Most Shared Moment: Neuroscientist Reveals 4 Hacks to Rewire Your Brain For Growth & Success! - Dr Tara Swart

**Steven Bartlett** (0:00)
In your book, you talk about the mechanisms of neuroplasticity. What are the mechanisms of neuroplasticity and the three factors that have the biggest impact on changes in the brain?

**Tara Swart** (0:10)
So the first one is myelination, and anyone who does a lot of sport, who repeats a certain weight training, will understand that that's what's happening in their muscles. You know when I said, you come here pretty much every day, and you sit with someone, and you interview them, and you're really great at asking questions? That's like something you're super good at, but that because you repeat it, it becomes like a superpower. And that means that what's happening there is myelination. So myelin is a fatty substance that coats some neural pathways, and those pathways become fast pathways. Now there's a reason from evolution why we have some fast pathways and some slow pathways. And the reason is that if you put your hand in the fire, your reflex to snatch your hand out is a fast pathway, but your pain reflex is a slow pathway, because if you were incapacitated by pain, the minute you put your hand in the fire, you wouldn't be able to get away from it. One of the mechanisms of neuroplasticity is becoming even better at something that you're really good at, and that happens through myelination. The most common one, which is something that you're quite good at, but if you had loads of time, you could become really good at it, but you maybe don't have loads of time, happens through synaptic connection. So that's the one that can feel like quite hard work, but if you put in the effort, then you can change your brain. So that means that neurons that already exist in the brain connect up with each other and start to form new pathways. And the third mechanism, which doesn't happen a lot in the adult brain, but it does happen around the hippocampus because we do lay down new memories in life, happens a lot in children's brains, is called neurogenesis. And that is little embryonic nerve cells that float around in the brain actually becoming fully formed nerve cells, neurons and connecting up through synaptic connection and maybe getting myelinated. And there's a factor, a growth factor that's involved in that, the embryonic cell becoming an adult cell, which is called BDNF or brain-derived neurotrophic factor. And trophic means growth. So neurotrophic is growth of neurons. And the things that contribute mostly to that are aerobic exercise and eating dark-skinned foods, yeah.

**Steven Bartlett** (2:25)
Dark-skinned foods?

**Tara Swart** (2:27)
Yeah. So let me just cover the exercise one first, because this is one of my fun facts, which is that if you are regularly doing aerobic exercise, the turnover of those cells in your brain is about 13, 14%.

**Steven Bartlett** (2:40)
So like the amount and the speed in which they like die off?

**Tara Swart** (2:43)
No, the speed in which they go from embryonic to full-grown cell.

**Steven Bartlett** (2:46)
Oh, okay.

**Tara Swart** (2:47)
Yeah.

**Steven Bartlett** (2:47)
Okay.

**Tara Swart** (2:48)
So, because we want neurogenesis to happen.

**Steven Bartlett** (2:50)
Okay.

**Tara Swart** (2:51)
If you haven't been doing exercise for a while and then you start, the rate of cell turnover is like 30%. So it increases after a period of inactivity with new aerobic exercise. So that's my excuse for like being a couch potato half the time and then starting up again.

**Steven Bartlett** (3:09)
Oh, yeah. Who are you kidding? Okay. So it will accelerate the speed in which you're making those connections.

**Tara Swart** (3:17)
Yeah. Making the embryonic cells grow into new cells and then connect up with existing ones.

**Steven Bartlett** (3:24)
So I want to make sure I'm super clear on this. So if I'm trying to develop, if I'm trying to speak a different language by doing exercise that has an impact on...

**Tara Swart** (3:33)
Oh, help you learn and retain memories. Yeah.

**Steven Bartlett** (3:37)
So in simple language, if I'm doing aerobic exercise, my ability to accelerate my neuroplasticity will increase. Yeah. What if it's like not aerobic exercise? What if I'm just lifting big weights?

**Tara Swart** (3:53)
There are benefits to your brain of other types of exercise, but weight training doesn't relate to neurogenesis as much.

**Steven Bartlett** (4:00)
Okay.

**Tara Swart** (4:01)
This isn't so much about language, but it's another example of mind over matter. So this was an experiment done on two groups of weightlifters. Thought you might like this one.

**Steven Bartlett** (4:14)
That's a big compliment. Thank you so much. You think I'm a weightlifter? You can identify as a weightlifter. You looked at me and thought weightlifter.