It turns out our brains are wired for social interaction,

and when we don't get it, the brain changes and you lose nerve connections in certain parts of the brain.

Before COVID, this issue was more noticeable in older people who lived alone, cut off from their families, and maybe unable to drive.

Researchers saw that the social isolation hastened the age-related cognitive decline, and was a risk for developing Alzheimer's disease.

But with COVID and the ensuing lockdown, we see the evidence of these brain changes in younger people.

You may experience it as brain fog.

Brain fog can be a lot of things, but in general, you can think and process information slower.

You can have trouble finding words.

You can feel mentally tired and draggy, even though you haven't done anything that's physically tiring.

Why would social isolation do this?

Your brain is made up of a network of nerves that connect to one another.

The tighter the connections between the nerves, the better they are able to transmit signals from one nerve to another.

Inflammation loosens these connections as does social isolation.

Social isolation affects your social cognition.

Social cognition is a set of skills that include being able to read someone's emotional expression.

Remembering and recognizing someone whose face is familiar to you.

Being able to interpret someone's tone of voice, and being able to empathize with another person and appreciate that they have their own desires, goals, and intentions.

This last skill is called theory of mind.

Don't know why it's called that. It doesn't quite make sense to me, but that's just in case you read that in the articles that I have referenced.

These skills are learned very early on, but we need social interaction to maintain them.

So some aspect of isolation is that you lose these skills because you fall out of practice.

But then there's the brain changes.

In one of the studies that I referenced, researchers looked at structural MRI data from 32,000 people.

That's a large study.

The people who were socially isolated showed brain loss in the temporal lobes, frontal lobes and hippocampus.

Your hippocampus is important for emotional memories among other functions, and I've said before that people who are depressed have smaller hippocampi.

Now, if you've watched many of my videos, you probably know that I don't like presenting negative information without a silver lining and here it is.

Even if you have brain loss from pandemic isolation, depression, long COVID or something else that causes brain damage,

your brain has the ability to rewire itself, and strengthen loose connections.

This ability is called neuroplasticity.

So one solution to this problem of social isolation is to build up your cognitive reserve.

Cognitive reserve is the mental buffer you have that lets your brain compensate and function even when you have reduced brain volume.

It's like having a backup power generator turn on when the power goes out.

And this is a real thing, and explains why some people can get to their eighties,

and still be very sharp while someone else at 68 is having trouble remembering important events.

The more robust your cognitive reserve, the better you're able to function when exposed to stressors like isolation,

environmental toxins, chronic stress, or anything else that's damaging to the brain.

So you can think of cognitive reserve as your brain's physiological resilience.

Here are five things that can increase your cognitive reserve.

Education.

High levels of social interaction.

Cognitively challenging jobs.

Activities that engage your brain like crossword puzzles.

Reading.

Learning a new language.

And learning to play an instrument.

And then regular physical exercise because exercise stimulates nerve growth, and nerve growth means new pathways and connections.

I explain how that works in my video on how exercise changes your brain.

Building up your cognitive reserve is something you do over a lifetime.

It's not a one and done thing, you have to continuously engage your mind.

An education doesn't mean you have to go to Harvard or Oxford, if you're in the UK.

It's not about the kind of degree you get.

It's about a commitment to learning and processing new information.

When I was growing up without the internet, the way that you gained knowledge was to go to school or go to the library, and look things up in encyclopedias.

But now there is so much information available online that you can get a very advanced level of education from researching and reading from trusted online sources.

If you want to learn a new language, there's online courses for that.

Then there's even free YouTube videos that can teach you a lot about a lot of different things.

You just have to stay curious.

This list that I just gave you isn't exhaustive.

Diet, sleep and self-care also factor in.

But the one thing I like about this list is that most of the factors are within your control.

You may not be able to control how challenging your job is.

In fact, it may be a mind-numbing struggle for you to get through it every day, but you can compensate for the hit that your brain takes from that kind of job by exercising before you go to work.

You can swing that schedule or working on mind puzzles during your lunch hour or when you get home.

And by the way, don't mistake a stressful job for a mentally-challenging one.

Too much work with unrealistic deadlines can make your work stressful, but it doesn't mean it's mentally challenging in a positive way.

Mentally-challenging work should feel satisfying at some level even if it's hard work.

Take a look at this video on what exercise does to your brain.

Thanks for watching.

See you next time.