That Neuroscience Guy - The Neuroscience of Socioeconomic Status

Episode Date: June 14, 2022

Our upbringing is based on where we're born, who we're born to, and a considerable amount of other things. We have an umbrella term for this, socioeconomic status. But does your socioeconomic status affect your brain? In today's episode of That Neuroscience Guy, we discuss how our background has profound effects on the development of our brains. 

Hi, my name is Ola Kregolson, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to the podcast. Where we're born and who we're born to has a massive impact on brain develop and subsequently cognition. We term this construct socioeconomic status, and it's quite complex because it involves multiple factors. For example, socioeconomic status is tied to household income, how much money your parents earn, the material resources that your parents have available to them, but also the material resources that you have available to you.

It is tied to the education and occupation of your parents. It involves family dynamics, how the family interacts, and it also even includes the neighborhood where you're born. All of these things can work together to impact our brain and the brain systems that underlie cognition. Now, what's cool about this is neuroscience research is peering in this to basically figure out, well, how? How does socioeconomic status impact our brain development? Well, there's sort of three primary factors that are used to explain the impact of socioeconomic status on brain development and then subsequently cognition. The first are prenatal factors, the second is parental care, and the third is cognitive

stimulation. Now, of course, there might be other factors, but those are the three primary ones I'll talk about today. And these factors influence brain development. And because they influence brain development, they subsequently impact cognition. So basically how well our brain works. And that leads to impacts on academic achievement and also even mental health. And this can continue not just through your childhood years, but it obviously carries on into your adult life. Now, studies that have looked at childhood socioeconomic status have found that some brain systems are more impacted than others. So the largest effects of socioeconomic status are seen in language processing, in the language areas of the brain. But there's also impacts on executive function.

We talked about executive function back in season one, but basically executive function is like your higher level thinking, if you will, your ability to rationalize and make decisions. And socioeconomic status also impacts working memory, declarative memory, and even spatial cognition, our ability to process spaces. So research that focuses on language development have basically shown that children from a low socioeconomic status background have reduced language abilities. For example, in one early study, it was estimated that American three-year-olds who are from professional families, in other words, families with high socioeconomic status, had twice the vocabulary of children of the same age from

families of low socioeconomic status. And what's crazy about this is it's not just this lack of money. Well, it is the lack of money and these other things that are a part of socioeconomic status, but it actually leads to differences in brain structure. So if you do MRI scans or use EEG to peer into the brain of children with different levels of socioeconomic status, there's actually structural differences. And those differences aren't born there. They are created by the socioeconomic status, although some things can occur prenatally. We'll talk more about that in a bit. So for instance, people with high socioeconomic status had more activity in their left language areas relative to people from low socioeconomic status. And there were also, like I said, structural differences in these brain regions that wiring was actually different because of SES.

There's also, like I said, impacts on executive functions such as working memory. Basically, it's been shown that children from low socioeconomic status backgrounds have poor working memory skills, have problems with decision making, and have problems with other tasks associated with the prefrontal cortex. And as with the language studies, again, what we see is if you peer inside the brain of children from low SES backgrounds, their brain is different. The prefrontal cortex isn't as developed. And if you measure neural activity, you don't see as much activity in the prefrontal cortex.

Now this, in both instances, language and executive function, this continues into adulthood. These people are sort of behind at the early stages, and generally they tend to stay behind, but not always. And I'll talk a little bit more about that at the end. But there's also differences of being seen in attentional systems. People from low socioeconomic status backgrounds have trouble paying attention. And the parts of the brain, the parietal cortex, again, something we talked about in season one, that part of the brain isn't as active when someone's trying to pay attention. And there's also structural differences again. And this is true of the other things I mentioned, reduced ability and emotional processing. So guess

what? The amygdala is left less active. And at the same time, there's structural differences in the amygdala. And this is also true in terms of cognitive states that can emerge. So for instance, children from low socioeconomic status backgrounds have been shown to have higher rates of depression, anxiety, attentional problems, behavioral disorders. And again, this is all tied to these underlying differences in terms of the brain function and what's going on inside the brain. So across the board, you see differences in terms of structure and in terms of brain activation.

But what's driving this? Well, there are prenatal factors that occur, like I said at the outset, and there is also the parental factors. And finally, there are these sort of cognitive factors that come into play as well. So for instance, kids from low SES backgrounds have been shown to have higher levels of lead in the blood, so bigger exposure to toxins. And lead is a neurotoxin that affects IQ and basically is being shown to affect things like school achievement and reading ability. Nutrition. People from low SES backgrounds tend to have a different nutritional content to their diets, usually due to access issues,

but that leads to differences in brain function. Prenatal drug and alcohol exposure is being shown to be more prevalent in people from low socioeconomic status backgrounds. And we know fetal alcohol syndrome, for instance, this can impact brain function. And finally, there is stress. People from low socioeconomic status backgrounds tend to have more stress in their lives, and chronic stress has been shown to have an effect on brain function. People that basically live in environments of constant stress have less brain activity to certain things and structural differences as well. So the low socioeconomic status environment exposes children to these things that basically affect the way the brain develops. So what can we do about it? Well, basically, low SES is a societal problem that needs to be fixed and addressed.

As long as we have people that are put into low socioeconomic status backgrounds, there are going to be differences in brain function. Now, this isn't everybody. There are obviously plenty of success stories of kids coming from low socioeconomic status backgrounds that are geniuses and achieve and do all these amazing things. And that's true because we all have individual differences and not everyone is impacted in the same way. But on average, these findings are true. So my personal two cents and my belief, like I've said, this is a societal problem that needs to be addressed. We need to remove or at least find ways to reduce low socioeconomic status so we can let our children have healthier brains and better mental function

overall. Okay, that's a little bit on socioeconomic status in the brain. Just a reminder, if you've got show ideas, we're already starting to think about season four. We haven't even finished season three yet. We're starting to think about season four. So haven't even finished season three yet. We're starting to think about season four. So please send us an email, thatneuroscienceguy at gmail.com or follow me on Twitter at thatneuroscienceguy. And feel free to DM me. I don't mind. Just say, hey, I got an idea for a show. What do you think about this?

Of course, we have Patreon where you can support us. You can find links to Patreon and see how it works on our website, that guy.com and of course uh the etsy store we've made a couple shirts we're planning on making a couple more feel free to buy one the money goes to grad students in my lab i take none of it personally and it would really help us out because these are the grad students that support the podcast i've got two of them one matt that helps with sound editing and another L and they are our social media coordinator and help planning all of that kind of stuff. And of course, please subscribe to the podcast. Thank you so much for listening today. My name is Olof Kregolsen and I'm that neuroscience guy. I'll see you on Wednesday for another neuroscience bite.