That Neuroscience Guy - The Neuroscience of Brain Overload Part One - Sensory Overload

Episode Date: February 23, 2024

Do you ever feel like so much is going on that you just can't handle anymore? In this week's episode of That Neuroscience Guy, we begin our discussion on brain overload by discussing sensory overload.

Hi, my name is Olaf 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. Have you ever felt like there's just too much going on in the world, right? You just can't process all the information around you. Well, this is a real thing. We call it sensory overload. And when you get sensory overload, it can cause a lot of interesting and not very enjoyable responses. So on today's podcast, brain overload, part one, sensory overload. So let's just think of regular sensory processing first, all right? And I'm just going to use vision as an example, and we've talked about it before. But if you think of the way vision works, information comes in through the eyes,

it goes through the midbrain, goes to the back of the brain and the primary visual cortex, and there it's processed. And we talked about that a lot in previous episodes, so I won't go through too much. But if you think about what happens with attention, is attention can only let so much through. All right. The whole point of your attentional system, or one of the points of your attentional system, more correctly, is to only let a subset of information through. And that's why you miss

information. So if you're talking to someone, you might miss something else that's happening because you're basically ruling out or disregarding other sensory information. But sensory overload isn't that. It's not discarding information due to an attentional process. That's perfectly normal. So sensory overload is when your five senses, your sense of vision, your sense of sound or hearing things, your sense of taste, your sense of touch, and your sense of smell, basically all these senses are being activated and your brain is just bringing in more information than it can process. And your attentional system is failing for some reason. This information is trying to come in and your brain just can't deal with it. So normally the attentional system would gate this, would call this and block it, but that system isn't doing the right job. So your brain is

overwhelmed. Too much sensory information is coming in. And what does your brain do in that situation? Well, in a sense, it goes back to an evolutionary start point where it activates your fight or flight response and sometimes your freeze response. When your brain is overloaded like this, it sort of goes back to this primitive state and it's scared. Now, if you think about what this means, if you go into a fight mode, for instance, your heart rate and your breathing are probably going to increase. And that's delivering more oxygen to your muscles and getting you ready to do something, right? It's getting you ready to fight. And you might get some sensations like your hands and feet may feel cold, and that's because

blood's being diverted away from them. Your skin may get sweaty or pale. So if you're experiencing sensory overload, you might feel all of those sensations because your brain's fight system is activated. Well, the flea response is very similar. Your brain is getting your body into a state to run away, all right? And you won't feel good when you're in this state. You're going to feel unsafe. You're going to feel fearful. You might panic. Like I said, you're going to feel a bit sweaty, pale and shaky. And this process is because your sensory system is just simply overwhelmed. Too much is coming in and your brain just isn't able to deal with it. So this primitive midbrain fight or flight response is activated. And of course, the other response

option here is to freeze. And what does freezing mean in this instance? Well, basically it means you shut down. Your brain is locking you in place and it's basically saying, I'm not sure what to do. And that's what freeze behavior is. So too much sensation, fight, flight, or freeze potentially. Now, the symptoms of sensory overload. So what are you, you know, what are you actually feeling? Well, I've been over some of them, but to review the key ones, you might feel anxious or you might feel overexcited. Your brain responds differently depending on who you are and previous experience. You might be irritable, right? Too much sensory information. This fight or flight response is activated. You'll definitely feel stressed.

Cortisol is being released and you're in a state of stress. You might feel fear because you're triggering this fight or flight response and a fear is a natural response to fight or flight. And you might even feel panicked. Some people with sensory overload experience physical discomfort and that's because your body is pushing blood around, like I mentioned earlier, getting ready for this fight or flight response. You might be restless. You might not be able to relax. And you basically will feel a strong urge to block input. You're going to want to stop all of the sensory input. You might remove yourself from the situation. You might going to want to stop all of the sensory input. You might remove yourself from the situation. You might feel a desire to get out of that. A classic sensory overload situation is in a large crowd, right? Some people respond very poorly to large crowds. And if you're experiencing

sensory overload in this situation, you're going to want to remove yourself from the situation. And in some cases, you see this more with young children, but they might cover their eyes or cover their ears. And it's simply because they're getting too much sensory information and they're trying a very simple way of blocking it out. In children, especially too, sensory overload can cause meltdowns or tantrums. And you might think that your child is misbehaving, but it could just be their response at a young age, their fight response is being activated. And the way they respond to that is to scream and yell and do all the things that we as parents, you know, we get used to it, but

it's not particularly enjoyable. So if your child does do that, this is for the parents out there, obviously, one thing to think about is look around you and listen to what's happening. Are you in an environment that might promote sensory overload? And to be fair, as a parent, it could also just be that your child is having a meltdown or a tantrum now what causes sensory overload like what are things that can trigger this overwhelming you know response where your brain thinks it's getting too much sensory information well it can be individual things or combinations of things. Triggers basically are a bit individualized. What may trigger one person doesn't trigger another and vice versa. But common triggers of sensory

overload are crowds or tightly packed spaces. In a large crowd, obviously you're going to get lots of visual stimulation, lots of auditory stimulation. But in a tightly packed space, you get that as well because everything's sort of so close to you that you're processing it more. Some people, it's an auditory thing that's a trigger. So large sounds, like large concert level music, fireworks, again, sounds from crowds or festivals for some people sensory overload is a smell thing so strong smells or unpleasant smells they trigger this overloading sensation and these are typically people that aren't used to you know processing that much smell information so if they're exposed to something new or different it might cause sensory overload. You can also get sensory overload from touch.

All right. You know, some people, you know, you might feel a surface or touch something that's just a bit too much for your sensory system. You're just not used to it. And your brain essentially gets overwhelmed. Sudden changes in the environment, light temperature, Um, sudden changes in the environment, light temperature, background noise, this can cause sensory overload and emotion plays a role here too. Our old friend, the amygdala, you know, if I was going to restart the podcast, I would jokingly call it the amygdala podcast. But if you remember the amygdala is our emotional response center in the brain, right? When something emotional happens, our amygdala is activated.

And if your amygdala is firing for whatever reason, it dials up your sensory systems, which makes you more susceptible to sensory overload. So emotional things can trigger sensory overload. Who's susceptible? Well, anyone technically is susceptible to sensory overload. It can happen sensory overload. Who's susceptible? Well, anyone technically is susceptible to sensory overload. It can happen to anybody, but there are certain things that might make you more predisposed to sensory overload. There's something called sensory processing disorder, and this is literally

just a disruption of regular sensory processing in the brain and people with sensory processing disorder can be more susceptible to sensory overload. Generalized anxiety disorder, people with anxiety disorders tend to be more susceptible to sensory overload. People with ADHD, attention deficit and hyperactivity disorder, People with ADHD are more susceptible to sensory overload. Autism is a big one. People with autism are more susceptible to sensory overload. And finally, people with post-traumatic stress disorder are more susceptible to sensory overload. So there's a variety of things that can make you more susceptible to sensory overload. So there's a variety of things that can make you more susceptible to sensory overload, but I want to emphasize that it can happen to anybody.

So what can you do if you experience sensory overload? Well, the biggest thing you can do is figure out what triggers it for you. If you start feeling like you're overwhelmed from a sensory point of view, look around you. What's happening? All right. What is the trigger? Because it's usually pretty common. If crowded spaces set you off one time, they're probably going to set you off again. And then there's people where crowded spaces won't do anything for them, but it might be a smell that sets off sensory overload. And once you've done that, identify exit strategies or safe spaces. Like if you are feeling like your senses are overloaded,

where can you go? You know, what can you do? And then develop a routine. So when it's happening, what are the steps you take to bring yourself back? And of course, if this issue is really strong and powerful, talk to a health professional because it is a real thing. So what is sensory overload? It's basically a situation where too much sensory information is coming into the brain and your brain can't process it all. Your attentional system isn't able to gate it successfully or block things out. And your brain essentially enters a state where the fight or flight or freeze response is engaged. And that results to all the sensations you experience. All right, we're actually doing two parts on this. The second part is going to be on cognitive overload. And this was obviously

sensory overload. I hope you enjoyed it. Don't forget to check out the website, thatneuroscienceguy.com. There's links to our Etsy store and Patreon. Thanks to people that are buying merch and thanks to people that are supporting us through Patreon. Please send in ideas,

thatneuroscienceguy at gmail.com or on X or threads at thatneuroscienceguy. We really want to know what you want to know about the neuroscience of daily life. And of course, thank you so much for listening to the podcast. We're doing our best to get episodes out as, as frequently as we can. We're aiming for one a week. The days vary a bit, uh, and same for the bites, but we are going to keep going. So thank you for subscribing and thanks for the support. My name is going to keep going. So thank you for subscribing and thanks for the support. My name is Olof Krogolsen and I'm that neuroscience guy.

Thank you so much for listening and I'll see you soon for another episode of the podcast.