and the periacrytical gray, you know, over-responding.

Now there's other things that play a role in the anger response that are worth mentioning. There's your reward system. So we've talked about them quite a bit, but you know that we have a reward system in the ventral stratum. And basically, if someone does something and you're expected to be rewarded, like whatever it is, that can actually lead to an anger response because you're getting that negative prediction error. We talked about that just on the last episode. But if you remember, outcome expectation. And the reward system, if the ventral stratum is constantly being disappointed, it's not getting the reward that it's seeking,

that will trigger that anger response as well. And basically, people that have impairments to the reward system, things like psychopathy for instance, they are associated with increased anger because this linkage isn't there that's supposed to be there. Another part of the anger response is the social part of the brain, the social network if you will of the brain and again very hard to name specific brain regions. When you get to things like your place in society or your feeling of a social response, you're really talking about a whole brain response. But then if someone doesn't do what you want them to do, so there's a social issue, then you've got the social response system in the brain is firing a

little bit differently. And I want to say this is the social response system. I couldn't list all the brain regions. It's the ones we've already talked about, plus other midbrain regions, plus other parts of the brain. It's almost one of the few things that's truly whole brain, other than possibly the motor system. But even that can come into play. other than possibly the motor system, but even that can come into play. But that's another way this anger response can be triggered. Now, in terms of neuroscience, if you do experience anger, you have issues with anger, what can you do?

Well, at a high level, if you're always angry all the time, then my default response is always you should see a psychologist or a clinical neuropsychologist and find out what's making you constantly angry. But if you just have the occasional anger flare-ups, there are some simple things you can do. Breathing is a simple thing that you can do. If you breathe, you count to 30, that emotional response in the amygdala and the related regions, the pattern of activity is it ramps up very quickly and it dies down. I've mentioned that before. So just breathing works, just sort of taking a second

and just letting your brain calm down. And as I've mentioned before, at the same time, that activity in the prefrontal cortex is going to increase, which will help control that anger response. Distance yourself. Emotional distance is a real thing. If you have constant reminders of what's making you angry, so say it's a, you know, it's a former partner of yours, for instance, and you have pictures of them all over the place. Well, guess what? Every time you see that picture, it's going to trigger an anger response, all right? Well, it might not, but it's definitely going to make it more likely. So emotional distance is a real thing. You've got to remove yourself from the source that's making you angry. And it's literally because every time

you see that source, it's just going to trigger that response. It's just your brain's reaction to the stimulus. It's that simple. And of course, my favorite thing to do is go for a walk. Going for a walk has a calming influence on the brain. It facilitates reduction of these negative emotional responses. And it's just good for overall brain health. So three things you can do, breathe, distance yourself, go for a walk. And in summary, just because I always like to summarize, the anger response in the brain, it's the amygdala, of course, the hypothalamus and the central gray region. But remember, it's subparts of these regions. That's another point I really wanted to make today is it's not the whole thing.

It's a subpart. And I don't think I've made that as clear as I could in the past. But it's also the prefrontal cortex, which is trying to regulate anger within your brain. And that's the neuroscience of anger. Remember thatneuroscienceguy.com. We've got our Etsy store. We're really behind on putting up new material, but we do have some ideas. And there's also Patreon. I say it every time, but it just, it warms my heart when I go on to Patreon and see that people are donating money. And we literally transfer that money to graduate students in my lab to help them become neuroscientists. There's Twitter. I mentioned at

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